Sleep Medicine

Disordered sleep is associated with a significantly increased risk for stroke, new research shows.

Results of a large international study show stroke risk was more than three times higher in those who slept too little, more than twice as high in those who sleep too much, and two to three times higher in those with symptoms of severe obstructive sleep apnea.

The study also showed that the greater the number of sleep disorder symptoms, the greater the stroke risk. The 11% of study participants with five or more symptoms of disordered sleep had a fivefold increased risk for stroke.

Jupiterimages/Thinkstock

More symptoms, more risk

Previous research shows severe OSA doubles the risk of stroke and increases the chance of recurrent stroke. A 2019 study showed that people with insomnia had a small increased risk of stroke.

“Both snoring and extremes of sleep duration have been previously associated with an increased risk of stroke in observational research, but less is known about other symptoms of sleep impairment, with less consistent findings,” Dr. McCarthy said.

Prior studies have also generally come from a single geographic region, which Dr. McCarthy noted could limit their generalizability.

For this effort, investigators used data from 4,496 participants in INTERSTROKE, an international case-control study of risk factors for a first acute stroke. About half of the participants had a history of stroke.

Using information collected from a survey of sleep habits, researchers found an elevated stroke risk in those who received less than 5 hours of sleep per night (odds ratio, 3.15; 95% confidence interval, 2.09-4.76) or more than 9 hours of sleep per night (OR, 2.67; 95% CI, 1.89-3.78), compared with those who slept 7 hours a night.

Participants who took unplanned naps or naps lasting an hour or more (OR, 2.46; 95% CI, 1.69-3.57) and participants who reported poor quality sleep (OR,1.52; 95% CI, 1.32-1.75) were also at an increased risk for stroke.

Symptoms of OSA were also strongly associated with increased stroke risk, including snoring (OR, 1.91; 95% CI, 1.62-2.24), snorting (OR, 2.64; 95% CI, 2.17-3.20), and breathing cessation (OR, 2.87; 95% CI, 2.28-2.60).

Stroke risk increased as the number of sleep disturbance symptoms rose, with the greatest risk in the 11% of participants who had five or more symptoms (OR, 5.38; 95% CI, 4.03-7.18).

“This study finds an association between a broad range of sleep impairment symptoms and stroke, and a graded association with increasing symptoms, in an international setting,” Dr. McCarthy said.

Researchers aren’t sure what’s driving the higher stroke risk among people with sleep disturbances. Although the study did control for potential confounders, it wasn’t designed to get at what’s driving the association.

“Sleep disturbance may also have a bi-directional relationship with many stroke risk factors; for example, sleep disturbance may be a symptom of disease and exacerbate disease,” Dr. McCarthy said. “Future interventional studies are required to determine the true direction of the relationship.”
 

A marker of stroke risk

Daniel Lackland, DrPH, professor of neurology at the Medical University of South Carolina, Charleston, said the findings provide additional evidence of the link between sleep and stroke risk.

“The results confirm sleep disorders as a potential marker and part of the risk profile,” he said.

Collecting information about sleep using a validated assessment tool is an important piece of clinical care, Dr. Lackland said, especially among patients with other stroke risk factors.

One limitation of the study was that data on sleep was collected only at one point, and participants were not followed over time to see if changes in sleep affected stroke risk.

“This is an important point and should be a focus for future studies, as it is critical in the design of interventions,” Dr. Lackland said.

The INTERSTROKE study is funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, Astra Zeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MERCK, Sharp and Dohme, Swedish Heart and Lung Foundation, U.K. Chest, and U.K. Heart and Stroke. Dr. McCarthy and Lackland report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Disordered sleep is associated with a significantly increased risk for stroke, new research shows.

Results of a large international study show stroke risk was more than three times higher in those who slept too little, more than twice as high in those who sleep too much, and two to three times higher in those with symptoms of severe obstructive sleep apnea.

The study also showed that the greater the number of sleep disorder symptoms, the greater the stroke risk. The 11% of study participants with five or more symptoms of disordered sleep had a fivefold increased risk for stroke.

Jupiterimages/Thinkstock

More symptoms, more risk

Previous research shows severe OSA doubles the risk of stroke and increases the chance of recurrent stroke. A 2019 study showed that people with insomnia had a small increased risk of stroke.

“Both snoring and extremes of sleep duration have been previously associated with an increased risk of stroke in observational research, but less is known about other symptoms of sleep impairment, with less consistent findings,” Dr. McCarthy said.

Prior studies have also generally come from a single geographic region, which Dr. McCarthy noted could limit their generalizability.

For this effort, investigators used data from 4,496 participants in INTERSTROKE, an international case-control study of risk factors for a first acute stroke. About half of the participants had a history of stroke.

Using information collected from a survey of sleep habits, researchers found an elevated stroke risk in those who received less than 5 hours of sleep per night (odds ratio, 3.15; 95% confidence interval, 2.09-4.76) or more than 9 hours of sleep per night (OR, 2.67; 95% CI, 1.89-3.78), compared with those who slept 7 hours a night.

Participants who took unplanned naps or naps lasting an hour or more (OR, 2.46; 95% CI, 1.69-3.57) and participants who reported poor quality sleep (OR,1.52; 95% CI, 1.32-1.75) were also at an increased risk for stroke.

Symptoms of OSA were also strongly associated with increased stroke risk, including snoring (OR, 1.91; 95% CI, 1.62-2.24), snorting (OR, 2.64; 95% CI, 2.17-3.20), and breathing cessation (OR, 2.87; 95% CI, 2.28-2.60).

Stroke risk increased as the number of sleep disturbance symptoms rose, with the greatest risk in the 11% of participants who had five or more symptoms (OR, 5.38; 95% CI, 4.03-7.18).

“This study finds an association between a broad range of sleep impairment symptoms and stroke, and a graded association with increasing symptoms, in an international setting,” Dr. McCarthy said.

Researchers aren’t sure what’s driving the higher stroke risk among people with sleep disturbances. Although the study did control for potential confounders, it wasn’t designed to get at what’s driving the association.

“Sleep disturbance may also have a bi-directional relationship with many stroke risk factors; for example, sleep disturbance may be a symptom of disease and exacerbate disease,” Dr. McCarthy said. “Future interventional studies are required to determine the true direction of the relationship.”
 

A marker of stroke risk

Daniel Lackland, DrPH, professor of neurology at the Medical University of South Carolina, Charleston, said the findings provide additional evidence of the link between sleep and stroke risk.

“The results confirm sleep disorders as a potential marker and part of the risk profile,” he said.

Collecting information about sleep using a validated assessment tool is an important piece of clinical care, Dr. Lackland said, especially among patients with other stroke risk factors.

One limitation of the study was that data on sleep was collected only at one point, and participants were not followed over time to see if changes in sleep affected stroke risk.

“This is an important point and should be a focus for future studies, as it is critical in the design of interventions,” Dr. Lackland said.

The INTERSTROKE study is funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, Astra Zeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MERCK, Sharp and Dohme, Swedish Heart and Lung Foundation, U.K. Chest, and U.K. Heart and Stroke. Dr. McCarthy and Lackland report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Disordered sleep is associated with a significantly increased risk for stroke, new research shows.

Results of a large international study show stroke risk was more than three times higher in those who slept too little, more than twice as high in those who sleep too much, and two to three times higher in those with symptoms of severe obstructive sleep apnea.

The study also showed that the greater the number of sleep disorder symptoms, the greater the stroke risk. The 11% of study participants with five or more symptoms of disordered sleep had a fivefold increased risk for stroke.

Jupiterimages/Thinkstock

More symptoms, more risk

Previous research shows severe OSA doubles the risk of stroke and increases the chance of recurrent stroke. A 2019 study showed that people with insomnia had a small increased risk of stroke.

“Both snoring and extremes of sleep duration have been previously associated with an increased risk of stroke in observational research, but less is known about other symptoms of sleep impairment, with less consistent findings,” Dr. McCarthy said.

Prior studies have also generally come from a single geographic region, which Dr. McCarthy noted could limit their generalizability.

For this effort, investigators used data from 4,496 participants in INTERSTROKE, an international case-control study of risk factors for a first acute stroke. About half of the participants had a history of stroke.

Using information collected from a survey of sleep habits, researchers found an elevated stroke risk in those who received less than 5 hours of sleep per night (odds ratio, 3.15; 95% confidence interval, 2.09-4.76) or more than 9 hours of sleep per night (OR, 2.67; 95% CI, 1.89-3.78), compared with those who slept 7 hours a night.

Participants who took unplanned naps or naps lasting an hour or more (OR, 2.46; 95% CI, 1.69-3.57) and participants who reported poor quality sleep (OR,1.52; 95% CI, 1.32-1.75) were also at an increased risk for stroke.

Symptoms of OSA were also strongly associated with increased stroke risk, including snoring (OR, 1.91; 95% CI, 1.62-2.24), snorting (OR, 2.64; 95% CI, 2.17-3.20), and breathing cessation (OR, 2.87; 95% CI, 2.28-2.60).

Stroke risk increased as the number of sleep disturbance symptoms rose, with the greatest risk in the 11% of participants who had five or more symptoms (OR, 5.38; 95% CI, 4.03-7.18).

“This study finds an association between a broad range of sleep impairment symptoms and stroke, and a graded association with increasing symptoms, in an international setting,” Dr. McCarthy said.

Researchers aren’t sure what’s driving the higher stroke risk among people with sleep disturbances. Although the study did control for potential confounders, it wasn’t designed to get at what’s driving the association.

“Sleep disturbance may also have a bi-directional relationship with many stroke risk factors; for example, sleep disturbance may be a symptom of disease and exacerbate disease,” Dr. McCarthy said. “Future interventional studies are required to determine the true direction of the relationship.”
 

A marker of stroke risk

Daniel Lackland, DrPH, professor of neurology at the Medical University of South Carolina, Charleston, said the findings provide additional evidence of the link between sleep and stroke risk.

“The results confirm sleep disorders as a potential marker and part of the risk profile,” he said.

Collecting information about sleep using a validated assessment tool is an important piece of clinical care, Dr. Lackland said, especially among patients with other stroke risk factors.

One limitation of the study was that data on sleep was collected only at one point, and participants were not followed over time to see if changes in sleep affected stroke risk.

“This is an important point and should be a focus for future studies, as it is critical in the design of interventions,” Dr. Lackland said.

The INTERSTROKE study is funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, Astra Zeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MERCK, Sharp and Dohme, Swedish Heart and Lung Foundation, U.K. Chest, and U.K. Heart and Stroke. Dr. McCarthy and Lackland report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

THE CASE

An 85-year-old woman with hypertension presented to our hospital with a 10-month history of insomnia along with abdominal discomfort. Several months prior, the patient had undergone an esophagogastroduodenoscopy, the results of which were normal, and had received diagnoses of psychogenic insomnia and abdominal pain from her previous physician. At that time, she was prescribed eszopiclone, but her insomnia did not improve. She did not complain of any other gastrointestinal symptoms.

On examination at our hospital, the patient’s abdomen was soft and nontender. Laboratory results were unremarkable. Abdominal computed tomography was performed to exclude obvious malignancy and showed no remarkable findings.

Additional history taking and physical examination were performed. The patient reported that she could sleep for only about 2 hours per night due to persistent severe discomfort around the umbilicus, which she described as “itching.” The discomfort occurred along with an urge to move while she laid in a state of relaxed wakefulness. This discomfort occurred no matter what position she laid in and improved if she walked or tapped around the umbilicus for a while. She denied any unusual or uncomfortable sensations in her lower extremities.

Her symptoms were absent during the daytime and not related to diet. Furthermore, she did not have any symptoms of anxiety and/or depression; a detailed neurologic examination, including cognitive assessment and extrapyramidal system, yielded unremarkable findings. Additional laboratory tests showed a mild iron deficiency (ferritin, 52.6 µ g/L; iron, 10.7 µ mol/L) without anemia.

THE DIAGNOSIS

Given the patient’s presentation and clinical history, the differential diagnosis included restless abdomen (which is a spectrum or a phenotypic variant of restless legs syndrome [RLS]) and its mimics, which include fibromyalgia and gastrointestinal tract diseases. We considered the characteristic symptoms of this case (ie, irresistible symptoms, lengthy duration of symptoms, and sleep problems) to better support the diagnosis of restless abdomen than its mimics.¹ In particular, abdominal discomfort that led to insomnia was characteristic of restless abdomen, helping to pinpoint the diagnosis.

DISCUSSION

RLS is a common sensorimotor disorder that is characterized by an unpleasant urge to move the legs.² RLS may manifest as an idiopathic condition, or it can be secondary to medical conditions such as iron deficiency and Parkinson disease.^3,4 Because the unpleasant symptom is exacerbated in the evenings, patients with RLS frequently complain of sleep disturbance.

Cases of RLS-like sensory disorders, with symptoms involving sites other than the lower extremities (eg, arms, mouth, trunk, and genitals) recently have been reported.^5-7 Among them is restless abdomen, a rare disorder that manifests with a restless abdominal sensation and worsens the quality of sleep and life.⁶

Continue to: Restless abdomen meets all...

Restless abdomen meets all other diagnostic criteria for RLS except for the affected anatomy.^6,8 In most cases of restless abdomen, the uncomfortable sensation involves the abdomen, as well as other parts of the body (eg, legs and arms). Cases in which the symptoms are confined to the abdomen are rare, with only 7 reported to date. ^6,8-10 All of these cases have involved patients older than 40 years. ^6,8-10

Treatment is straightforward, but consider iron supplementation, as well

Because RLS or its variants degrade the quality of life and sleep in patients,^3,4 appropriate therapy must be initiated early. Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—specifically, pramipexole—has been used successfully in almost all cases.^6,8-10

Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—pramipexole—has been used successfully in almost all cases.

Previous clinical research has shown that patients with RLS have low levels of iron in the brain and may benefit from iron supplementation, even if they are not anemic.^3,4 Iron replacement is suggested for patients with RLS whose fasting serum ferritin level is ≤ 75 µg/L.⁴ It is not known to what extent iron deficiency is involved in the pathophysiology of restless abdomen, and further research is required to determine the optimal therapy for it.

Our patient was started on oral supplementation with sodium ferrous citrate (50 mg/d) based on an initial suspicion that iron deficiency was the cause of her restless abdomen. We also suggested that the patient undergo a fecal occult blood test or colonoscopy, but she declined because of her advanced age.

After 2 months of iron supplementation, the patient’s serum ferritin levels improved (100 µg/L) and her insomnia and abdominal discomfort improved a bit. However, 3 months after starting on the iron supplementation, her symptoms flared again.

Continue to: We then prescribed...

We then prescribed pramipexole 0.25 mg/d. The patient’s symptoms subsequently resolved, and she no longer experienced insomnia. This favorable response to dopamine agonist therapy supported the diagnosis of restless abdomen. The patient continues to take the pramipexole to prevent a relapse.

THE TAKEAWAY

Insomnia is a common presenting complaint in primary care and sleeping pills may be prescribed without adequate investigation of the cause. However, some patients may have serious underlying diseases.¹¹

Although restless abdomen is a disorder that causes severe sleep disturbance and impairs the patient’s quality of sleep and life, it is not widely recognized by clinicians and may be misdiagnosed. When recognized, insomnia due to restless abdomen can be relieved by a simple therapy: oral dopamine agonists. Therefore, primary care physicians should consider restless abdomen as a potential cause of insomnia with abdominal symptoms.

CORRESPONDENCE
Hirohisa Fujikawa, MD, Department of Medical Education Studies, International Research Center for Medical Education, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; [email protected]

THE CASE

An 85-year-old woman with hypertension presented to our hospital with a 10-month history of insomnia along with abdominal discomfort. Several months prior, the patient had undergone an esophagogastroduodenoscopy, the results of which were normal, and had received diagnoses of psychogenic insomnia and abdominal pain from her previous physician. At that time, she was prescribed eszopiclone, but her insomnia did not improve. She did not complain of any other gastrointestinal symptoms.

On examination at our hospital, the patient’s abdomen was soft and nontender. Laboratory results were unremarkable. Abdominal computed tomography was performed to exclude obvious malignancy and showed no remarkable findings.

Additional history taking and physical examination were performed. The patient reported that she could sleep for only about 2 hours per night due to persistent severe discomfort around the umbilicus, which she described as “itching.” The discomfort occurred along with an urge to move while she laid in a state of relaxed wakefulness. This discomfort occurred no matter what position she laid in and improved if she walked or tapped around the umbilicus for a while. She denied any unusual or uncomfortable sensations in her lower extremities.

Her symptoms were absent during the daytime and not related to diet. Furthermore, she did not have any symptoms of anxiety and/or depression; a detailed neurologic examination, including cognitive assessment and extrapyramidal system, yielded unremarkable findings. Additional laboratory tests showed a mild iron deficiency (ferritin, 52.6 µ g/L; iron, 10.7 µ mol/L) without anemia.

THE DIAGNOSIS

Given the patient’s presentation and clinical history, the differential diagnosis included restless abdomen (which is a spectrum or a phenotypic variant of restless legs syndrome [RLS]) and its mimics, which include fibromyalgia and gastrointestinal tract diseases. We considered the characteristic symptoms of this case (ie, irresistible symptoms, lengthy duration of symptoms, and sleep problems) to better support the diagnosis of restless abdomen than its mimics.¹ In particular, abdominal discomfort that led to insomnia was characteristic of restless abdomen, helping to pinpoint the diagnosis.

DISCUSSION

RLS is a common sensorimotor disorder that is characterized by an unpleasant urge to move the legs.² RLS may manifest as an idiopathic condition, or it can be secondary to medical conditions such as iron deficiency and Parkinson disease.^3,4 Because the unpleasant symptom is exacerbated in the evenings, patients with RLS frequently complain of sleep disturbance.

Cases of RLS-like sensory disorders, with symptoms involving sites other than the lower extremities (eg, arms, mouth, trunk, and genitals) recently have been reported.^5-7 Among them is restless abdomen, a rare disorder that manifests with a restless abdominal sensation and worsens the quality of sleep and life.⁶

Continue to: Restless abdomen meets all...

Restless abdomen meets all other diagnostic criteria for RLS except for the affected anatomy.^6,8 In most cases of restless abdomen, the uncomfortable sensation involves the abdomen, as well as other parts of the body (eg, legs and arms). Cases in which the symptoms are confined to the abdomen are rare, with only 7 reported to date. ^6,8-10 All of these cases have involved patients older than 40 years. ^6,8-10

Treatment is straightforward, but consider iron supplementation, as well

Because RLS or its variants degrade the quality of life and sleep in patients,^3,4 appropriate therapy must be initiated early. Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—specifically, pramipexole—has been used successfully in almost all cases.^6,8-10

Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—pramipexole—has been used successfully in almost all cases.

Previous clinical research has shown that patients with RLS have low levels of iron in the brain and may benefit from iron supplementation, even if they are not anemic.^3,4 Iron replacement is suggested for patients with RLS whose fasting serum ferritin level is ≤ 75 µg/L.⁴ It is not known to what extent iron deficiency is involved in the pathophysiology of restless abdomen, and further research is required to determine the optimal therapy for it.

Our patient was started on oral supplementation with sodium ferrous citrate (50 mg/d) based on an initial suspicion that iron deficiency was the cause of her restless abdomen. We also suggested that the patient undergo a fecal occult blood test or colonoscopy, but she declined because of her advanced age.

After 2 months of iron supplementation, the patient’s serum ferritin levels improved (100 µg/L) and her insomnia and abdominal discomfort improved a bit. However, 3 months after starting on the iron supplementation, her symptoms flared again.

Continue to: We then prescribed...

We then prescribed pramipexole 0.25 mg/d. The patient’s symptoms subsequently resolved, and she no longer experienced insomnia. This favorable response to dopamine agonist therapy supported the diagnosis of restless abdomen. The patient continues to take the pramipexole to prevent a relapse.

THE TAKEAWAY

Insomnia is a common presenting complaint in primary care and sleeping pills may be prescribed without adequate investigation of the cause. However, some patients may have serious underlying diseases.¹¹

Although restless abdomen is a disorder that causes severe sleep disturbance and impairs the patient’s quality of sleep and life, it is not widely recognized by clinicians and may be misdiagnosed. When recognized, insomnia due to restless abdomen can be relieved by a simple therapy: oral dopamine agonists. Therefore, primary care physicians should consider restless abdomen as a potential cause of insomnia with abdominal symptoms.

CORRESPONDENCE
Hirohisa Fujikawa, MD, Department of Medical Education Studies, International Research Center for Medical Education, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; [email protected]

THE CASE

An 85-year-old woman with hypertension presented to our hospital with a 10-month history of insomnia along with abdominal discomfort. Several months prior, the patient had undergone an esophagogastroduodenoscopy, the results of which were normal, and had received diagnoses of psychogenic insomnia and abdominal pain from her previous physician. At that time, she was prescribed eszopiclone, but her insomnia did not improve. She did not complain of any other gastrointestinal symptoms.

On examination at our hospital, the patient’s abdomen was soft and nontender. Laboratory results were unremarkable. Abdominal computed tomography was performed to exclude obvious malignancy and showed no remarkable findings.

Additional history taking and physical examination were performed. The patient reported that she could sleep for only about 2 hours per night due to persistent severe discomfort around the umbilicus, which she described as “itching.” The discomfort occurred along with an urge to move while she laid in a state of relaxed wakefulness. This discomfort occurred no matter what position she laid in and improved if she walked or tapped around the umbilicus for a while. She denied any unusual or uncomfortable sensations in her lower extremities.

Her symptoms were absent during the daytime and not related to diet. Furthermore, she did not have any symptoms of anxiety and/or depression; a detailed neurologic examination, including cognitive assessment and extrapyramidal system, yielded unremarkable findings. Additional laboratory tests showed a mild iron deficiency (ferritin, 52.6 µ g/L; iron, 10.7 µ mol/L) without anemia.

THE DIAGNOSIS

Given the patient’s presentation and clinical history, the differential diagnosis included restless abdomen (which is a spectrum or a phenotypic variant of restless legs syndrome [RLS]) and its mimics, which include fibromyalgia and gastrointestinal tract diseases. We considered the characteristic symptoms of this case (ie, irresistible symptoms, lengthy duration of symptoms, and sleep problems) to better support the diagnosis of restless abdomen than its mimics.¹ In particular, abdominal discomfort that led to insomnia was characteristic of restless abdomen, helping to pinpoint the diagnosis.

DISCUSSION

RLS is a common sensorimotor disorder that is characterized by an unpleasant urge to move the legs.² RLS may manifest as an idiopathic condition, or it can be secondary to medical conditions such as iron deficiency and Parkinson disease.^3,4 Because the unpleasant symptom is exacerbated in the evenings, patients with RLS frequently complain of sleep disturbance.

Cases of RLS-like sensory disorders, with symptoms involving sites other than the lower extremities (eg, arms, mouth, trunk, and genitals) recently have been reported.^5-7 Among them is restless abdomen, a rare disorder that manifests with a restless abdominal sensation and worsens the quality of sleep and life.⁶

Continue to: Restless abdomen meets all...

Restless abdomen meets all other diagnostic criteria for RLS except for the affected anatomy.^6,8 In most cases of restless abdomen, the uncomfortable sensation involves the abdomen, as well as other parts of the body (eg, legs and arms). Cases in which the symptoms are confined to the abdomen are rare, with only 7 reported to date. ^6,8-10 All of these cases have involved patients older than 40 years. ^6,8-10

Treatment is straightforward, but consider iron supplementation, as well

Because RLS or its variants degrade the quality of life and sleep in patients,^3,4 appropriate therapy must be initiated early. Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—specifically, pramipexole—has been used successfully in almost all cases.^6,8-10

Although the optimal treatment strategy for restless abdomen is yet to be established, an oral dopamine agonist—pramipexole—has been used successfully in almost all cases.

Previous clinical research has shown that patients with RLS have low levels of iron in the brain and may benefit from iron supplementation, even if they are not anemic.^3,4 Iron replacement is suggested for patients with RLS whose fasting serum ferritin level is ≤ 75 µg/L.⁴ It is not known to what extent iron deficiency is involved in the pathophysiology of restless abdomen, and further research is required to determine the optimal therapy for it.

Our patient was started on oral supplementation with sodium ferrous citrate (50 mg/d) based on an initial suspicion that iron deficiency was the cause of her restless abdomen. We also suggested that the patient undergo a fecal occult blood test or colonoscopy, but she declined because of her advanced age.

After 2 months of iron supplementation, the patient’s serum ferritin levels improved (100 µg/L) and her insomnia and abdominal discomfort improved a bit. However, 3 months after starting on the iron supplementation, her symptoms flared again.

Continue to: We then prescribed...

We then prescribed pramipexole 0.25 mg/d. The patient’s symptoms subsequently resolved, and she no longer experienced insomnia. This favorable response to dopamine agonist therapy supported the diagnosis of restless abdomen. The patient continues to take the pramipexole to prevent a relapse.

THE TAKEAWAY

Insomnia is a common presenting complaint in primary care and sleeping pills may be prescribed without adequate investigation of the cause. However, some patients may have serious underlying diseases.¹¹

Although restless abdomen is a disorder that causes severe sleep disturbance and impairs the patient’s quality of sleep and life, it is not widely recognized by clinicians and may be misdiagnosed. When recognized, insomnia due to restless abdomen can be relieved by a simple therapy: oral dopamine agonists. Therefore, primary care physicians should consider restless abdomen as a potential cause of insomnia with abdominal symptoms.

CORRESPONDENCE
Hirohisa Fujikawa, MD, Department of Medical Education Studies, International Research Center for Medical Education, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; [email protected]

PARIS – Listening to music via curated playlists at bedtime is effective for depression-related insomnia, although the depression itself is unaffected, new research suggests.

The Music to Improve Sleep Quality in Adults With Depression and Insomnia (MUSTAFI) trial randomly assigned more than 110 outpatients with depression to either a music intervention or a waiting list. Sleep quality and quality of life significantly improved after listening to music for half an hour at bedtime for 4 weeks.

“This is a low-cost, safe intervention that has no side effects and may easily be implemented in psychiatry” along with existing treatments, lead researcher Helle Nystrup Lund, PhD, unit for depression, Aalborg (Denmark) University Hospital, said in an interview.

The findings were presented at the European Psychiatric Association 2023 Congress, and recently published in the Nordic Journal of Psychiatry.
 

Difficult to resolve

The researchers noted that insomnia is common in patients with depression and is “difficult to resolve.”

They noted that, while music is commonly used as a sleep aid and a growing evidence base suggests it has positive effects, there have been few investigations into the effectiveness of music for patients with depression-related insomnia.

To fill this research gap, 112 outpatients with depression and comorbid insomnia who were receiving care at a single center were randomly assigned to either an intervention group or a wait list control group.

Participants in the intervention group listened to music for a minimum of 30 minutes at bedtime for 4 weeks. The music was delivered via the MusicStar app, which is available as a free download from the Apple and Android (Google Play) app stores. The app was developed by Dr. Lund and Lars Rye Bertelsen, a PhD student and music therapist at Aalborg University Hospital.

The app is designed as a multicolored star, with each arm of the star linking to a playlist lasting between 30 minutes and 1 hour. Each color of the star indicates a different tempo of music.

Blue playlists, Dr. Lund explained, offer the quietest music, green is more lively, and red is the most dynamic. Gray playlists linked to project-related soundtracks, such as summer rain.

Dr. Lund said organizing the playlists by stimuli and color code, instead of genre, allows users to regulate their level of arousal and makes the music choice intuitive and easy.

She said that the genres of music include New Age, folk, pop, classical, and film soundtracks, “but no hard rock.”

“There’s actually a quite large selection of music available, because studies show that individual choice is important, as are personal preferences,” she said, adding that the endless choices offered by streaming services can cause confusion.

“So we made curated playlists and designed them with well-known pieces, but also with newly composed music not associated with anything,” Dr. Lund said.

Participants were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Hamilton Depression Rating Scale, and two World Health Organization well-being questionnaires (WHO-5, WHOQOL-BREF), as well as actigraphy.

Results showed that, at 4 weeks, participants in the intervention group experienced significant improvements in sleep quality in comparison with control persons. The effect size for the PSQI was –2.1, and for quality of life on the WHO-5, the effect size was 8.4.

A subanalysis revealed that the length of nocturnal sleep in the intervention group increased by an average of 18 minutes during the study from a baseline of approximately 5 hours per night, said Dr. Lund.

However, there were no changes in actigraphy measurements and no significant improvements in HAMD-17 scores.

Dr. Lund said that, on the basis of these positive findings, music intervention as a sleep aid is now offered at Aalborg University Hospital to patients with depression-related insomnia.
 

Clinically meaningful?

Commenting on the findings, Gerald J. Haeffel, PhD, department of psychology, University of Notre Dame, South Bend, Ind., said that overall, the study showed there was a change in sleep-quality and quality of life scores of “about 10% in each.”

“This, on the surface, would seem to be a meaningful change,” although it is less clear whether it is “clinically meaningful.” Perhaps it is, “but it would be nice to have more information.”

It would be useful, he said, to “show the means for each group pre- to postintervention, along with standard deviations,” he added.

Dr. Haeffel added that on the basis of current results, it isn’t possible to determine whether individuals’ control over music choice is important.

“We have no idea if ‘choice’ or length of playlist had any causal role in the results. One would need to run a study with the same playlist, but in one group people have to listen to whatever song comes on versus another condition in which they get to choose a song off the same list,” he said.

He noted that his group conducted a study in which highly popular music that was chosen by individual participants was found to have a positive effect. Even so, he said, “we could not determine if it was ‘choice’ or ‘popularity’ that caused the positive effects of music.”

In addition, he said, the reason music has a positive effect on insomnia remains unclear.

“It is not because it helped with depression, and it’s not because it’s actually changing objective sleep parameters. It could be that it improves mood right before bed or helps distract people right before bed. At the same time, it could also just be a placebo effect,” said Dr. Haeffel.

In addition, he said, it’s important to note that the music intervention had no comparator, so “maybe just doing something different or getting to talk with researchers created the effect and has nothing to do with music.”

Overall, he believes that there are “not enough data” to use the sleep intervention that was employed in the current study “as primary intervention, but future work could show its usefulness as a supplement.”

Dr. Lund and Mr. Bertelsen reported ownership and sales of the MusicStar app. Dr. Haeffel reported no relevant financial relationships.

PARIS – Listening to music via curated playlists at bedtime is effective for depression-related insomnia, although the depression itself is unaffected, new research suggests.

The Music to Improve Sleep Quality in Adults With Depression and Insomnia (MUSTAFI) trial randomly assigned more than 110 outpatients with depression to either a music intervention or a waiting list. Sleep quality and quality of life significantly improved after listening to music for half an hour at bedtime for 4 weeks.

“This is a low-cost, safe intervention that has no side effects and may easily be implemented in psychiatry” along with existing treatments, lead researcher Helle Nystrup Lund, PhD, unit for depression, Aalborg (Denmark) University Hospital, said in an interview.

The findings were presented at the European Psychiatric Association 2023 Congress, and recently published in the Nordic Journal of Psychiatry.
 

Difficult to resolve

The researchers noted that insomnia is common in patients with depression and is “difficult to resolve.”

They noted that, while music is commonly used as a sleep aid and a growing evidence base suggests it has positive effects, there have been few investigations into the effectiveness of music for patients with depression-related insomnia.

To fill this research gap, 112 outpatients with depression and comorbid insomnia who were receiving care at a single center were randomly assigned to either an intervention group or a wait list control group.

Participants in the intervention group listened to music for a minimum of 30 minutes at bedtime for 4 weeks. The music was delivered via the MusicStar app, which is available as a free download from the Apple and Android (Google Play) app stores. The app was developed by Dr. Lund and Lars Rye Bertelsen, a PhD student and music therapist at Aalborg University Hospital.

The app is designed as a multicolored star, with each arm of the star linking to a playlist lasting between 30 minutes and 1 hour. Each color of the star indicates a different tempo of music.

Blue playlists, Dr. Lund explained, offer the quietest music, green is more lively, and red is the most dynamic. Gray playlists linked to project-related soundtracks, such as summer rain.

Dr. Lund said organizing the playlists by stimuli and color code, instead of genre, allows users to regulate their level of arousal and makes the music choice intuitive and easy.

She said that the genres of music include New Age, folk, pop, classical, and film soundtracks, “but no hard rock.”

“There’s actually a quite large selection of music available, because studies show that individual choice is important, as are personal preferences,” she said, adding that the endless choices offered by streaming services can cause confusion.

“So we made curated playlists and designed them with well-known pieces, but also with newly composed music not associated with anything,” Dr. Lund said.

Participants were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Hamilton Depression Rating Scale, and two World Health Organization well-being questionnaires (WHO-5, WHOQOL-BREF), as well as actigraphy.

Results showed that, at 4 weeks, participants in the intervention group experienced significant improvements in sleep quality in comparison with control persons. The effect size for the PSQI was –2.1, and for quality of life on the WHO-5, the effect size was 8.4.

A subanalysis revealed that the length of nocturnal sleep in the intervention group increased by an average of 18 minutes during the study from a baseline of approximately 5 hours per night, said Dr. Lund.

However, there were no changes in actigraphy measurements and no significant improvements in HAMD-17 scores.

Dr. Lund said that, on the basis of these positive findings, music intervention as a sleep aid is now offered at Aalborg University Hospital to patients with depression-related insomnia.
 

Clinically meaningful?

Commenting on the findings, Gerald J. Haeffel, PhD, department of psychology, University of Notre Dame, South Bend, Ind., said that overall, the study showed there was a change in sleep-quality and quality of life scores of “about 10% in each.”

“This, on the surface, would seem to be a meaningful change,” although it is less clear whether it is “clinically meaningful.” Perhaps it is, “but it would be nice to have more information.”

It would be useful, he said, to “show the means for each group pre- to postintervention, along with standard deviations,” he added.

Dr. Haeffel added that on the basis of current results, it isn’t possible to determine whether individuals’ control over music choice is important.

“We have no idea if ‘choice’ or length of playlist had any causal role in the results. One would need to run a study with the same playlist, but in one group people have to listen to whatever song comes on versus another condition in which they get to choose a song off the same list,” he said.

He noted that his group conducted a study in which highly popular music that was chosen by individual participants was found to have a positive effect. Even so, he said, “we could not determine if it was ‘choice’ or ‘popularity’ that caused the positive effects of music.”

In addition, he said, the reason music has a positive effect on insomnia remains unclear.

“It is not because it helped with depression, and it’s not because it’s actually changing objective sleep parameters. It could be that it improves mood right before bed or helps distract people right before bed. At the same time, it could also just be a placebo effect,” said Dr. Haeffel.

In addition, he said, it’s important to note that the music intervention had no comparator, so “maybe just doing something different or getting to talk with researchers created the effect and has nothing to do with music.”

Overall, he believes that there are “not enough data” to use the sleep intervention that was employed in the current study “as primary intervention, but future work could show its usefulness as a supplement.”

Dr. Lund and Mr. Bertelsen reported ownership and sales of the MusicStar app. Dr. Haeffel reported no relevant financial relationships.

PARIS – Listening to music via curated playlists at bedtime is effective for depression-related insomnia, although the depression itself is unaffected, new research suggests.

The Music to Improve Sleep Quality in Adults With Depression and Insomnia (MUSTAFI) trial randomly assigned more than 110 outpatients with depression to either a music intervention or a waiting list. Sleep quality and quality of life significantly improved after listening to music for half an hour at bedtime for 4 weeks.

“This is a low-cost, safe intervention that has no side effects and may easily be implemented in psychiatry” along with existing treatments, lead researcher Helle Nystrup Lund, PhD, unit for depression, Aalborg (Denmark) University Hospital, said in an interview.

The findings were presented at the European Psychiatric Association 2023 Congress, and recently published in the Nordic Journal of Psychiatry.
 

Difficult to resolve

The researchers noted that insomnia is common in patients with depression and is “difficult to resolve.”

They noted that, while music is commonly used as a sleep aid and a growing evidence base suggests it has positive effects, there have been few investigations into the effectiveness of music for patients with depression-related insomnia.

To fill this research gap, 112 outpatients with depression and comorbid insomnia who were receiving care at a single center were randomly assigned to either an intervention group or a wait list control group.

Participants in the intervention group listened to music for a minimum of 30 minutes at bedtime for 4 weeks. The music was delivered via the MusicStar app, which is available as a free download from the Apple and Android (Google Play) app stores. The app was developed by Dr. Lund and Lars Rye Bertelsen, a PhD student and music therapist at Aalborg University Hospital.

The app is designed as a multicolored star, with each arm of the star linking to a playlist lasting between 30 minutes and 1 hour. Each color of the star indicates a different tempo of music.

Blue playlists, Dr. Lund explained, offer the quietest music, green is more lively, and red is the most dynamic. Gray playlists linked to project-related soundtracks, such as summer rain.

Dr. Lund said organizing the playlists by stimuli and color code, instead of genre, allows users to regulate their level of arousal and makes the music choice intuitive and easy.

She said that the genres of music include New Age, folk, pop, classical, and film soundtracks, “but no hard rock.”

“There’s actually a quite large selection of music available, because studies show that individual choice is important, as are personal preferences,” she said, adding that the endless choices offered by streaming services can cause confusion.

“So we made curated playlists and designed them with well-known pieces, but also with newly composed music not associated with anything,” Dr. Lund said.

Participants were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Hamilton Depression Rating Scale, and two World Health Organization well-being questionnaires (WHO-5, WHOQOL-BREF), as well as actigraphy.

Results showed that, at 4 weeks, participants in the intervention group experienced significant improvements in sleep quality in comparison with control persons. The effect size for the PSQI was –2.1, and for quality of life on the WHO-5, the effect size was 8.4.

A subanalysis revealed that the length of nocturnal sleep in the intervention group increased by an average of 18 minutes during the study from a baseline of approximately 5 hours per night, said Dr. Lund.

However, there were no changes in actigraphy measurements and no significant improvements in HAMD-17 scores.

Dr. Lund said that, on the basis of these positive findings, music intervention as a sleep aid is now offered at Aalborg University Hospital to patients with depression-related insomnia.
 

Clinically meaningful?

Commenting on the findings, Gerald J. Haeffel, PhD, department of psychology, University of Notre Dame, South Bend, Ind., said that overall, the study showed there was a change in sleep-quality and quality of life scores of “about 10% in each.”

“This, on the surface, would seem to be a meaningful change,” although it is less clear whether it is “clinically meaningful.” Perhaps it is, “but it would be nice to have more information.”

It would be useful, he said, to “show the means for each group pre- to postintervention, along with standard deviations,” he added.

Dr. Haeffel added that on the basis of current results, it isn’t possible to determine whether individuals’ control over music choice is important.

“We have no idea if ‘choice’ or length of playlist had any causal role in the results. One would need to run a study with the same playlist, but in one group people have to listen to whatever song comes on versus another condition in which they get to choose a song off the same list,” he said.

He noted that his group conducted a study in which highly popular music that was chosen by individual participants was found to have a positive effect. Even so, he said, “we could not determine if it was ‘choice’ or ‘popularity’ that caused the positive effects of music.”

In addition, he said, the reason music has a positive effect on insomnia remains unclear.

“It is not because it helped with depression, and it’s not because it’s actually changing objective sleep parameters. It could be that it improves mood right before bed or helps distract people right before bed. At the same time, it could also just be a placebo effect,” said Dr. Haeffel.

In addition, he said, it’s important to note that the music intervention had no comparator, so “maybe just doing something different or getting to talk with researchers created the effect and has nothing to do with music.”

Overall, he believes that there are “not enough data” to use the sleep intervention that was employed in the current study “as primary intervention, but future work could show its usefulness as a supplement.”

Dr. Lund and Mr. Bertelsen reported ownership and sales of the MusicStar app. Dr. Haeffel reported no relevant financial relationships.

An intervention tailored for Black first-time mothers helped increase their infants’ sleep time, researchers have found, a notable result as many studies have shown Black infants get less sleep on average than White infants.

Less sleep has historically put Black children at higher risk for negative outcomes including obesity and poorer social-emotional functioning and cognitive development. These disparities persist into adulthood, the researchers note, as previous studies have shown.

Justin A. Lavner, PhD, with the department of psychology at the University of Georgia in Athens, led this post hoc secondary analysis of the Sleep SAAF (Strong African American Families) study, a randomized clinical trial of 234 participants comparing a responsive parenting (RP) intervention with a safety control group over the first 16 weeks post partum. The original analysis studied the effects of the intervention on rapid weight gain.

In the original analysis, the authors write that “From birth to 2, the prevalence of high weight for length (above the 95th percentile) is 25% higher among African American children compared to White children. From age 2 to 19, the rate of obesity is more than 50% higher among African American children compared to White children. Similar disparities persist into adulthood: rates of obesity are approximately 25% higher among African American adults compared to White adults.”

The differences in early rapid weight gain may be driving the disparities, the authors write.

Elements of the intervention

The intervention in the current analysis included materials delivered at the 3- and 8-week home visits focused on soothing and crying, feeding, and interactive play in the babies’ first months. Families were recruited from Augusta University Medical Center in Augusta, Ga., and had home visits at 1, 3, 8, and 16 weeks post partum.

Mothers got a packet of handouts and facilitators walked through the information with them. The measures involved hands-on activities, discussion, and videos, all tailored for Black families, the authors state.

Mothers were taught about responding appropriately at night when their baby cries, including giving the baby a couple of minutes to fall back to sleep independently and by using calming messages, such as shushing or white noise, before picking the baby up.
 

Babies learn to fall asleep on their own

They also learned to put infants to bed early (ideally by 8 p.m.) so the babies would be calm but awake and could learn to fall asleep on their own.

The control group’s guidance was matched for intensity and session length but focused on sleep and home safety, such as reducing the risk of sudden infant death syndrome (SIDS), keeping the baby’s sleep area close to, but away from, the mother’s bed, and preventing shaken baby syndrome.

In both groups, the 3-week visit session lasted about 90-120 minutes and the 8-week visit lasted about 45-60 minutes.
 

Longer sleep with the intervention

A total of 212 Black mothers, average age 22.7, were randomized – 108 to the RP group and 104 to the control group. Answers on questionnaires were analyzed and at 16 weeks post partum, infants in the RP group (relative to controls) had:

• Longer reported nighttime sleep (mean difference, 40 minutes [95% confidence interval, 3-77]).
• Longer total sleep duration (mean difference, 73 minutes [95% CI, 14-131]).
• Fewer nighttime wakings (mean difference, −0.4 wakings [95% CI, −0.6 to −0.1]).
• Greater likelihood of meeting guidelines of at least 12 hours of sleep per day (risk ratio, 1.4 [95% CI, 1.1 to 1.8]) than controls.

Findings were published in JAMA Network Open.

Additionally, mothers in the RP group more frequently reported they engaged in practices such as letting babies have a few minutes to fall back to sleep on their own (RR, 1.6 [95% CI, 1.0-2.6]) and being less likely to feed their infant just before the baby’s bedtime (RR, 0.5 [95% CI, 0.3-0.8]).

In an accompanying invited commentary, Sarah M. Honaker, PhD, department of pediatrics, Indiana University, Indianapolis, and Alicia Chung, EdD, Center for Early Childhood Health and Development at New York University, write that though the added average sleep duration is one of the most significant findings, there is a possibility of desirability bias because it was reported by the mothers after specific guidance by the facilitators.

“Nonetheless,” the editorialists write, “even if the true effect were half as small, this additional sleep duration could yield notable benefits in infant development if the effect persisted over time. The difference in night wakings between the intervention and control groups (1.8 vs 1.5 per night) at 16 weeks postpartum was statistically significant, though it is unclear whether this difference is clinically meaningful to families.”

They note that it is unclear from the study how the intervention was culturally adapted and how the adaptation might have affected outcomes.

Sleep intervention trials have focused on White families

The editorialists write that much is known about the benefits of behavioral sleep intervention in controlled trials and general population settings, and no adverse effects on infant attachment or cortisol levels have been linked to the interventions.

However, they add, “Unfortunately, this substantial progress in our understanding of infant BSI [behavioral sleep intervention] comes with a caveat, in that most previous studies have been performed with White families from mid-to-high socioeconomic backgrounds.”

Dr. Honaker and Dr. Chung write, “[I]t is important to note that much work remains to examine the acceptability, feasibility, and efficacy of infant BSI in other groups that have been historically marginalized.”

Dr. Lavner and colleagues point out that before their study, there had been little emphasis on interventions to encourage better sleep in general for Black infants, “as most early sleep interventions for this population have focused on SIDS prevention.”

The study by Dr. Lavner et al. was funded by the National Institutes of Health, a Harrington Faculty Fellowship from the University of Texas, and an award from the Penn State Clinical and Translational Sciences Institute supported by the National Center for Advancing Translational Sciences. Editorialist Dr. Honaker reported receiving grants from Nationwide Children’s Hospital (parent grant, Centers for Disease Control and Prevention) to evaluate the acceptability of infant behavioral sleep intervention in Black families.

An intervention tailored for Black first-time mothers helped increase their infants’ sleep time, researchers have found, a notable result as many studies have shown Black infants get less sleep on average than White infants.

Less sleep has historically put Black children at higher risk for negative outcomes including obesity and poorer social-emotional functioning and cognitive development. These disparities persist into adulthood, the researchers note, as previous studies have shown.

Justin A. Lavner, PhD, with the department of psychology at the University of Georgia in Athens, led this post hoc secondary analysis of the Sleep SAAF (Strong African American Families) study, a randomized clinical trial of 234 participants comparing a responsive parenting (RP) intervention with a safety control group over the first 16 weeks post partum. The original analysis studied the effects of the intervention on rapid weight gain.

In the original analysis, the authors write that “From birth to 2, the prevalence of high weight for length (above the 95th percentile) is 25% higher among African American children compared to White children. From age 2 to 19, the rate of obesity is more than 50% higher among African American children compared to White children. Similar disparities persist into adulthood: rates of obesity are approximately 25% higher among African American adults compared to White adults.”

The differences in early rapid weight gain may be driving the disparities, the authors write.

Elements of the intervention

The intervention in the current analysis included materials delivered at the 3- and 8-week home visits focused on soothing and crying, feeding, and interactive play in the babies’ first months. Families were recruited from Augusta University Medical Center in Augusta, Ga., and had home visits at 1, 3, 8, and 16 weeks post partum.

Mothers got a packet of handouts and facilitators walked through the information with them. The measures involved hands-on activities, discussion, and videos, all tailored for Black families, the authors state.

Mothers were taught about responding appropriately at night when their baby cries, including giving the baby a couple of minutes to fall back to sleep independently and by using calming messages, such as shushing or white noise, before picking the baby up.
 

Babies learn to fall asleep on their own

They also learned to put infants to bed early (ideally by 8 p.m.) so the babies would be calm but awake and could learn to fall asleep on their own.

The control group’s guidance was matched for intensity and session length but focused on sleep and home safety, such as reducing the risk of sudden infant death syndrome (SIDS), keeping the baby’s sleep area close to, but away from, the mother’s bed, and preventing shaken baby syndrome.

In both groups, the 3-week visit session lasted about 90-120 minutes and the 8-week visit lasted about 45-60 minutes.
 

Longer sleep with the intervention

A total of 212 Black mothers, average age 22.7, were randomized – 108 to the RP group and 104 to the control group. Answers on questionnaires were analyzed and at 16 weeks post partum, infants in the RP group (relative to controls) had:

• Longer reported nighttime sleep (mean difference, 40 minutes [95% confidence interval, 3-77]).
• Longer total sleep duration (mean difference, 73 minutes [95% CI, 14-131]).
• Fewer nighttime wakings (mean difference, −0.4 wakings [95% CI, −0.6 to −0.1]).
• Greater likelihood of meeting guidelines of at least 12 hours of sleep per day (risk ratio, 1.4 [95% CI, 1.1 to 1.8]) than controls.

Findings were published in JAMA Network Open.

Additionally, mothers in the RP group more frequently reported they engaged in practices such as letting babies have a few minutes to fall back to sleep on their own (RR, 1.6 [95% CI, 1.0-2.6]) and being less likely to feed their infant just before the baby’s bedtime (RR, 0.5 [95% CI, 0.3-0.8]).

In an accompanying invited commentary, Sarah M. Honaker, PhD, department of pediatrics, Indiana University, Indianapolis, and Alicia Chung, EdD, Center for Early Childhood Health and Development at New York University, write that though the added average sleep duration is one of the most significant findings, there is a possibility of desirability bias because it was reported by the mothers after specific guidance by the facilitators.

“Nonetheless,” the editorialists write, “even if the true effect were half as small, this additional sleep duration could yield notable benefits in infant development if the effect persisted over time. The difference in night wakings between the intervention and control groups (1.8 vs 1.5 per night) at 16 weeks postpartum was statistically significant, though it is unclear whether this difference is clinically meaningful to families.”

They note that it is unclear from the study how the intervention was culturally adapted and how the adaptation might have affected outcomes.

Sleep intervention trials have focused on White families

The editorialists write that much is known about the benefits of behavioral sleep intervention in controlled trials and general population settings, and no adverse effects on infant attachment or cortisol levels have been linked to the interventions.

However, they add, “Unfortunately, this substantial progress in our understanding of infant BSI [behavioral sleep intervention] comes with a caveat, in that most previous studies have been performed with White families from mid-to-high socioeconomic backgrounds.”

Dr. Honaker and Dr. Chung write, “[I]t is important to note that much work remains to examine the acceptability, feasibility, and efficacy of infant BSI in other groups that have been historically marginalized.”

Dr. Lavner and colleagues point out that before their study, there had been little emphasis on interventions to encourage better sleep in general for Black infants, “as most early sleep interventions for this population have focused on SIDS prevention.”

The study by Dr. Lavner et al. was funded by the National Institutes of Health, a Harrington Faculty Fellowship from the University of Texas, and an award from the Penn State Clinical and Translational Sciences Institute supported by the National Center for Advancing Translational Sciences. Editorialist Dr. Honaker reported receiving grants from Nationwide Children’s Hospital (parent grant, Centers for Disease Control and Prevention) to evaluate the acceptability of infant behavioral sleep intervention in Black families.

An intervention tailored for Black first-time mothers helped increase their infants’ sleep time, researchers have found, a notable result as many studies have shown Black infants get less sleep on average than White infants.

Less sleep has historically put Black children at higher risk for negative outcomes including obesity and poorer social-emotional functioning and cognitive development. These disparities persist into adulthood, the researchers note, as previous studies have shown.

Justin A. Lavner, PhD, with the department of psychology at the University of Georgia in Athens, led this post hoc secondary analysis of the Sleep SAAF (Strong African American Families) study, a randomized clinical trial of 234 participants comparing a responsive parenting (RP) intervention with a safety control group over the first 16 weeks post partum. The original analysis studied the effects of the intervention on rapid weight gain.

In the original analysis, the authors write that “From birth to 2, the prevalence of high weight for length (above the 95th percentile) is 25% higher among African American children compared to White children. From age 2 to 19, the rate of obesity is more than 50% higher among African American children compared to White children. Similar disparities persist into adulthood: rates of obesity are approximately 25% higher among African American adults compared to White adults.”

The differences in early rapid weight gain may be driving the disparities, the authors write.

Elements of the intervention

The intervention in the current analysis included materials delivered at the 3- and 8-week home visits focused on soothing and crying, feeding, and interactive play in the babies’ first months. Families were recruited from Augusta University Medical Center in Augusta, Ga., and had home visits at 1, 3, 8, and 16 weeks post partum.

Mothers got a packet of handouts and facilitators walked through the information with them. The measures involved hands-on activities, discussion, and videos, all tailored for Black families, the authors state.

Mothers were taught about responding appropriately at night when their baby cries, including giving the baby a couple of minutes to fall back to sleep independently and by using calming messages, such as shushing or white noise, before picking the baby up.
 

Babies learn to fall asleep on their own

They also learned to put infants to bed early (ideally by 8 p.m.) so the babies would be calm but awake and could learn to fall asleep on their own.

The control group’s guidance was matched for intensity and session length but focused on sleep and home safety, such as reducing the risk of sudden infant death syndrome (SIDS), keeping the baby’s sleep area close to, but away from, the mother’s bed, and preventing shaken baby syndrome.

In both groups, the 3-week visit session lasted about 90-120 minutes and the 8-week visit lasted about 45-60 minutes.
 

Longer sleep with the intervention

A total of 212 Black mothers, average age 22.7, were randomized – 108 to the RP group and 104 to the control group. Answers on questionnaires were analyzed and at 16 weeks post partum, infants in the RP group (relative to controls) had:

• Longer reported nighttime sleep (mean difference, 40 minutes [95% confidence interval, 3-77]).
• Longer total sleep duration (mean difference, 73 minutes [95% CI, 14-131]).
• Fewer nighttime wakings (mean difference, −0.4 wakings [95% CI, −0.6 to −0.1]).
• Greater likelihood of meeting guidelines of at least 12 hours of sleep per day (risk ratio, 1.4 [95% CI, 1.1 to 1.8]) than controls.

Findings were published in JAMA Network Open.

Additionally, mothers in the RP group more frequently reported they engaged in practices such as letting babies have a few minutes to fall back to sleep on their own (RR, 1.6 [95% CI, 1.0-2.6]) and being less likely to feed their infant just before the baby’s bedtime (RR, 0.5 [95% CI, 0.3-0.8]).

In an accompanying invited commentary, Sarah M. Honaker, PhD, department of pediatrics, Indiana University, Indianapolis, and Alicia Chung, EdD, Center for Early Childhood Health and Development at New York University, write that though the added average sleep duration is one of the most significant findings, there is a possibility of desirability bias because it was reported by the mothers after specific guidance by the facilitators.

“Nonetheless,” the editorialists write, “even if the true effect were half as small, this additional sleep duration could yield notable benefits in infant development if the effect persisted over time. The difference in night wakings between the intervention and control groups (1.8 vs 1.5 per night) at 16 weeks postpartum was statistically significant, though it is unclear whether this difference is clinically meaningful to families.”

They note that it is unclear from the study how the intervention was culturally adapted and how the adaptation might have affected outcomes.

Sleep intervention trials have focused on White families

The editorialists write that much is known about the benefits of behavioral sleep intervention in controlled trials and general population settings, and no adverse effects on infant attachment or cortisol levels have been linked to the interventions.

However, they add, “Unfortunately, this substantial progress in our understanding of infant BSI [behavioral sleep intervention] comes with a caveat, in that most previous studies have been performed with White families from mid-to-high socioeconomic backgrounds.”

Dr. Honaker and Dr. Chung write, “[I]t is important to note that much work remains to examine the acceptability, feasibility, and efficacy of infant BSI in other groups that have been historically marginalized.”

Dr. Lavner and colleagues point out that before their study, there had been little emphasis on interventions to encourage better sleep in general for Black infants, “as most early sleep interventions for this population have focused on SIDS prevention.”

The study by Dr. Lavner et al. was funded by the National Institutes of Health, a Harrington Faculty Fellowship from the University of Texas, and an award from the Penn State Clinical and Translational Sciences Institute supported by the National Center for Advancing Translational Sciences. Editorialist Dr. Honaker reported receiving grants from Nationwide Children’s Hospital (parent grant, Centers for Disease Control and Prevention) to evaluate the acceptability of infant behavioral sleep intervention in Black families.

The sleep aid melatonin is associated with a reduced risk of self-harm in adolescents with psychiatric disorders, new research suggests. However, at least one expert has some concerns about the strength of the evidence.

The results suggest improving sleep hygiene in this population may reduce self-injury, study investigator Sarah E. Bergen, PhD, associate professor, department of medical epidemiology and biostatistics, Karolinska Institute, Stockholm, said in an interview.

In addition, she noted, for “pediatric patients who are experiencing sleep problems, melatonin is a safe and effective way to help them.”

Dr. Bergen believes clinicians should recommend melatonin to all teens because “there’s little harm that could come from it and possibly a lot of benefit.”

The findings were published online in the Journal of Child Psychology and Psychiatry.
 

Few treatments available

Research shows sleep disorders like insomnia are common in youth, particularly among those with psychiatric disorders. Sleep disorders can significantly affect daytime functioning, cognition, emotional regulation, and behavior, and can be a risk factor for unintentional injuries such as falls and vehicular accidents, as well as for intentional self-harm.

The lifetime prevalence of self-harm in youth is estimated to be 17%, but this varies across study designs. There are few treatments for self-harm in youth, although psychosocial treatments appear promising.

Melatonin is a naturally occurring hormone secreted primarily by the pineal gland in response to darkness. It helps promote and maintain the normal sleep-wake cycle and is involved in other biological functions.

In Sweden, melatonin is the most commonly prescribed drug for sleep disturbances in children and adolescents. Prior to 2020, during the course of the study, it was only available by prescription.

The study, which used linked national databases, included 25,575 children and adolescents, 58.2% of them male, who initiated a melatonin treatment between the ages of 6 and 18 years.

Researchers estimated the risks of self-harm, including poisoning (57%) and cutting (34%). The fact that poisoning was more common than cutting was somewhat surprising, said Dr. Bergen. “I would have thought the opposite would be true; that cutting was more prevalent.”

The study examined the risk of self-harm in individual participants by comparing the last unmedicated month with the 12 months after initiating melatonin treatment. In this way, they accounted for potential confounders such as genetics, sleep disorder severity, and psychiatric disorders.

The median age at first melatonin prescription was 13 years for males and 15 years for females.

While there were no statistically significant changes in relative risk for body injuries, falls, and transport accidents, the relative risk for self-injury was statistically significantly lower during the months following melatonin treatment initiation.

The incidence rate ratio in the month following treatment was 0.58 (95% confidence interval, 0.46-0.73) for self-harm and 0.59 (95% CI, 0.45-0.78) for poisoning.
 

Higher risks in females

The relative risk of self-harm was higher in females than males. This, said Dr. Bergen, is possibly because self-harm is more common in adolescence than in childhood. Female study participants were older than their male counterparts.

Melatonin may help male teens, too, she said. “It’s just that the problem is not that great in males to begin with, so a decrease is not very dramatic after melatonin initiation.”

About 87.2% of participants treated with melatonin were diagnosed with at least one psychiatric disorder. Attention-deficit hyperactivity disorder, the most common comorbidity, was diagnosed in more than 50% of new melatonin users. This isn’t surprising, because sleep disturbances are associated with this psychiatric condition and are frequent side effects of ADHD medications.

After ADHD, anxiety and depression were the next most common psychiatric disorders among study subjects. The analysis found risks for self-harm and poisoning were largely driven by patients suffering from one or both of these disorders, particularly among females.

The IRR in the month following melatonin treatment initiation was 0.46 (95% CI, 0.27-0.76] among adolescent females with psychiatric disorders, after excluding antidepressant users.

Melatonin may reduce the risk of self-harm by treating sleep problems related to psychiatric comorbidities, especially anxiety and depression. It could also decrease pain sensitivity experienced by adolescents who self-harm.

Other factors could play a role in treating sleep problems and/or preventing self-harm in these patients. For example, increased clinician awareness and monitoring, behavioral interventions, a placebo effect, and concurrent use of other medications.

When researchers ran an analysis that excluded individuals taking an antidepressant, “surprisingly, there wasn’t much difference,” said Dr. Bergen. “We thought antidepressants might be causing some of the effect we observed, but when we removed antidepressant users, we saw a very similar pattern of intentional self-harm rates following melatonin use, which suggests melatonin is causal, but we can’t prove that.”

Other sleep medications such as sedatives could also affect self-harm rates by improving sleep. However, these are not typically prescribed to children because of their side effects and overdose potential, said Dr. Bergen.

“Melatonin is extremely safe and side effects are rare; it’s impossible to overdose, and people really can’t hurt themselves with it.”
 

More research needed

Adrian Jacques Ambrose, MD, medical director, Columbia University Irving Medical Center, and assistant professor of psychiatry, Columbia University, New York, pointed out some evidence in the study is relatively weak.

“When the authors separated out the on- and off-melatonin groups, it looks like there wasn’t a statistically significant difference [in IRRs] between the two groups – for example, in any injury, self-harm, or poisoning – and this weakens their argument that melatonin is associated with self-harm and poisoning.”

Given the current youth mental health crisis, more research “would absolutely be indicated” to better explore possible additional variables, said Dr. Ambrose.

“For example, some additional follow-up studies may add on covariates in conjunction with melatonin usage, such as the number of medical appointments, the presence of psychotherapeutic interventions, dosage of melatonin, or even the sleepiness scale, to evaluate whether the symptoms of sleep disturbances are more directly correlated with the self-harm behaviors.”

The study was supported by the European Union’s Horizon 2020 Research and Innovation Programme. Dr. Bergen and Dr. Ambrose report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The sleep aid melatonin is associated with a reduced risk of self-harm in adolescents with psychiatric disorders, new research suggests. However, at least one expert has some concerns about the strength of the evidence.

The results suggest improving sleep hygiene in this population may reduce self-injury, study investigator Sarah E. Bergen, PhD, associate professor, department of medical epidemiology and biostatistics, Karolinska Institute, Stockholm, said in an interview.

In addition, she noted, for “pediatric patients who are experiencing sleep problems, melatonin is a safe and effective way to help them.”

Dr. Bergen believes clinicians should recommend melatonin to all teens because “there’s little harm that could come from it and possibly a lot of benefit.”

The findings were published online in the Journal of Child Psychology and Psychiatry.
 

Few treatments available

Research shows sleep disorders like insomnia are common in youth, particularly among those with psychiatric disorders. Sleep disorders can significantly affect daytime functioning, cognition, emotional regulation, and behavior, and can be a risk factor for unintentional injuries such as falls and vehicular accidents, as well as for intentional self-harm.

The lifetime prevalence of self-harm in youth is estimated to be 17%, but this varies across study designs. There are few treatments for self-harm in youth, although psychosocial treatments appear promising.

Melatonin is a naturally occurring hormone secreted primarily by the pineal gland in response to darkness. It helps promote and maintain the normal sleep-wake cycle and is involved in other biological functions.

In Sweden, melatonin is the most commonly prescribed drug for sleep disturbances in children and adolescents. Prior to 2020, during the course of the study, it was only available by prescription.

The study, which used linked national databases, included 25,575 children and adolescents, 58.2% of them male, who initiated a melatonin treatment between the ages of 6 and 18 years.

Researchers estimated the risks of self-harm, including poisoning (57%) and cutting (34%). The fact that poisoning was more common than cutting was somewhat surprising, said Dr. Bergen. “I would have thought the opposite would be true; that cutting was more prevalent.”

The study examined the risk of self-harm in individual participants by comparing the last unmedicated month with the 12 months after initiating melatonin treatment. In this way, they accounted for potential confounders such as genetics, sleep disorder severity, and psychiatric disorders.

The median age at first melatonin prescription was 13 years for males and 15 years for females.

While there were no statistically significant changes in relative risk for body injuries, falls, and transport accidents, the relative risk for self-injury was statistically significantly lower during the months following melatonin treatment initiation.

The incidence rate ratio in the month following treatment was 0.58 (95% confidence interval, 0.46-0.73) for self-harm and 0.59 (95% CI, 0.45-0.78) for poisoning.
 

Higher risks in females

The relative risk of self-harm was higher in females than males. This, said Dr. Bergen, is possibly because self-harm is more common in adolescence than in childhood. Female study participants were older than their male counterparts.

Melatonin may help male teens, too, she said. “It’s just that the problem is not that great in males to begin with, so a decrease is not very dramatic after melatonin initiation.”

About 87.2% of participants treated with melatonin were diagnosed with at least one psychiatric disorder. Attention-deficit hyperactivity disorder, the most common comorbidity, was diagnosed in more than 50% of new melatonin users. This isn’t surprising, because sleep disturbances are associated with this psychiatric condition and are frequent side effects of ADHD medications.

After ADHD, anxiety and depression were the next most common psychiatric disorders among study subjects. The analysis found risks for self-harm and poisoning were largely driven by patients suffering from one or both of these disorders, particularly among females.

The IRR in the month following melatonin treatment initiation was 0.46 (95% CI, 0.27-0.76] among adolescent females with psychiatric disorders, after excluding antidepressant users.

Melatonin may reduce the risk of self-harm by treating sleep problems related to psychiatric comorbidities, especially anxiety and depression. It could also decrease pain sensitivity experienced by adolescents who self-harm.

Other factors could play a role in treating sleep problems and/or preventing self-harm in these patients. For example, increased clinician awareness and monitoring, behavioral interventions, a placebo effect, and concurrent use of other medications.

When researchers ran an analysis that excluded individuals taking an antidepressant, “surprisingly, there wasn’t much difference,” said Dr. Bergen. “We thought antidepressants might be causing some of the effect we observed, but when we removed antidepressant users, we saw a very similar pattern of intentional self-harm rates following melatonin use, which suggests melatonin is causal, but we can’t prove that.”

Other sleep medications such as sedatives could also affect self-harm rates by improving sleep. However, these are not typically prescribed to children because of their side effects and overdose potential, said Dr. Bergen.

“Melatonin is extremely safe and side effects are rare; it’s impossible to overdose, and people really can’t hurt themselves with it.”
 

More research needed

Adrian Jacques Ambrose, MD, medical director, Columbia University Irving Medical Center, and assistant professor of psychiatry, Columbia University, New York, pointed out some evidence in the study is relatively weak.

“When the authors separated out the on- and off-melatonin groups, it looks like there wasn’t a statistically significant difference [in IRRs] between the two groups – for example, in any injury, self-harm, or poisoning – and this weakens their argument that melatonin is associated with self-harm and poisoning.”

Given the current youth mental health crisis, more research “would absolutely be indicated” to better explore possible additional variables, said Dr. Ambrose.

“For example, some additional follow-up studies may add on covariates in conjunction with melatonin usage, such as the number of medical appointments, the presence of psychotherapeutic interventions, dosage of melatonin, or even the sleepiness scale, to evaluate whether the symptoms of sleep disturbances are more directly correlated with the self-harm behaviors.”

The study was supported by the European Union’s Horizon 2020 Research and Innovation Programme. Dr. Bergen and Dr. Ambrose report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The sleep aid melatonin is associated with a reduced risk of self-harm in adolescents with psychiatric disorders, new research suggests. However, at least one expert has some concerns about the strength of the evidence.

The results suggest improving sleep hygiene in this population may reduce self-injury, study investigator Sarah E. Bergen, PhD, associate professor, department of medical epidemiology and biostatistics, Karolinska Institute, Stockholm, said in an interview.

In addition, she noted, for “pediatric patients who are experiencing sleep problems, melatonin is a safe and effective way to help them.”

Dr. Bergen believes clinicians should recommend melatonin to all teens because “there’s little harm that could come from it and possibly a lot of benefit.”

The findings were published online in the Journal of Child Psychology and Psychiatry.
 

Few treatments available

Research shows sleep disorders like insomnia are common in youth, particularly among those with psychiatric disorders. Sleep disorders can significantly affect daytime functioning, cognition, emotional regulation, and behavior, and can be a risk factor for unintentional injuries such as falls and vehicular accidents, as well as for intentional self-harm.

The lifetime prevalence of self-harm in youth is estimated to be 17%, but this varies across study designs. There are few treatments for self-harm in youth, although psychosocial treatments appear promising.

Melatonin is a naturally occurring hormone secreted primarily by the pineal gland in response to darkness. It helps promote and maintain the normal sleep-wake cycle and is involved in other biological functions.

In Sweden, melatonin is the most commonly prescribed drug for sleep disturbances in children and adolescents. Prior to 2020, during the course of the study, it was only available by prescription.

The study, which used linked national databases, included 25,575 children and adolescents, 58.2% of them male, who initiated a melatonin treatment between the ages of 6 and 18 years.

Researchers estimated the risks of self-harm, including poisoning (57%) and cutting (34%). The fact that poisoning was more common than cutting was somewhat surprising, said Dr. Bergen. “I would have thought the opposite would be true; that cutting was more prevalent.”

The study examined the risk of self-harm in individual participants by comparing the last unmedicated month with the 12 months after initiating melatonin treatment. In this way, they accounted for potential confounders such as genetics, sleep disorder severity, and psychiatric disorders.

The median age at first melatonin prescription was 13 years for males and 15 years for females.

While there were no statistically significant changes in relative risk for body injuries, falls, and transport accidents, the relative risk for self-injury was statistically significantly lower during the months following melatonin treatment initiation.

The incidence rate ratio in the month following treatment was 0.58 (95% confidence interval, 0.46-0.73) for self-harm and 0.59 (95% CI, 0.45-0.78) for poisoning.
 

Higher risks in females

The relative risk of self-harm was higher in females than males. This, said Dr. Bergen, is possibly because self-harm is more common in adolescence than in childhood. Female study participants were older than their male counterparts.

Melatonin may help male teens, too, she said. “It’s just that the problem is not that great in males to begin with, so a decrease is not very dramatic after melatonin initiation.”

About 87.2% of participants treated with melatonin were diagnosed with at least one psychiatric disorder. Attention-deficit hyperactivity disorder, the most common comorbidity, was diagnosed in more than 50% of new melatonin users. This isn’t surprising, because sleep disturbances are associated with this psychiatric condition and are frequent side effects of ADHD medications.

After ADHD, anxiety and depression were the next most common psychiatric disorders among study subjects. The analysis found risks for self-harm and poisoning were largely driven by patients suffering from one or both of these disorders, particularly among females.

The IRR in the month following melatonin treatment initiation was 0.46 (95% CI, 0.27-0.76] among adolescent females with psychiatric disorders, after excluding antidepressant users.

Melatonin may reduce the risk of self-harm by treating sleep problems related to psychiatric comorbidities, especially anxiety and depression. It could also decrease pain sensitivity experienced by adolescents who self-harm.

Other factors could play a role in treating sleep problems and/or preventing self-harm in these patients. For example, increased clinician awareness and monitoring, behavioral interventions, a placebo effect, and concurrent use of other medications.

When researchers ran an analysis that excluded individuals taking an antidepressant, “surprisingly, there wasn’t much difference,” said Dr. Bergen. “We thought antidepressants might be causing some of the effect we observed, but when we removed antidepressant users, we saw a very similar pattern of intentional self-harm rates following melatonin use, which suggests melatonin is causal, but we can’t prove that.”

Other sleep medications such as sedatives could also affect self-harm rates by improving sleep. However, these are not typically prescribed to children because of their side effects and overdose potential, said Dr. Bergen.

“Melatonin is extremely safe and side effects are rare; it’s impossible to overdose, and people really can’t hurt themselves with it.”
 

More research needed

Adrian Jacques Ambrose, MD, medical director, Columbia University Irving Medical Center, and assistant professor of psychiatry, Columbia University, New York, pointed out some evidence in the study is relatively weak.

“When the authors separated out the on- and off-melatonin groups, it looks like there wasn’t a statistically significant difference [in IRRs] between the two groups – for example, in any injury, self-harm, or poisoning – and this weakens their argument that melatonin is associated with self-harm and poisoning.”

Given the current youth mental health crisis, more research “would absolutely be indicated” to better explore possible additional variables, said Dr. Ambrose.

“For example, some additional follow-up studies may add on covariates in conjunction with melatonin usage, such as the number of medical appointments, the presence of psychotherapeutic interventions, dosage of melatonin, or even the sleepiness scale, to evaluate whether the symptoms of sleep disturbances are more directly correlated with the self-harm behaviors.”

The study was supported by the European Union’s Horizon 2020 Research and Innovation Programme. Dr. Bergen and Dr. Ambrose report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

DENVER – The relationship between nighttime knee pain from osteoarthritis and sleep disturbances is more complex than a simple association, according to new research presented at the Osteoarthritis Research Society International 2023 World Congress.

The findings suggested that the association between knee OA pain and sleep problems was also linked to activities of daily living, which can contribute to pain but are also affected by OA, Takahiro Sasahara, of the department of orthopedics at Juntendo University, Tokyo, and Koshigaya Municipal Hospital, Saitama, Japan, told attendees. The study also found that knee pain and mobility impairment were associated with sleep disturbances in older adults regardless of the severity of knee OA.

Luisa Cedin, a PhD student at Rush University, Chicago, who attended the presentation, noted the clinical implications of the interaction of daily activities with knee pain.

”I’m a physical therapist, and this could have a significant impact on the performance of the exercises that I’m requiring as a physical therapist,” Ms. Cedin said in an interview. “When you ask somebody who is not getting enough rest during the night – not only enough time but enough quality of rest – we know that we can expect a lower performance with any type of exercises, whether it’s less strength or force, less power, less agility, or less resistance or endurance, so this has a big impact on their quality of life.”

Mr. Sasahara cited research noting that acute pain occurs at the beginning of movement and during weight bearing and walking while chronic pain frequently occurs at night and in early morning awakenings. The prevalence of sleep disturbances in patients with chronic pain ranges from 50% to 80%, he said, and past evidence has shown the relationship between sleep and pain to be bidirectional.

For example, insomnia frequency and severity, sleep-onset problems, and sleep efficiency are all positively associated with pain sensitivity, and increasing severity of OA is linked to increasing prevalence of night knee pain and sleep problems, affecting quality of life, he said.

In this new study examining the relationship between sleep disturbance and knee pain and mobility, the researchers focused specifically on a population of older adults with knee OA. They analyzed data from the Bunkyo Health Study, which was conducted at Juntendo University’s Sportology Center to examine the association between metabolic, cardiovascular, cognitive dysfunction, and motor organ disorders in older adults from November 2015 to September 2018.

From the initial population of 1,630 adults, aged 65-84, who did not need medical treatment because of knee pain, the researchers analyzed data from 1,145 adults who the met this study’s criteria, which included MRI imaging of medial type knee OA. A little over half (55.7%) were women, with an average age of 73 and an average body mass index (BMI) of 22.8 kg/m².

In addition to blood and urine sampling, the researchers determined the severity of knee OA based on joint space width, femorotibial angle, and Kellgren and Lawrence (K/L) grade from x-rays in standing position. They also assessed the structure of knee OA using a whole-organ MRI score (WORMS), and pain and mobility with a visual analog scale, the Japan Knee Osteoarthritis Measure (JKOM), and the 25-question geriatric locomotive function scale.

The JKOM, based on the Western Ontario and McMaster Universities quality of life index for general knee OA, is adjusted to account for the Japanese lifestyle and covers four categories: knee pain and stiffness, a score for activities of daily living, a social activities score, and the patient’s health conditions.

Overall, 41.3% of the participants had sleep disturbances, based on a score of 6 or higher on the Pittsburgh Sleep Quality Index–Japanese. More women (55.7%) than men experienced sleep problems (P < .001), but there were no significant differences in the average age between those who did and those who did not have sleep issues. There were also no significance differences in BMI, joint space width, or femorotibial angle, which was an average 177.5 degrees in group with no sleep problems and 177.6 degrees in the group with sleep disturbances.

The proportion of participants experiencing sleep disturbances increased with increasing K/L grade of OA: 56.8% of those with K/L grade 4 had sleep problems, compared with 40.9% of those with K/L grade 3, 42.1% of those with K/L grade 2, and 33.7% of those with K/L grade 1, resulting in 30% greater odds of sleep disturbance with a higher K/L grade (odds ratio, 1.3; P = .011).

Knee pain at night was also significantly associated with severity of OA based on the K/L grade. While only 6.9% of participants reported pain at night overall, nearly 1 in 3 (29.5%) of those with K/L grade 4 reported pain at night, compared with 3.4% of those with K/L grade 1 (P < .001). (Night pain occurred in 5.4% of those with K/L grade 2 and 16.1% with K/L grade 3.)

However, after adjusting for age, gender, and BMI, the severity of knee OA was not significantly associated with sleep disturbance based on K/L grade, joint space width, femoro-tibial angle, and/or WORMS. But knee pain remained significantly associated with sleep disturbance after adjustment based on the visual analog scale and the JKOM (P < .001 for both).

Sleep problems were also significantly associated with each subcategory of the JKOM after adjustment (P < .001 for all but social activities, which was P = .014).

“Activities of daily living may affect the occurrence of knee pain at night,” Mr. Sasahara said, and “sleep disturbance may also disturb quality of life.” If sleep disturbances related to nighttime knee pain are linked to activities of daily living, then “not only knee pain but also activities of daily living need to be improved in order to improve sleep.”

He noted several of the study’s limitations, including the fact that lifestyle habits and work were not taken into account, nor did the researchers evaluate sleep disturbances potentially resulting from a medical illness. The researchers also only examined knee pain, not pain in other parts of the body.

The research was funded by Juntendo University; the Strategic Research Foundation at Private Universities; KAKENHI from the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Mizuno Sports Promotion Foundation; and the Mitsui Life Social Welfare Foundation. Mr. Sasahara and Ms. Cedin had no disclosures.

DENVER – The relationship between nighttime knee pain from osteoarthritis and sleep disturbances is more complex than a simple association, according to new research presented at the Osteoarthritis Research Society International 2023 World Congress.

The findings suggested that the association between knee OA pain and sleep problems was also linked to activities of daily living, which can contribute to pain but are also affected by OA, Takahiro Sasahara, of the department of orthopedics at Juntendo University, Tokyo, and Koshigaya Municipal Hospital, Saitama, Japan, told attendees. The study also found that knee pain and mobility impairment were associated with sleep disturbances in older adults regardless of the severity of knee OA.

Luisa Cedin, a PhD student at Rush University, Chicago, who attended the presentation, noted the clinical implications of the interaction of daily activities with knee pain.

”I’m a physical therapist, and this could have a significant impact on the performance of the exercises that I’m requiring as a physical therapist,” Ms. Cedin said in an interview. “When you ask somebody who is not getting enough rest during the night – not only enough time but enough quality of rest – we know that we can expect a lower performance with any type of exercises, whether it’s less strength or force, less power, less agility, or less resistance or endurance, so this has a big impact on their quality of life.”

Mr. Sasahara cited research noting that acute pain occurs at the beginning of movement and during weight bearing and walking while chronic pain frequently occurs at night and in early morning awakenings. The prevalence of sleep disturbances in patients with chronic pain ranges from 50% to 80%, he said, and past evidence has shown the relationship between sleep and pain to be bidirectional.

For example, insomnia frequency and severity, sleep-onset problems, and sleep efficiency are all positively associated with pain sensitivity, and increasing severity of OA is linked to increasing prevalence of night knee pain and sleep problems, affecting quality of life, he said.

In this new study examining the relationship between sleep disturbance and knee pain and mobility, the researchers focused specifically on a population of older adults with knee OA. They analyzed data from the Bunkyo Health Study, which was conducted at Juntendo University’s Sportology Center to examine the association between metabolic, cardiovascular, cognitive dysfunction, and motor organ disorders in older adults from November 2015 to September 2018.

From the initial population of 1,630 adults, aged 65-84, who did not need medical treatment because of knee pain, the researchers analyzed data from 1,145 adults who the met this study’s criteria, which included MRI imaging of medial type knee OA. A little over half (55.7%) were women, with an average age of 73 and an average body mass index (BMI) of 22.8 kg/m².

In addition to blood and urine sampling, the researchers determined the severity of knee OA based on joint space width, femorotibial angle, and Kellgren and Lawrence (K/L) grade from x-rays in standing position. They also assessed the structure of knee OA using a whole-organ MRI score (WORMS), and pain and mobility with a visual analog scale, the Japan Knee Osteoarthritis Measure (JKOM), and the 25-question geriatric locomotive function scale.

The JKOM, based on the Western Ontario and McMaster Universities quality of life index for general knee OA, is adjusted to account for the Japanese lifestyle and covers four categories: knee pain and stiffness, a score for activities of daily living, a social activities score, and the patient’s health conditions.

Overall, 41.3% of the participants had sleep disturbances, based on a score of 6 or higher on the Pittsburgh Sleep Quality Index–Japanese. More women (55.7%) than men experienced sleep problems (P < .001), but there were no significant differences in the average age between those who did and those who did not have sleep issues. There were also no significance differences in BMI, joint space width, or femorotibial angle, which was an average 177.5 degrees in group with no sleep problems and 177.6 degrees in the group with sleep disturbances.

The proportion of participants experiencing sleep disturbances increased with increasing K/L grade of OA: 56.8% of those with K/L grade 4 had sleep problems, compared with 40.9% of those with K/L grade 3, 42.1% of those with K/L grade 2, and 33.7% of those with K/L grade 1, resulting in 30% greater odds of sleep disturbance with a higher K/L grade (odds ratio, 1.3; P = .011).

Knee pain at night was also significantly associated with severity of OA based on the K/L grade. While only 6.9% of participants reported pain at night overall, nearly 1 in 3 (29.5%) of those with K/L grade 4 reported pain at night, compared with 3.4% of those with K/L grade 1 (P < .001). (Night pain occurred in 5.4% of those with K/L grade 2 and 16.1% with K/L grade 3.)

However, after adjusting for age, gender, and BMI, the severity of knee OA was not significantly associated with sleep disturbance based on K/L grade, joint space width, femoro-tibial angle, and/or WORMS. But knee pain remained significantly associated with sleep disturbance after adjustment based on the visual analog scale and the JKOM (P < .001 for both).

Sleep problems were also significantly associated with each subcategory of the JKOM after adjustment (P < .001 for all but social activities, which was P = .014).

“Activities of daily living may affect the occurrence of knee pain at night,” Mr. Sasahara said, and “sleep disturbance may also disturb quality of life.” If sleep disturbances related to nighttime knee pain are linked to activities of daily living, then “not only knee pain but also activities of daily living need to be improved in order to improve sleep.”

He noted several of the study’s limitations, including the fact that lifestyle habits and work were not taken into account, nor did the researchers evaluate sleep disturbances potentially resulting from a medical illness. The researchers also only examined knee pain, not pain in other parts of the body.

The research was funded by Juntendo University; the Strategic Research Foundation at Private Universities; KAKENHI from the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Mizuno Sports Promotion Foundation; and the Mitsui Life Social Welfare Foundation. Mr. Sasahara and Ms. Cedin had no disclosures.

DENVER – The relationship between nighttime knee pain from osteoarthritis and sleep disturbances is more complex than a simple association, according to new research presented at the Osteoarthritis Research Society International 2023 World Congress.

The findings suggested that the association between knee OA pain and sleep problems was also linked to activities of daily living, which can contribute to pain but are also affected by OA, Takahiro Sasahara, of the department of orthopedics at Juntendo University, Tokyo, and Koshigaya Municipal Hospital, Saitama, Japan, told attendees. The study also found that knee pain and mobility impairment were associated with sleep disturbances in older adults regardless of the severity of knee OA.

Luisa Cedin, a PhD student at Rush University, Chicago, who attended the presentation, noted the clinical implications of the interaction of daily activities with knee pain.

”I’m a physical therapist, and this could have a significant impact on the performance of the exercises that I’m requiring as a physical therapist,” Ms. Cedin said in an interview. “When you ask somebody who is not getting enough rest during the night – not only enough time but enough quality of rest – we know that we can expect a lower performance with any type of exercises, whether it’s less strength or force, less power, less agility, or less resistance or endurance, so this has a big impact on their quality of life.”

Mr. Sasahara cited research noting that acute pain occurs at the beginning of movement and during weight bearing and walking while chronic pain frequently occurs at night and in early morning awakenings. The prevalence of sleep disturbances in patients with chronic pain ranges from 50% to 80%, he said, and past evidence has shown the relationship between sleep and pain to be bidirectional.

For example, insomnia frequency and severity, sleep-onset problems, and sleep efficiency are all positively associated with pain sensitivity, and increasing severity of OA is linked to increasing prevalence of night knee pain and sleep problems, affecting quality of life, he said.

In this new study examining the relationship between sleep disturbance and knee pain and mobility, the researchers focused specifically on a population of older adults with knee OA. They analyzed data from the Bunkyo Health Study, which was conducted at Juntendo University’s Sportology Center to examine the association between metabolic, cardiovascular, cognitive dysfunction, and motor organ disorders in older adults from November 2015 to September 2018.

From the initial population of 1,630 adults, aged 65-84, who did not need medical treatment because of knee pain, the researchers analyzed data from 1,145 adults who the met this study’s criteria, which included MRI imaging of medial type knee OA. A little over half (55.7%) were women, with an average age of 73 and an average body mass index (BMI) of 22.8 kg/m².

In addition to blood and urine sampling, the researchers determined the severity of knee OA based on joint space width, femorotibial angle, and Kellgren and Lawrence (K/L) grade from x-rays in standing position. They also assessed the structure of knee OA using a whole-organ MRI score (WORMS), and pain and mobility with a visual analog scale, the Japan Knee Osteoarthritis Measure (JKOM), and the 25-question geriatric locomotive function scale.

The JKOM, based on the Western Ontario and McMaster Universities quality of life index for general knee OA, is adjusted to account for the Japanese lifestyle and covers four categories: knee pain and stiffness, a score for activities of daily living, a social activities score, and the patient’s health conditions.

Overall, 41.3% of the participants had sleep disturbances, based on a score of 6 or higher on the Pittsburgh Sleep Quality Index–Japanese. More women (55.7%) than men experienced sleep problems (P < .001), but there were no significant differences in the average age between those who did and those who did not have sleep issues. There were also no significance differences in BMI, joint space width, or femorotibial angle, which was an average 177.5 degrees in group with no sleep problems and 177.6 degrees in the group with sleep disturbances.

The proportion of participants experiencing sleep disturbances increased with increasing K/L grade of OA: 56.8% of those with K/L grade 4 had sleep problems, compared with 40.9% of those with K/L grade 3, 42.1% of those with K/L grade 2, and 33.7% of those with K/L grade 1, resulting in 30% greater odds of sleep disturbance with a higher K/L grade (odds ratio, 1.3; P = .011).

Knee pain at night was also significantly associated with severity of OA based on the K/L grade. While only 6.9% of participants reported pain at night overall, nearly 1 in 3 (29.5%) of those with K/L grade 4 reported pain at night, compared with 3.4% of those with K/L grade 1 (P < .001). (Night pain occurred in 5.4% of those with K/L grade 2 and 16.1% with K/L grade 3.)

However, after adjusting for age, gender, and BMI, the severity of knee OA was not significantly associated with sleep disturbance based on K/L grade, joint space width, femoro-tibial angle, and/or WORMS. But knee pain remained significantly associated with sleep disturbance after adjustment based on the visual analog scale and the JKOM (P < .001 for both).

Sleep problems were also significantly associated with each subcategory of the JKOM after adjustment (P < .001 for all but social activities, which was P = .014).

“Activities of daily living may affect the occurrence of knee pain at night,” Mr. Sasahara said, and “sleep disturbance may also disturb quality of life.” If sleep disturbances related to nighttime knee pain are linked to activities of daily living, then “not only knee pain but also activities of daily living need to be improved in order to improve sleep.”

He noted several of the study’s limitations, including the fact that lifestyle habits and work were not taken into account, nor did the researchers evaluate sleep disturbances potentially resulting from a medical illness. The researchers also only examined knee pain, not pain in other parts of the body.

The research was funded by Juntendo University; the Strategic Research Foundation at Private Universities; KAKENHI from the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Mizuno Sports Promotion Foundation; and the Mitsui Life Social Welfare Foundation. Mr. Sasahara and Ms. Cedin had no disclosures.

Into thin, but healthy, air

Human civilization has essentially been built on proximity to water. Ancient civilizations in Mesopotamia, Egypt, Greece, China, and India were all intimately connected to either rivers or the ocean. Even today, with all our technology, about a third of Earth’s 8 billion people live within 100 vertical meters of sea level, and the median person lives at an elevation of just 200 meters.

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All things considered, one might imagine life is pretty tough for the 2 million people living at an elevation of 4,500 meters (nearly 15,000 feet). Not too many Wal-Marts or McDonalds up there. Oh, and not much air either. And for most of us not named Spongebob, air is good.

Or is it? That’s the question posed by a new study. After all, the researchers said, people living at high altitudes, where the air has only 11% effective oxygen instead of the 21% we have at low altitude, have significantly lower rates of metabolic disorders such as diabetes and heart diseases. Maybe breathing isn’t all it’s cracked up to be.

To find out, the researchers placed a group of mice in environments with either 11% oxygen or 8% oxygen. This netted them a bunch of very tired mice. Hey, sudden altitude gain doesn’t go too well for us either, but after 3 weeks, all the mice in the hypoxic environments had regained their normal movement and were behaving as any mouse would.

While the critters seemed normal on the outside, a closer examination found the truth. Their metabolism had been permanently altered, and their blood sugar and weight went down and never bounced back up. Further examination through PET scans showed that the hypoxic mice’s organs showed an increase in glucose metabolism and that brown fat and skeletal muscles reduced the amount of sugar they used.

This goes against the prevailing assumption about hypoxic conditions, the researchers said, since it was previously theorized that the body simply burned more glucose in response to having less oxygen. And while that’s true, our organs also conspicuously use less glucose. Currently, many athletes use hypoxic environments to train, but these new data suggest that people with metabolic disorders also would see benefits from living in low-oxygen environments.

Do you know what this means? All we have to do to stop diabetes is take civilization and push it somewhere else. This can’t possibly end badly.
 

Sleep survey: The restless majority

Newsflash! This just in: Nobody is sleeping well.

When we go to bed, our goal is to get rest, right? Sorry America, but you’re falling short. In a recent survey conducted by OnePoll for Purple Mattress, almost two-thirds of the 2,011 participants considered themselves restless sleepers.

klebercordeiro/Getty Images

Not surprised. So what’s keeping us up?

Snoring partners (20%) and anxiety (26%) made the list, but the award for top complaint goes to body pain. Back pain was most prevalent, reported by 36% of respondents, followed by neck pain (33%) and shoulder pain (24%). No wonder, then, that only 10% of the group reported feeling well rested when they woke up.

Do you ever blame your tiredness on sleeping funny? Well, we all kind of sleep funny, and yet we’re still not sleeping well.

The largest proportion of people like to sleep on their side (48%), compared with 18% on their back and 17% on their stomach. The main reasons to choose certain positions were to ease soreness or sleep better, both at 28%. The largest share of participants (47%) reported sleeping in a “yearner” position, while 40% lay on their stomachs in the “free faller” position, and 39% reported using the “soldier” position.

Regardless of the method people use to get to sleep or the position they’re in, the goal is always the same. We’re all just trying to figure out what’s the right one for us.
 

Seen a UFO recently? Don’t blame COVID

First of all, because we know you’re going to be thinking it in a minute, no, we did not make this up. With COVID-19 still hanging around, there’s no need for fabrication on our part.

Jat AM/Pixabay

The pandemic, clearly, has caused humans to do some strange things over the last 3 years, but what about some of the more, shall we say … eccentric behavior that people were already exhibiting before COVID found its way into our lives?

If, like R. Chase Cockrell, PhD, of the University of Vermont and associates at the Center for UFO Studies, you were wondering if the pandemic affected UFO reporting, then wonder no more. After all, with all that extra time being spent outdoors back in 2020 and all the additional anxiety, surely somebody must have seen something.

The investigators started with the basics by analyzing data from the National UFO Reporting Center and the Mutual UFO Network. Sightings did increase by about 600 in each database during 2020, compared with 2018 and 2019, but not because of the pandemic.

That’s right, we can’t pin this one on our good friend SARS-CoV-2. Further analysis showed that the launches of SpaceX Starlink satellites – sometimes as many as 60 at a time – probably caused the increase in UFO sightings, which means that our favorite billionaire, Elon Musk, is to blame. Yup, the genial Mr. Muskellunge did something that even a global pandemic couldn’t, and yet we vaccinate for COVID.

Next week on tenuous connections: A new study links the 2020 presidential election to increased emergency department visits for external hemorrhoids.

See? That’s fabrication. We made that up.

This article was updated 5/15/23.

Into thin, but healthy, air

Human civilization has essentially been built on proximity to water. Ancient civilizations in Mesopotamia, Egypt, Greece, China, and India were all intimately connected to either rivers or the ocean. Even today, with all our technology, about a third of Earth’s 8 billion people live within 100 vertical meters of sea level, and the median person lives at an elevation of just 200 meters.

pxfuel

All things considered, one might imagine life is pretty tough for the 2 million people living at an elevation of 4,500 meters (nearly 15,000 feet). Not too many Wal-Marts or McDonalds up there. Oh, and not much air either. And for most of us not named Spongebob, air is good.

Or is it? That’s the question posed by a new study. After all, the researchers said, people living at high altitudes, where the air has only 11% effective oxygen instead of the 21% we have at low altitude, have significantly lower rates of metabolic disorders such as diabetes and heart diseases. Maybe breathing isn’t all it’s cracked up to be.

To find out, the researchers placed a group of mice in environments with either 11% oxygen or 8% oxygen. This netted them a bunch of very tired mice. Hey, sudden altitude gain doesn’t go too well for us either, but after 3 weeks, all the mice in the hypoxic environments had regained their normal movement and were behaving as any mouse would.

While the critters seemed normal on the outside, a closer examination found the truth. Their metabolism had been permanently altered, and their blood sugar and weight went down and never bounced back up. Further examination through PET scans showed that the hypoxic mice’s organs showed an increase in glucose metabolism and that brown fat and skeletal muscles reduced the amount of sugar they used.

This goes against the prevailing assumption about hypoxic conditions, the researchers said, since it was previously theorized that the body simply burned more glucose in response to having less oxygen. And while that’s true, our organs also conspicuously use less glucose. Currently, many athletes use hypoxic environments to train, but these new data suggest that people with metabolic disorders also would see benefits from living in low-oxygen environments.

Do you know what this means? All we have to do to stop diabetes is take civilization and push it somewhere else. This can’t possibly end badly.
 

Sleep survey: The restless majority

Newsflash! This just in: Nobody is sleeping well.

When we go to bed, our goal is to get rest, right? Sorry America, but you’re falling short. In a recent survey conducted by OnePoll for Purple Mattress, almost two-thirds of the 2,011 participants considered themselves restless sleepers.

klebercordeiro/Getty Images

Not surprised. So what’s keeping us up?

Snoring partners (20%) and anxiety (26%) made the list, but the award for top complaint goes to body pain. Back pain was most prevalent, reported by 36% of respondents, followed by neck pain (33%) and shoulder pain (24%). No wonder, then, that only 10% of the group reported feeling well rested when they woke up.

Do you ever blame your tiredness on sleeping funny? Well, we all kind of sleep funny, and yet we’re still not sleeping well.

The largest proportion of people like to sleep on their side (48%), compared with 18% on their back and 17% on their stomach. The main reasons to choose certain positions were to ease soreness or sleep better, both at 28%. The largest share of participants (47%) reported sleeping in a “yearner” position, while 40% lay on their stomachs in the “free faller” position, and 39% reported using the “soldier” position.

Regardless of the method people use to get to sleep or the position they’re in, the goal is always the same. We’re all just trying to figure out what’s the right one for us.
 

Seen a UFO recently? Don’t blame COVID

First of all, because we know you’re going to be thinking it in a minute, no, we did not make this up. With COVID-19 still hanging around, there’s no need for fabrication on our part.

Jat AM/Pixabay

The pandemic, clearly, has caused humans to do some strange things over the last 3 years, but what about some of the more, shall we say … eccentric behavior that people were already exhibiting before COVID found its way into our lives?

If, like R. Chase Cockrell, PhD, of the University of Vermont and associates at the Center for UFO Studies, you were wondering if the pandemic affected UFO reporting, then wonder no more. After all, with all that extra time being spent outdoors back in 2020 and all the additional anxiety, surely somebody must have seen something.

The investigators started with the basics by analyzing data from the National UFO Reporting Center and the Mutual UFO Network. Sightings did increase by about 600 in each database during 2020, compared with 2018 and 2019, but not because of the pandemic.

That’s right, we can’t pin this one on our good friend SARS-CoV-2. Further analysis showed that the launches of SpaceX Starlink satellites – sometimes as many as 60 at a time – probably caused the increase in UFO sightings, which means that our favorite billionaire, Elon Musk, is to blame. Yup, the genial Mr. Muskellunge did something that even a global pandemic couldn’t, and yet we vaccinate for COVID.

Next week on tenuous connections: A new study links the 2020 presidential election to increased emergency department visits for external hemorrhoids.

See? That’s fabrication. We made that up.

This article was updated 5/15/23.

Into thin, but healthy, air

Human civilization has essentially been built on proximity to water. Ancient civilizations in Mesopotamia, Egypt, Greece, China, and India were all intimately connected to either rivers or the ocean. Even today, with all our technology, about a third of Earth’s 8 billion people live within 100 vertical meters of sea level, and the median person lives at an elevation of just 200 meters.

pxfuel

All things considered, one might imagine life is pretty tough for the 2 million people living at an elevation of 4,500 meters (nearly 15,000 feet). Not too many Wal-Marts or McDonalds up there. Oh, and not much air either. And for most of us not named Spongebob, air is good.

Or is it? That’s the question posed by a new study. After all, the researchers said, people living at high altitudes, where the air has only 11% effective oxygen instead of the 21% we have at low altitude, have significantly lower rates of metabolic disorders such as diabetes and heart diseases. Maybe breathing isn’t all it’s cracked up to be.

To find out, the researchers placed a group of mice in environments with either 11% oxygen or 8% oxygen. This netted them a bunch of very tired mice. Hey, sudden altitude gain doesn’t go too well for us either, but after 3 weeks, all the mice in the hypoxic environments had regained their normal movement and were behaving as any mouse would.

While the critters seemed normal on the outside, a closer examination found the truth. Their metabolism had been permanently altered, and their blood sugar and weight went down and never bounced back up. Further examination through PET scans showed that the hypoxic mice’s organs showed an increase in glucose metabolism and that brown fat and skeletal muscles reduced the amount of sugar they used.

This goes against the prevailing assumption about hypoxic conditions, the researchers said, since it was previously theorized that the body simply burned more glucose in response to having less oxygen. And while that’s true, our organs also conspicuously use less glucose. Currently, many athletes use hypoxic environments to train, but these new data suggest that people with metabolic disorders also would see benefits from living in low-oxygen environments.

Do you know what this means? All we have to do to stop diabetes is take civilization and push it somewhere else. This can’t possibly end badly.
 

Sleep survey: The restless majority

Newsflash! This just in: Nobody is sleeping well.

When we go to bed, our goal is to get rest, right? Sorry America, but you’re falling short. In a recent survey conducted by OnePoll for Purple Mattress, almost two-thirds of the 2,011 participants considered themselves restless sleepers.

klebercordeiro/Getty Images

Not surprised. So what’s keeping us up?

Snoring partners (20%) and anxiety (26%) made the list, but the award for top complaint goes to body pain. Back pain was most prevalent, reported by 36% of respondents, followed by neck pain (33%) and shoulder pain (24%). No wonder, then, that only 10% of the group reported feeling well rested when they woke up.

Do you ever blame your tiredness on sleeping funny? Well, we all kind of sleep funny, and yet we’re still not sleeping well.

The largest proportion of people like to sleep on their side (48%), compared with 18% on their back and 17% on their stomach. The main reasons to choose certain positions were to ease soreness or sleep better, both at 28%. The largest share of participants (47%) reported sleeping in a “yearner” position, while 40% lay on their stomachs in the “free faller” position, and 39% reported using the “soldier” position.

Regardless of the method people use to get to sleep or the position they’re in, the goal is always the same. We’re all just trying to figure out what’s the right one for us.
 

Seen a UFO recently? Don’t blame COVID

First of all, because we know you’re going to be thinking it in a minute, no, we did not make this up. With COVID-19 still hanging around, there’s no need for fabrication on our part.

Jat AM/Pixabay

The pandemic, clearly, has caused humans to do some strange things over the last 3 years, but what about some of the more, shall we say … eccentric behavior that people were already exhibiting before COVID found its way into our lives?

If, like R. Chase Cockrell, PhD, of the University of Vermont and associates at the Center for UFO Studies, you were wondering if the pandemic affected UFO reporting, then wonder no more. After all, with all that extra time being spent outdoors back in 2020 and all the additional anxiety, surely somebody must have seen something.

The investigators started with the basics by analyzing data from the National UFO Reporting Center and the Mutual UFO Network. Sightings did increase by about 600 in each database during 2020, compared with 2018 and 2019, but not because of the pandemic.

That’s right, we can’t pin this one on our good friend SARS-CoV-2. Further analysis showed that the launches of SpaceX Starlink satellites – sometimes as many as 60 at a time – probably caused the increase in UFO sightings, which means that our favorite billionaire, Elon Musk, is to blame. Yup, the genial Mr. Muskellunge did something that even a global pandemic couldn’t, and yet we vaccinate for COVID.

Next week on tenuous connections: A new study links the 2020 presidential election to increased emergency department visits for external hemorrhoids.

See? That’s fabrication. We made that up.

This article was updated 5/15/23.

Restless legs syndrome (RLS) is associated with an elevated risk of dementia among older adults, suggesting the disorder may be a risk factor for dementia or a very early noncognitive sign of dementia, researchers say.

In a large population-based cohort study, adults with RLS were significantly more likely to develop dementia over more than a decade than were their peers without RLS.

If confirmed in future studies, “regular check-ups for cognitive decline in older patients with RLS may facilitate earlier detection and intervention for those with dementia risk,” wrote investigators led by Eosu Kim, MD, PhD, with Yonsei University, Seoul, Republic of Korea.

The study was published online in Alzheimer’s Research and Therapy.
 

Sleep disorders and dementia

RLS is associated with poor sleep, depression/anxiety, poor diet, microvasculopathy, and hypoxia – all of which are known risk factors for dementia. However, the relationship between RLS and incident dementia has been unclear.

The researchers compared risk for all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) among 2,501 adults with newly diagnosed RLS and 9,977 matched control persons participating in the Korean National Health Insurance Service–Elderly Cohort, a nationwide population-based cohort of adults aged 60 and older.

The mean age of the cohort was 73 years; most of the participants were women (65%). Among all 12,478 participants, 874 (7%) developed all-cause dementia during follow-up – 475 (54%) developed AD, and 194 (22%) developed VaD.

The incidence of all-cause dementia was significantly higher among the RLS group than among the control group (10.4% vs. 6.2%). Incidence rates of AD and VaD (5.6% and 2.6%, respectively) were also higher in the RLS group than in the control group (3.4% and 1.3%, respectively).

In Cox regression analysis, RLS was significantly associated with an increased risk of all-cause dementia (adjusted hazard ratio [aHR], 1.46; 95% confidence interval [CI], 1.24-1.72), AD (aHR 1.38; 95% CI, 1.11-1.72) and VaD (aHR, 1.81; 95% CI, 1.30-2.53).

The researchers noted that RLS may precede deterioration of cognitive function, leading to dementia, and they suggest that RLS could be regarded as a “newly identified” risk factor or prodromal sign of dementia.
 

Modifiable risk factor

Reached for comment, Thanh Dang-Vu, MD, PhD, professor and research chair in sleep, neuroimaging, and cognitive health at Concordia University in Montreal, said there is now “increasing literature that shows sleep as a modifiable risk factor for cognitive decline.

“Previous evidence indicates that both sleep apnea and insomnia disorder increase the risk for cognitive decline and possibly dementia. Here the study adds to this body of evidence linking sleep disorders to dementia, suggesting that RLS should also be considered as a sleep-related risk factor,” Dr. Dang-Vu told this news organization.

“More evidence is needed, though, as here, all diagnoses were based on national health insurance diagnostic codes, and it is likely there were missed diagnoses for RLS but also for other sleep disorders, as there was no systematic screening for them,” Dr. Dang-Vu cautioned.

Support for the study was provided by the Ministry of Health and Welfare, the Korean government, and Yonsei University. Dr. Kim and Dr. Dang-Vu reported no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.

Restless legs syndrome (RLS) is associated with an elevated risk of dementia among older adults, suggesting the disorder may be a risk factor for dementia or a very early noncognitive sign of dementia, researchers say.

In a large population-based cohort study, adults with RLS were significantly more likely to develop dementia over more than a decade than were their peers without RLS.

If confirmed in future studies, “regular check-ups for cognitive decline in older patients with RLS may facilitate earlier detection and intervention for those with dementia risk,” wrote investigators led by Eosu Kim, MD, PhD, with Yonsei University, Seoul, Republic of Korea.

The study was published online in Alzheimer’s Research and Therapy.
 

Sleep disorders and dementia

RLS is associated with poor sleep, depression/anxiety, poor diet, microvasculopathy, and hypoxia – all of which are known risk factors for dementia. However, the relationship between RLS and incident dementia has been unclear.

The researchers compared risk for all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) among 2,501 adults with newly diagnosed RLS and 9,977 matched control persons participating in the Korean National Health Insurance Service–Elderly Cohort, a nationwide population-based cohort of adults aged 60 and older.

The mean age of the cohort was 73 years; most of the participants were women (65%). Among all 12,478 participants, 874 (7%) developed all-cause dementia during follow-up – 475 (54%) developed AD, and 194 (22%) developed VaD.

The incidence of all-cause dementia was significantly higher among the RLS group than among the control group (10.4% vs. 6.2%). Incidence rates of AD and VaD (5.6% and 2.6%, respectively) were also higher in the RLS group than in the control group (3.4% and 1.3%, respectively).

In Cox regression analysis, RLS was significantly associated with an increased risk of all-cause dementia (adjusted hazard ratio [aHR], 1.46; 95% confidence interval [CI], 1.24-1.72), AD (aHR 1.38; 95% CI, 1.11-1.72) and VaD (aHR, 1.81; 95% CI, 1.30-2.53).

The researchers noted that RLS may precede deterioration of cognitive function, leading to dementia, and they suggest that RLS could be regarded as a “newly identified” risk factor or prodromal sign of dementia.
 

Modifiable risk factor

Reached for comment, Thanh Dang-Vu, MD, PhD, professor and research chair in sleep, neuroimaging, and cognitive health at Concordia University in Montreal, said there is now “increasing literature that shows sleep as a modifiable risk factor for cognitive decline.

“Previous evidence indicates that both sleep apnea and insomnia disorder increase the risk for cognitive decline and possibly dementia. Here the study adds to this body of evidence linking sleep disorders to dementia, suggesting that RLS should also be considered as a sleep-related risk factor,” Dr. Dang-Vu told this news organization.

“More evidence is needed, though, as here, all diagnoses were based on national health insurance diagnostic codes, and it is likely there were missed diagnoses for RLS but also for other sleep disorders, as there was no systematic screening for them,” Dr. Dang-Vu cautioned.

Support for the study was provided by the Ministry of Health and Welfare, the Korean government, and Yonsei University. Dr. Kim and Dr. Dang-Vu reported no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.

Restless legs syndrome (RLS) is associated with an elevated risk of dementia among older adults, suggesting the disorder may be a risk factor for dementia or a very early noncognitive sign of dementia, researchers say.

In a large population-based cohort study, adults with RLS were significantly more likely to develop dementia over more than a decade than were their peers without RLS.

If confirmed in future studies, “regular check-ups for cognitive decline in older patients with RLS may facilitate earlier detection and intervention for those with dementia risk,” wrote investigators led by Eosu Kim, MD, PhD, with Yonsei University, Seoul, Republic of Korea.

The study was published online in Alzheimer’s Research and Therapy.
 

Sleep disorders and dementia

RLS is associated with poor sleep, depression/anxiety, poor diet, microvasculopathy, and hypoxia – all of which are known risk factors for dementia. However, the relationship between RLS and incident dementia has been unclear.

The researchers compared risk for all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) among 2,501 adults with newly diagnosed RLS and 9,977 matched control persons participating in the Korean National Health Insurance Service–Elderly Cohort, a nationwide population-based cohort of adults aged 60 and older.

The mean age of the cohort was 73 years; most of the participants were women (65%). Among all 12,478 participants, 874 (7%) developed all-cause dementia during follow-up – 475 (54%) developed AD, and 194 (22%) developed VaD.

The incidence of all-cause dementia was significantly higher among the RLS group than among the control group (10.4% vs. 6.2%). Incidence rates of AD and VaD (5.6% and 2.6%, respectively) were also higher in the RLS group than in the control group (3.4% and 1.3%, respectively).

In Cox regression analysis, RLS was significantly associated with an increased risk of all-cause dementia (adjusted hazard ratio [aHR], 1.46; 95% confidence interval [CI], 1.24-1.72), AD (aHR 1.38; 95% CI, 1.11-1.72) and VaD (aHR, 1.81; 95% CI, 1.30-2.53).

The researchers noted that RLS may precede deterioration of cognitive function, leading to dementia, and they suggest that RLS could be regarded as a “newly identified” risk factor or prodromal sign of dementia.
 

Modifiable risk factor

Reached for comment, Thanh Dang-Vu, MD, PhD, professor and research chair in sleep, neuroimaging, and cognitive health at Concordia University in Montreal, said there is now “increasing literature that shows sleep as a modifiable risk factor for cognitive decline.

“Previous evidence indicates that both sleep apnea and insomnia disorder increase the risk for cognitive decline and possibly dementia. Here the study adds to this body of evidence linking sleep disorders to dementia, suggesting that RLS should also be considered as a sleep-related risk factor,” Dr. Dang-Vu told this news organization.

“More evidence is needed, though, as here, all diagnoses were based on national health insurance diagnostic codes, and it is likely there were missed diagnoses for RLS but also for other sleep disorders, as there was no systematic screening for them,” Dr. Dang-Vu cautioned.

Support for the study was provided by the Ministry of Health and Welfare, the Korean government, and Yonsei University. Dr. Kim and Dr. Dang-Vu reported no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.

NEW ORLEANS – Cognitive behavioral therapy (CBT) should be the first-line therapy for insomnia in seniors, but many clinicians are unaware of its benefits, experts say.

Rajesh R. Tampi

“The lack of awareness among clinicians who take care of older adults that CBT for insomnia (CBT-I) is an effective treatment for insomnia is an issue,” Rajesh R. Tampi, MD, professor and chairman of the department of psychiatry, Creighton University, Omaha, Neb., told this news organization.

Dr. Tampi was among the speakers during a session as part of the American Association for Geriatric Psychiatry annual meeting addressing the complex challenges of treating insomnia in older patients, who tend to have higher rates of insomnia than their younger counterparts.

The prevalence of insomnia in older adults is estimated to be 20%-40%, and medication is frequently the first treatment choice, a less than ideal approach, said Dr. Tampi.

“Prescribing sedatives and hypnotics, which can cause severe adverse effects, without a thorough assessment that includes comorbidities that may be causing the insomnia” is among the biggest mistakes clinicians make in the treatment of insomnia in older patients, Dr. Tampi said in an interview.

“It’s our duty as providers to first take a good assessment, talk about polymorbidity, and try to address those conditions, and judiciously use medications in conjunction with at least components of CBT-I,” he said.
 

Long-term safety, efficacy unclear

About one-third of older adults take at least one form of pharmacological treatment for insomnia symptoms, said Ebony Dix, MD, assistant professor of psychiatry at Yale University, New Haven, Conn., in a separate talk during the session. This, despite the low-risk profile of CBT and recommendations from various medical societies that CBT should be tried first.

Dr. Dix noted that medications approved for insomnia by the U.S. Food and Drug Administration, including melatonin receptor agonists, heterocyclics, and dual orexin receptor antagonists (DORAs), can play an important role in the short-term management of insomnia, but their long-term effects are unknown.

“Pharmacotherapeutic agents may be effective in the short term, but there is a lack of sufficient, statistically significant data to support the long-term safety and efficacy of any [sleep] medication, especially in aging adults, due to the impact of hypnotic drugs on sleep architecture, the impact of aging on pharmacokinetics, as well as polypharmacy and drug-to-drug interactions,” Dr. Dix said. She noted that clinical trials of insomnia drugs rarely include geriatric patients.

University of South Carolina

The American Academy of Sleep Medicine recommends CBT-I as first-line treatment for insomnia, with the key benefit being its exemplary safety profile, said Shilpa Srinivasan, MD, a professor of clinical psychiatry at the University of South Carolina, Columbia, who also presented during the session.

“The biggest [attribute] of CBT-I management strategies is the low risk of side effects,” she said. “How many medications can we say that about?”

The CBT-I intervention includes a focus on key components of lifestyle and mental health issues to improve sleep. These include the following:

• Strictly restricting sleep hours for bedtime and arising (with napping discouraged).
• Control of stimulus to disrupt falling asleep.
• Cognitive therapy to identify and replace maladaptive beliefs.
• Control of sleep hygiene for optimal sleep.
• Relaxation training.

Keys to success

Dr. Srinivasan noted one recent study of CBT-I among patients aged 60 and older with insomnia and depression. The 156 participants randomized to receive weekly 120-minute CBT-I sessions over 2 months were significantly less likely to develop new or recurrent major depression versus their counterparts randomized to receive sleep education (hazard ratio, 0.51; P = .02).

However, CBT-I is more labor intensive than medication and requires provider training and motivation, and commitment on the part of the patient, to be successful.

“We really need to ensure that even when patients are receiving pharmacologic interventions for insomnia that we provide psychoeducation. At the end of the day, some of these nonpharmacologic components can make or break the success of pharmacotherapy,” said Dr. Srinivasan.

Whether using CBT-I alone or in combination with pharmacotherapy, the intervention does not necessarily have to include all components to be beneficial, she said.

“I think one of the challenges in incorporating CBT-I is the misconception that it is an all-or-nothing approach wherein every modality must be utilized,” she said. “While multicomponent CBT-I has been shown to be effective, the individual components can be incorporated into patient encounters in a stepped approach.”

Informing patients that they have options other than medications and involving them in decision-making is key, she added.

“In the case of insomnia, this is particularly relevant because of the physical and emotional distress that it causes,” Dr. Srinivasan said. “Patients often seek over-the-counter medications or other nonprescribed agents to try to obtain relief even before seeking treatment in a health care setting. There is less awareness about evidence-based and effective nonpharmacologic treatments such as CBT-I.”

Dr. Tampi, Dr. Dix, and Dr. Srinivasan have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

NEW ORLEANS – Cognitive behavioral therapy (CBT) should be the first-line therapy for insomnia in seniors, but many clinicians are unaware of its benefits, experts say.

Rajesh R. Tampi

“The lack of awareness among clinicians who take care of older adults that CBT for insomnia (CBT-I) is an effective treatment for insomnia is an issue,” Rajesh R. Tampi, MD, professor and chairman of the department of psychiatry, Creighton University, Omaha, Neb., told this news organization.

Dr. Tampi was among the speakers during a session as part of the American Association for Geriatric Psychiatry annual meeting addressing the complex challenges of treating insomnia in older patients, who tend to have higher rates of insomnia than their younger counterparts.

The prevalence of insomnia in older adults is estimated to be 20%-40%, and medication is frequently the first treatment choice, a less than ideal approach, said Dr. Tampi.

“Prescribing sedatives and hypnotics, which can cause severe adverse effects, without a thorough assessment that includes comorbidities that may be causing the insomnia” is among the biggest mistakes clinicians make in the treatment of insomnia in older patients, Dr. Tampi said in an interview.

“It’s our duty as providers to first take a good assessment, talk about polymorbidity, and try to address those conditions, and judiciously use medications in conjunction with at least components of CBT-I,” he said.
 

Long-term safety, efficacy unclear

About one-third of older adults take at least one form of pharmacological treatment for insomnia symptoms, said Ebony Dix, MD, assistant professor of psychiatry at Yale University, New Haven, Conn., in a separate talk during the session. This, despite the low-risk profile of CBT and recommendations from various medical societies that CBT should be tried first.

Dr. Dix noted that medications approved for insomnia by the U.S. Food and Drug Administration, including melatonin receptor agonists, heterocyclics, and dual orexin receptor antagonists (DORAs), can play an important role in the short-term management of insomnia, but their long-term effects are unknown.

“Pharmacotherapeutic agents may be effective in the short term, but there is a lack of sufficient, statistically significant data to support the long-term safety and efficacy of any [sleep] medication, especially in aging adults, due to the impact of hypnotic drugs on sleep architecture, the impact of aging on pharmacokinetics, as well as polypharmacy and drug-to-drug interactions,” Dr. Dix said. She noted that clinical trials of insomnia drugs rarely include geriatric patients.

University of South Carolina

The American Academy of Sleep Medicine recommends CBT-I as first-line treatment for insomnia, with the key benefit being its exemplary safety profile, said Shilpa Srinivasan, MD, a professor of clinical psychiatry at the University of South Carolina, Columbia, who also presented during the session.

“The biggest [attribute] of CBT-I management strategies is the low risk of side effects,” she said. “How many medications can we say that about?”

The CBT-I intervention includes a focus on key components of lifestyle and mental health issues to improve sleep. These include the following:

• Strictly restricting sleep hours for bedtime and arising (with napping discouraged).
• Control of stimulus to disrupt falling asleep.
• Cognitive therapy to identify and replace maladaptive beliefs.
• Control of sleep hygiene for optimal sleep.
• Relaxation training.

Keys to success

Dr. Srinivasan noted one recent study of CBT-I among patients aged 60 and older with insomnia and depression. The 156 participants randomized to receive weekly 120-minute CBT-I sessions over 2 months were significantly less likely to develop new or recurrent major depression versus their counterparts randomized to receive sleep education (hazard ratio, 0.51; P = .02).

However, CBT-I is more labor intensive than medication and requires provider training and motivation, and commitment on the part of the patient, to be successful.

“We really need to ensure that even when patients are receiving pharmacologic interventions for insomnia that we provide psychoeducation. At the end of the day, some of these nonpharmacologic components can make or break the success of pharmacotherapy,” said Dr. Srinivasan.

Whether using CBT-I alone or in combination with pharmacotherapy, the intervention does not necessarily have to include all components to be beneficial, she said.

“I think one of the challenges in incorporating CBT-I is the misconception that it is an all-or-nothing approach wherein every modality must be utilized,” she said. “While multicomponent CBT-I has been shown to be effective, the individual components can be incorporated into patient encounters in a stepped approach.”

Informing patients that they have options other than medications and involving them in decision-making is key, she added.

“In the case of insomnia, this is particularly relevant because of the physical and emotional distress that it causes,” Dr. Srinivasan said. “Patients often seek over-the-counter medications or other nonprescribed agents to try to obtain relief even before seeking treatment in a health care setting. There is less awareness about evidence-based and effective nonpharmacologic treatments such as CBT-I.”

Dr. Tampi, Dr. Dix, and Dr. Srinivasan have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

NEW ORLEANS – Cognitive behavioral therapy (CBT) should be the first-line therapy for insomnia in seniors, but many clinicians are unaware of its benefits, experts say.

Rajesh R. Tampi

“The lack of awareness among clinicians who take care of older adults that CBT for insomnia (CBT-I) is an effective treatment for insomnia is an issue,” Rajesh R. Tampi, MD, professor and chairman of the department of psychiatry, Creighton University, Omaha, Neb., told this news organization.

Dr. Tampi was among the speakers during a session as part of the American Association for Geriatric Psychiatry annual meeting addressing the complex challenges of treating insomnia in older patients, who tend to have higher rates of insomnia than their younger counterparts.

The prevalence of insomnia in older adults is estimated to be 20%-40%, and medication is frequently the first treatment choice, a less than ideal approach, said Dr. Tampi.

“Prescribing sedatives and hypnotics, which can cause severe adverse effects, without a thorough assessment that includes comorbidities that may be causing the insomnia” is among the biggest mistakes clinicians make in the treatment of insomnia in older patients, Dr. Tampi said in an interview.

“It’s our duty as providers to first take a good assessment, talk about polymorbidity, and try to address those conditions, and judiciously use medications in conjunction with at least components of CBT-I,” he said.
 

Long-term safety, efficacy unclear

About one-third of older adults take at least one form of pharmacological treatment for insomnia symptoms, said Ebony Dix, MD, assistant professor of psychiatry at Yale University, New Haven, Conn., in a separate talk during the session. This, despite the low-risk profile of CBT and recommendations from various medical societies that CBT should be tried first.

Dr. Dix noted that medications approved for insomnia by the U.S. Food and Drug Administration, including melatonin receptor agonists, heterocyclics, and dual orexin receptor antagonists (DORAs), can play an important role in the short-term management of insomnia, but their long-term effects are unknown.

“Pharmacotherapeutic agents may be effective in the short term, but there is a lack of sufficient, statistically significant data to support the long-term safety and efficacy of any [sleep] medication, especially in aging adults, due to the impact of hypnotic drugs on sleep architecture, the impact of aging on pharmacokinetics, as well as polypharmacy and drug-to-drug interactions,” Dr. Dix said. She noted that clinical trials of insomnia drugs rarely include geriatric patients.

University of South Carolina

The American Academy of Sleep Medicine recommends CBT-I as first-line treatment for insomnia, with the key benefit being its exemplary safety profile, said Shilpa Srinivasan, MD, a professor of clinical psychiatry at the University of South Carolina, Columbia, who also presented during the session.

“The biggest [attribute] of CBT-I management strategies is the low risk of side effects,” she said. “How many medications can we say that about?”

The CBT-I intervention includes a focus on key components of lifestyle and mental health issues to improve sleep. These include the following:

• Strictly restricting sleep hours for bedtime and arising (with napping discouraged).
• Control of stimulus to disrupt falling asleep.
• Cognitive therapy to identify and replace maladaptive beliefs.
• Control of sleep hygiene for optimal sleep.
• Relaxation training.

Keys to success

Dr. Srinivasan noted one recent study of CBT-I among patients aged 60 and older with insomnia and depression. The 156 participants randomized to receive weekly 120-minute CBT-I sessions over 2 months were significantly less likely to develop new or recurrent major depression versus their counterparts randomized to receive sleep education (hazard ratio, 0.51; P = .02).

However, CBT-I is more labor intensive than medication and requires provider training and motivation, and commitment on the part of the patient, to be successful.

“We really need to ensure that even when patients are receiving pharmacologic interventions for insomnia that we provide psychoeducation. At the end of the day, some of these nonpharmacologic components can make or break the success of pharmacotherapy,” said Dr. Srinivasan.

Whether using CBT-I alone or in combination with pharmacotherapy, the intervention does not necessarily have to include all components to be beneficial, she said.

“I think one of the challenges in incorporating CBT-I is the misconception that it is an all-or-nothing approach wherein every modality must be utilized,” she said. “While multicomponent CBT-I has been shown to be effective, the individual components can be incorporated into patient encounters in a stepped approach.”

Informing patients that they have options other than medications and involving them in decision-making is key, she added.

“In the case of insomnia, this is particularly relevant because of the physical and emotional distress that it causes,” Dr. Srinivasan said. “Patients often seek over-the-counter medications or other nonprescribed agents to try to obtain relief even before seeking treatment in a health care setting. There is less awareness about evidence-based and effective nonpharmacologic treatments such as CBT-I.”

Dr. Tampi, Dr. Dix, and Dr. Srinivasan have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

As the prevalence of obstructive sleep apnea (OSA) has steadily increased in the United States, so has the awareness of central sleep apnea (CSA). The hallmark of CSA is transient cessation of airflow during sleep due to a lack of respiratory effort triggered by the brain. This is in contrast to OSA, in which there is absence of airflow despite continued ventilatory effort due to physical airflow obstruction. The gold standard for the diagnosis and optimal treatment assessment of CSA is inlaboratory polysomnography (PSG) with esophageal manometry, but in practice, respiratory effort is generally estimated through oronasal flow and respiratory inductance plethysmography bands placed on the chest and abdomen during PSG.

Background

The literature has demonstrated a higher prevalence of moderate-to-severe OSA in the general population compared with that of CSA. While OSA is associated with worse clinical outcomes, more evidence is needed on the long-term clinical impact and optimal treatment strategies for CSA.¹ CSA is overrepresented among certain clinical populations. CSA is not frequently diagnosed in the active-duty population, but is increasing in the veteran population, especially in those with heart failure (HF), stroke, neuromuscular disorders, and opioid use. It is associated with increased admissions related to comorbid cardiovascular disorders and to an increased risk of death.^2-4 The clinical concerns with CSA parallel those of OSA. The absence of respiration (apneas and hypopneas due to lack of effort) results in sympathetic surge, compromise of oxygenation and ventilation, sleep fragmentation, and elevation in blood pressure. Symptoms such as excessive daytime sleepiness, morning headaches, witnessed apneas, and nocturnal arrhythmias are shared between the 2 disorders.

Ventilatory instability is the most widely accepted mechanism leading to CSA in patients. Loop gain is the concept used to explain ventilatory control. This feedback loop is influenced by controller gain (primarily represented by central and peripheral chemoreceptors causing changes in ventilation due to PaCO₂ [partial pressure of CO₂ in arterial blood] fluctuations), plant gain (includes lungs and respiratory muscles and their ability to eliminate CO₂), and circulation time (feedback between controller and plant).⁵

High loop gain and narrow CO₂ reserve contribute to ventilatory instability in CSA.⁶ Those with high loop gain have increased sensitivity to changes in CO₂. These patients tend to overbreathe in response to smaller increases in PaCO₂ compared with those with low loop gain. Once the PaCO₂ falls below an individual’s apneic threshold (AT), an apnea will occur.⁷ The brainstem then pauses ventilation to allow the PaCO₂ to rise back above the AT. CSAs also can occur in healthy individuals as they transition from wakefulness into non–rapid eye movement (REM) sleep in a phenomenon called sleep state oscillation, with a mechanism that is similar to hyperventilation-induced CSAs described earlier.

Primary CSA has been defined in the International Classification of Sleep Disorders 3rd edition (ICSD-3) with the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of Cheyne-Stokes breathing (CSB); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) there is no evidence of nocturnal hypoventilation; and (4) the disorder is not better explained by another medical use, substance use disorder (SUD), or other current sleep, medical, or neurologic disorder.⁸

A systematic clinical approach should be used to identify and treat CSA (Figure).^6,7

Nonhypercapnic CSA

Heart Failure–Induced CSA

The leading medical diagnosis causing CSA is congestive HF (CHF), and there is a correlation between HF severity and presence of CSA. In patients with stable CHF with HF reduced ejection fraction (HFrEF), CSA is highly prevalent, occurring in 25% to 40% of patients.⁹ In contrast to other subtypes of CSA where literature regarding prognosis is lacking, the literature is clear that patients with HFrEF with CSA have a worse prognosis, with increased risk of death independent of the severity of HF. This may be the result of CSA promoting malignant ventricular arrhythmias. The prevalence of CSA in HF with preserved ejection fraction (HFpEF) is about 18% to 30%.^10,11

A significant reduction in cardiac output results in circulatory delay between the lungs and chemoreceptors that produces CSB periodic breathing, which is characteristic of the most recognized form of CSA. Per the ICSD-3, CSA with CSB requires the following 4 findings: (1) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; there are at least 3 consecutive CSAs and/or central hypopneas separated by crescendo-decrescendo breathing with a cycle length of at least 40 seconds (ie, CSB pattern), and the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) the breathing pattern is associated with atrial fibrillation/flutter, CHF, or a neurologic disorder; and (4) the disorder is not better explained by another current sleep disorder, medication use (eg, opioids), or SUD.⁸

Treatment of HF-induced CSA begins with guideline-based medical management with the goal of reducing pulmonary capillary wedge pressure or increasing left ventricular ejection fraction through means that may include cardiac resynchronization therapy or left ventricular assist devices, when clinically indicated. If medical optimization is not sufficient, the next step is continuous positive airway pressure (CPAP or PAP), followed by adaptive servo-ventilation (ASV) if the apnea-hypopnea index (AHI) remains > 15 events per hour and is clinically indicated.

ASV is a second-line PAP therapy modality that uses proprietary algorithms to provide variable amounts of pressure that alternate between expiratory and inspiratory phases of the respiratory cycle in combination with physician-set or automatic backup respiratory rate designed to stabilize ventilation in patients with CSA and CSB. The inability to adjust tidal volume, potentially resulting in insufficient tidal volumes or ventilation, results in the contraindication for its use in patients with CSA with comorbid conditions that may result in hypercapnic respiratory failure. These conditions include chronic hypoventilation in obesity hypoventilation syndrome (OHS), moderate-to-severe chronic obstructive pulmonary disease, chronic elevation of PaCO₂ on arterial blood gas > 45 mm Hg, and restrictive thoracic or neuromuscular disease.¹²

Although ASV is more effective in normalizing AHI in patients with HF and CSA than is CPAP therapy, the clinical indications for ASV in the setting of HFrEF changed drastically with the publication of the landmark SERVE-HF trial, which investigated the effects of adding ASV to guideline-based medical management on survival and cardiovascular outcomes in patients with HFrEF and predominant CSA.¹³ The study did not show a difference between the ASV and control groups for the primary endpoint: a composite of time to first event of death from any cause, lifesaving cardiovascular intervention (transplantation, implantation of a long-term ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization for worsening HF. However, the study showed a statistically and clinically significant increased risk of all-cause and cardiovascular mortality in the ASV group compared with the control group.¹³ A possible explanation for the increased all-cause and cardiovascular mortality is that CSA potentially serves a protective mechanism that when eliminated results in deleterious clinical outcomes. This resulted in significant changes in the treatment algorithm for HF-induced CSA with left ventricular ejection fraction of at least 45% becoming the cutoff for therapeutic decisions.

Treatment-Emergent CSA

Treatment-emergent CSA (TECSA, also known as complex sleep apnea) has been defined by the ICSD-3 by the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of predominantly obstructive events; (2) resolution of obstructive events with PAP without a backup rate and CSA index (CAI) ≥ 5 per hour with central events ≥ 50% of the AHI; and (3) CSA not better explained by another disorder.⁸ Patients with TECSA can be further classified into those who have transient events that resolve within weeks to months, those with persistent events, and those with delayed events that may develop weeks to months after initiating PAP therapy.¹⁴

PAP treatment can decrease the PaCO₂ below the AT due to removal of flow limitation in previously obstructed upper airways, resulting in TECSA.^15,16 PAP therapy has not been the only treatment where new CSA has been identified on initiation. A 2021 systematic review identified patients who developed new-onset CSA with mandibular advancement device (MAD), hypoglossal nerve stimulator, tongue protrusion device, and nasal expiratory PAP device use, as well as after tracheostomy, maxillofacial surgery, and other surgeries, such as nasal and uvulopalatopharyngoplasty.¹⁷

The prevalence of TECSA has been noted to range between 0.6% and 20.3%, but Nigam and colleagues estimated a prevalence of 8.4% in their systematic review.^11,14 The variability in prevalence between studies could be due to differences in study design (retrospective vs prospective vs cross-sectional), diagnostic and inclusion criteria, patient population, and type of study used (full-night vs split-night vs both).^18,19 Risk factors for TECSA include male sex; older age; lower body mass index; higher baseline AHI, CAI, and arousal index; chronic medical issues such as CHF and coronary artery disease; opioid use; higher CPAP settings; excessive mask leak; and bilevel PAP (BiPAP) use.²⁰ Identifying these risk factors is important, as patients with TECSA are at higher risk of discontinuing therapy and of developing PAP intolerance.^15,20

Most patients with TECSA can continue CPAP therapy with resolution of events over weeks to months, but treatment of comorbid conditions should be optimized as they could be contributing factors. Zeineddine and colleagues recommend continuation of CPAP for 3 months if the patient has minor or no symptoms.¹⁹ A 2018 systematic review noted that 14.3% to 46.2% of TECSA patients will have persistent TECSA and some will develop TECSA after at least 1 month of PAP therapy.¹⁴ For these patients and those with severe symptoms in spite of therapy, a switch to BiPAP spontaneous/timed (BiPAP-S/T) or ASV should be considered, if not contraindicated based on comorbidities.²¹ Medications such as acetazolamide, oxygen therapy, and CO₂ supplementation have also been discussed as alternative treatments, but these options should not be first-line therapies and should be used on a case-by-case basis as adjuncts to PAP therapy.^16,17

Altitude-Induced CSA

Also known as CSA due to high-altitude periodic breathing (CSA-HAPB), this form of CSA occurs in nearly all lowlanders at altitudes above 3000 m, with severity increasing with altitude.¹⁵ The exact altitude at which it occurs varies based on an individual’s physiology. CSA-HAPB occurs in response to the low barometric pressure at altitude, combined with stable fraction of oxygen, resulting in decreased inspired partial pressure of oxygen and hypoxia. The normal physiologic response to hypoxia is increased ventilation, which can cause hypocapnia, suppressing respiratory drive and resulting in CSAs. The instability of the respiratory response results in cyclical CSAs followed by hyperventilation. This periodic breathing then causes arousals from sleep, driving further sleep fragmentation and exacerbation of baseline desaturation and instability in the cyclical respiratory response. There is individual variability in hypoxic chemoresponsiveness (loop gain). Compensatory mechanisms are most robust when an individual routinely dwells at high altitude, resulting in acclimatization, rather than traveling there for a brief stay. Genetics and cardiac output also contribute to the effectiveness of compensation to altitude.

CSA-HAPB is defined by the following ICSD-3 criteria: (1) Recent ascent to a high altitude (typically ≥ 2500 m, although some individuals may exhibit the disorder at altitudes as low as 1500 m); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) symptoms are clinically attributable to HAPB, or PSG, if performed, reveals recurrent CSAs or hypopneas primarily during non-REM sleep at a frequency of ≥ 5 events per hour; (4) the disorder is not better explained by another current sleep disorder, medical or neurological disorder, medication use (eg, narcotics), or SUD.⁸

Treatment options to improve nocturnal oxygen saturation and reduce or eliminate CSA-HAPB in nonacclimatized individuals include oxygen-enriched air, acetazolamide, or combination treatment with acetazolamide and automatic PAP (APAP).²² A meta-analysis looking at the effectiveness of acetazolamide in 8 different randomized controlled trials demonstrated that a dose of 250 mg per day was effective in improving sleep apnea at altitude as measured by a decrease in AHI, decrease in percentage of periodic breathing, and increasing oxygenation during sleep.¹⁵ The question of superiority of combined acetazolamide with APAP to placebo with APAP in treatment of high-altitude OSA was addressed in a randomized double-blind, placebo-controlled trial. The results showed that combined APAP (5-15 cm of water pressure) and acetazolamide (250 mg morning, 500 mg evening) decreased the AHI to normal range, whereas central events persisted in the APAP and placebo group.²³ In addition, Latshang and colleagues have demonstrated that ASV may not be as efficacious for controlling CSA-HAPB in nonacclimatized individuals compared with oxygen therapy and suggested that further research is warranted examining if ASV device algorithm adjustment improves efficacy of this therapeutic option.²⁴

Comorbidity-Induced CSA

Several medical conditions may be associated with CSA, including chronic kidney disease (CKD), pulmonary hypertension, acromegaly, and hypothyroidism. The common pathophysiologic link is that these disorders may result in alteration of ventilatory responses to CO₂, ultimately resulting in CSA.

As many as 10% of patients with CKD may experience CSA.^25,26 The complications encountered in CKD include fluid overload with pulmonary edema, chronic metabolic acidosis, and anemia. These can provoke hyperventilation in addition to poor sleep quality, triggering arousals that further drive CSA in these patients. Additional risk factors for CSA in this population include atrial fibrillation and cardiac dysfunction. Clinical interventions that have demonstrated reduction in CSA include hemodialysis at night vs daytime and using bicarbonate buffer vs acetate for hemodialysis ^22-24,26-29

Hypersecretion of growth hormone in acromegaly also results in hyperventilation contributing to CSA. While medical and surgical management of acromegaly results in a reduction in OSA, there is limited evidence on the outcome of the CSA after these interventions.

Hypothyroidism and CSA both present with similar symptoms of fatigue, daytime sleepiness, depression, and headaches. Studies suggest that respiratory muscle fatigue and decreased ventilatory response to hypercapnia and hypoxia contribute to apnea in this population. In one study, 27% of hypothyroid patients had a blunted response to hypercapnia, and 34% suffered from a blunted response to hypoxia. The same study showed universal reversal of the impairment following thyroid replacement therapy and return to euthyroid state.³⁰ Similarly, multiple studies have shown reversal of respiratory muscle fatigue after initiation of thyroid replacement.^30-32 Assessing thyroid function is an appropriate initial step during any sleep-disordered breathing workup, as it is a reversible cause of apnea. Up to 2.4% of patients presenting for PSG (and diagnosed with OSA) are found to have undiagnosed hypothyroidism.^32,33 In a military population, treatment of a secondary cause of CSA, such as hypothyroidism, could remove some administrative burden as well as improve service members’ quality of life.

If CSA persists despite previous treatment strategies, then clinicians should focus on the optimization of treatment for comorbid conditions. If that does not resolve CSA, CPAP should be used when AHI remains above 15 events per hour or ASV can be used.

Idiopathic CSA

There are limited data on the pathophysiology and prevalence of idiopathic CSA. In most cases it is hypocapnic CSA, which occurs after an arousal from sleep causing hyperventilation that causes hypocapnia below the apnea threshold similar to CSA-HAPB. Therapeutic options based on addressing underlying pathophysiology include increasing CO₂ by inhalation or addition of dead space. Additional therapeutic options to reduce the arousals and CSAs include hypnotics, such as zolpidem and acetazolamide, but these should be administered only with close clinical monitoring.If symptoms continue, CPAP or ASV may be trialed; however, limited clinical evidence of efficacy exists.¹⁵

For patients with moderate-to-severe CSA, an additional treatment option includes an implantable device (eg, Zoll remede¯), which stimulates the phrenic nerve to move the diaphragm and restore normal breathing. This device is not indicated for those with OSA. Based on data submitted to the US Food and Drug Administration, AHI is reduced by ≥ 50% in 51% of patients with the implanted device and by 11% in patients without the device. Five-year follow-up data show sustained improvements.³⁴

Hypercapnic CSA

CSA due to a medication or substance requires the following criteria: (1) the patient is taking an opioid or other respiratory depressant; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia (difficulty initiating or maintaining sleep, frequent awakenings, or nonrestorative sleep); (3) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of CSB; and (4) the disorder is not better explained by another current sleep disorder.⁸

Drugs that affect the respiratory centers, such as opiates and opioids, γ aminobutyric acid (GABA) type A and B receptor agonists, and P2Y(12) receptor antagonists such as ticagrelor, may result in alterations in ventilatory drive in the central nervous system respiratory centers, resulting in CSA.

Opioids are prescribed either for chronic pain or to treat opiate addiction with methadone, resulting in about one-third of chronic opioid users having some form of CSA.³⁵ CSA may be seen after opioids have been used for at least 2 months. A dose-dependent effect exists with high doses of opioids, typically resulting in hypoventilation, hypercapnia, and hypoxemia with ataxic or erratic breathing and a periodic breathing pattern similar to those described in CSA-HAPB or idiopathic CSA. About 14% to 60% of methadone patients also demonstrate CSA or ataxic breathing.^35,36

Benzodiazepines (GABA-A receptor agonists) and baclofen (a GABA-B receptor agonist) depress central ventilatory drive, blunt the response to hypoxia and hypercapnia, leading to CSAs, and increase risk for OSA by increasing upper airway obstruction through reduction in tone. Use of these medications with antidepressants or opioids further exacerbates this response.

Unlike the other medications previously described, ticagrelor, a first-line dual antiplatelet therapy medication indicated for acute coronary syndrome treatment, actually increases the activity of the respiratory centers but may result in CSA.

First-line treatment, if possible, is reduction in medication dose or complete withdrawal. Additional treatment options include PAP therapies: CPAP, BiPAP, ASV, and oxygen therapy with or without PAP.^37,38 The literature has demonstrated that for the treatment of opioid-associated CSA, ASV (in cases of normocapnia) and noninvasive ventilation (NIV)/BiPAP (in cases with hypercapnia or REM sleep hypoventilation) are superior treatment options when compared with conventional CPAP for elimination of respiratory events. CPAP with oxygen therapy and BiPAP with oxygen therapy are more effective than CPAP alone in reducing respiratory events. However, concerns remain that as with CSA in HF, CSA in chronic opioid users may serve as a physiologic protective mechanism to prevent further clinical injury from opioids. Similarly, as in the use of ASV in the SERVE-HF trial, focusing on elimination of respiratory events may prove detrimental. More studies are needed to determine whether reducing the number of CSA events in chronic opioid users is clinically beneficial when other health outcomes, such as cardiovascular, neurocognitive, hospital/intensive care unit admissions, and mortality risks are examined.

Neuromuscular-Induced CSA

CSA also is highly prevalent in neuromuscular conditions, such as amyotrophic lateral sclerosis, Duchenne muscular dystrophy, myotonic dystrophy, advanced multiple sclerosis, and acid maltase deficiency. There is reduced respiratory muscle strength and tone in these disorders, resulting in alveolar hypoventilation with hypercapnia. Given the hypercapnia, NIV/BiPAP is the first-line treatment to improve survival, gas exchange, symptom burden, and quality of life.

Stroke-Induced CSA

Extensive cerebrovascular events commonly precipitate sleep-related breathing disorders. The incidence increases in the acute phase of stroke and decreases 3 to 6 months poststroke; however, incidence also depends on the severity of the stroke.^7,39,40 Stroke also has been shown to be a predictor of CSA (odds ratio, 1.65; 95% CI, 1.50-1.82; P < .001) in a retrospective analysis of a large cohort of US veterans.² The location of the lesion often determines whether normocapnic or hypercapnic CSA will predominate, based on ventilatory instability resulting in normocapnia or reduced ventilatory drive resulting in hypercapnic CSA. PSG results and blood gases direct the treatment options. CSA with normocapnia is treated with ASV, and patients with hypercapnia/REM sleep hypoventilation are treated with NIV/BiPAP.

Conclusions

While much has been learned about CSA in recent decades, more evidence needs to be gathered to determine optimal treatment strategies and the impact on patient prognosis. The identification of CSA can lead to the diagnosis of previously unrecognized medical conditions. With proper diagnosis and treatment, we can optimize clinical management and improve patients’ prognosis and quality of life.

Acknowledgments

The authors thank the librarians of the Franzello Aeromedical Library in particular Sara Craycraft, Catherine Stahl, Kristen Young and Elizabeth Irvine for their support of this publication.

As the prevalence of obstructive sleep apnea (OSA) has steadily increased in the United States, so has the awareness of central sleep apnea (CSA). The hallmark of CSA is transient cessation of airflow during sleep due to a lack of respiratory effort triggered by the brain. This is in contrast to OSA, in which there is absence of airflow despite continued ventilatory effort due to physical airflow obstruction. The gold standard for the diagnosis and optimal treatment assessment of CSA is inlaboratory polysomnography (PSG) with esophageal manometry, but in practice, respiratory effort is generally estimated through oronasal flow and respiratory inductance plethysmography bands placed on the chest and abdomen during PSG.

Background

The literature has demonstrated a higher prevalence of moderate-to-severe OSA in the general population compared with that of CSA. While OSA is associated with worse clinical outcomes, more evidence is needed on the long-term clinical impact and optimal treatment strategies for CSA.¹ CSA is overrepresented among certain clinical populations. CSA is not frequently diagnosed in the active-duty population, but is increasing in the veteran population, especially in those with heart failure (HF), stroke, neuromuscular disorders, and opioid use. It is associated with increased admissions related to comorbid cardiovascular disorders and to an increased risk of death.^2-4 The clinical concerns with CSA parallel those of OSA. The absence of respiration (apneas and hypopneas due to lack of effort) results in sympathetic surge, compromise of oxygenation and ventilation, sleep fragmentation, and elevation in blood pressure. Symptoms such as excessive daytime sleepiness, morning headaches, witnessed apneas, and nocturnal arrhythmias are shared between the 2 disorders.

Ventilatory instability is the most widely accepted mechanism leading to CSA in patients. Loop gain is the concept used to explain ventilatory control. This feedback loop is influenced by controller gain (primarily represented by central and peripheral chemoreceptors causing changes in ventilation due to PaCO₂ [partial pressure of CO₂ in arterial blood] fluctuations), plant gain (includes lungs and respiratory muscles and their ability to eliminate CO₂), and circulation time (feedback between controller and plant).⁵

High loop gain and narrow CO₂ reserve contribute to ventilatory instability in CSA.⁶ Those with high loop gain have increased sensitivity to changes in CO₂. These patients tend to overbreathe in response to smaller increases in PaCO₂ compared with those with low loop gain. Once the PaCO₂ falls below an individual’s apneic threshold (AT), an apnea will occur.⁷ The brainstem then pauses ventilation to allow the PaCO₂ to rise back above the AT. CSAs also can occur in healthy individuals as they transition from wakefulness into non–rapid eye movement (REM) sleep in a phenomenon called sleep state oscillation, with a mechanism that is similar to hyperventilation-induced CSAs described earlier.

Primary CSA has been defined in the International Classification of Sleep Disorders 3rd edition (ICSD-3) with the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of Cheyne-Stokes breathing (CSB); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) there is no evidence of nocturnal hypoventilation; and (4) the disorder is not better explained by another medical use, substance use disorder (SUD), or other current sleep, medical, or neurologic disorder.⁸

A systematic clinical approach should be used to identify and treat CSA (Figure).^6,7

Nonhypercapnic CSA

Heart Failure–Induced CSA

The leading medical diagnosis causing CSA is congestive HF (CHF), and there is a correlation between HF severity and presence of CSA. In patients with stable CHF with HF reduced ejection fraction (HFrEF), CSA is highly prevalent, occurring in 25% to 40% of patients.⁹ In contrast to other subtypes of CSA where literature regarding prognosis is lacking, the literature is clear that patients with HFrEF with CSA have a worse prognosis, with increased risk of death independent of the severity of HF. This may be the result of CSA promoting malignant ventricular arrhythmias. The prevalence of CSA in HF with preserved ejection fraction (HFpEF) is about 18% to 30%.^10,11

A significant reduction in cardiac output results in circulatory delay between the lungs and chemoreceptors that produces CSB periodic breathing, which is characteristic of the most recognized form of CSA. Per the ICSD-3, CSA with CSB requires the following 4 findings: (1) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; there are at least 3 consecutive CSAs and/or central hypopneas separated by crescendo-decrescendo breathing with a cycle length of at least 40 seconds (ie, CSB pattern), and the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) the breathing pattern is associated with atrial fibrillation/flutter, CHF, or a neurologic disorder; and (4) the disorder is not better explained by another current sleep disorder, medication use (eg, opioids), or SUD.⁸

Treatment of HF-induced CSA begins with guideline-based medical management with the goal of reducing pulmonary capillary wedge pressure or increasing left ventricular ejection fraction through means that may include cardiac resynchronization therapy or left ventricular assist devices, when clinically indicated. If medical optimization is not sufficient, the next step is continuous positive airway pressure (CPAP or PAP), followed by adaptive servo-ventilation (ASV) if the apnea-hypopnea index (AHI) remains > 15 events per hour and is clinically indicated.

ASV is a second-line PAP therapy modality that uses proprietary algorithms to provide variable amounts of pressure that alternate between expiratory and inspiratory phases of the respiratory cycle in combination with physician-set or automatic backup respiratory rate designed to stabilize ventilation in patients with CSA and CSB. The inability to adjust tidal volume, potentially resulting in insufficient tidal volumes or ventilation, results in the contraindication for its use in patients with CSA with comorbid conditions that may result in hypercapnic respiratory failure. These conditions include chronic hypoventilation in obesity hypoventilation syndrome (OHS), moderate-to-severe chronic obstructive pulmonary disease, chronic elevation of PaCO₂ on arterial blood gas > 45 mm Hg, and restrictive thoracic or neuromuscular disease.¹²

Although ASV is more effective in normalizing AHI in patients with HF and CSA than is CPAP therapy, the clinical indications for ASV in the setting of HFrEF changed drastically with the publication of the landmark SERVE-HF trial, which investigated the effects of adding ASV to guideline-based medical management on survival and cardiovascular outcomes in patients with HFrEF and predominant CSA.¹³ The study did not show a difference between the ASV and control groups for the primary endpoint: a composite of time to first event of death from any cause, lifesaving cardiovascular intervention (transplantation, implantation of a long-term ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization for worsening HF. However, the study showed a statistically and clinically significant increased risk of all-cause and cardiovascular mortality in the ASV group compared with the control group.¹³ A possible explanation for the increased all-cause and cardiovascular mortality is that CSA potentially serves a protective mechanism that when eliminated results in deleterious clinical outcomes. This resulted in significant changes in the treatment algorithm for HF-induced CSA with left ventricular ejection fraction of at least 45% becoming the cutoff for therapeutic decisions.

Treatment-Emergent CSA

Treatment-emergent CSA (TECSA, also known as complex sleep apnea) has been defined by the ICSD-3 by the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of predominantly obstructive events; (2) resolution of obstructive events with PAP without a backup rate and CSA index (CAI) ≥ 5 per hour with central events ≥ 50% of the AHI; and (3) CSA not better explained by another disorder.⁸ Patients with TECSA can be further classified into those who have transient events that resolve within weeks to months, those with persistent events, and those with delayed events that may develop weeks to months after initiating PAP therapy.¹⁴

PAP treatment can decrease the PaCO₂ below the AT due to removal of flow limitation in previously obstructed upper airways, resulting in TECSA.^15,16 PAP therapy has not been the only treatment where new CSA has been identified on initiation. A 2021 systematic review identified patients who developed new-onset CSA with mandibular advancement device (MAD), hypoglossal nerve stimulator, tongue protrusion device, and nasal expiratory PAP device use, as well as after tracheostomy, maxillofacial surgery, and other surgeries, such as nasal and uvulopalatopharyngoplasty.¹⁷

The prevalence of TECSA has been noted to range between 0.6% and 20.3%, but Nigam and colleagues estimated a prevalence of 8.4% in their systematic review.^11,14 The variability in prevalence between studies could be due to differences in study design (retrospective vs prospective vs cross-sectional), diagnostic and inclusion criteria, patient population, and type of study used (full-night vs split-night vs both).^18,19 Risk factors for TECSA include male sex; older age; lower body mass index; higher baseline AHI, CAI, and arousal index; chronic medical issues such as CHF and coronary artery disease; opioid use; higher CPAP settings; excessive mask leak; and bilevel PAP (BiPAP) use.²⁰ Identifying these risk factors is important, as patients with TECSA are at higher risk of discontinuing therapy and of developing PAP intolerance.^15,20

Most patients with TECSA can continue CPAP therapy with resolution of events over weeks to months, but treatment of comorbid conditions should be optimized as they could be contributing factors. Zeineddine and colleagues recommend continuation of CPAP for 3 months if the patient has minor or no symptoms.¹⁹ A 2018 systematic review noted that 14.3% to 46.2% of TECSA patients will have persistent TECSA and some will develop TECSA after at least 1 month of PAP therapy.¹⁴ For these patients and those with severe symptoms in spite of therapy, a switch to BiPAP spontaneous/timed (BiPAP-S/T) or ASV should be considered, if not contraindicated based on comorbidities.²¹ Medications such as acetazolamide, oxygen therapy, and CO₂ supplementation have also been discussed as alternative treatments, but these options should not be first-line therapies and should be used on a case-by-case basis as adjuncts to PAP therapy.^16,17

Altitude-Induced CSA

Also known as CSA due to high-altitude periodic breathing (CSA-HAPB), this form of CSA occurs in nearly all lowlanders at altitudes above 3000 m, with severity increasing with altitude.¹⁵ The exact altitude at which it occurs varies based on an individual’s physiology. CSA-HAPB occurs in response to the low barometric pressure at altitude, combined with stable fraction of oxygen, resulting in decreased inspired partial pressure of oxygen and hypoxia. The normal physiologic response to hypoxia is increased ventilation, which can cause hypocapnia, suppressing respiratory drive and resulting in CSAs. The instability of the respiratory response results in cyclical CSAs followed by hyperventilation. This periodic breathing then causes arousals from sleep, driving further sleep fragmentation and exacerbation of baseline desaturation and instability in the cyclical respiratory response. There is individual variability in hypoxic chemoresponsiveness (loop gain). Compensatory mechanisms are most robust when an individual routinely dwells at high altitude, resulting in acclimatization, rather than traveling there for a brief stay. Genetics and cardiac output also contribute to the effectiveness of compensation to altitude.

CSA-HAPB is defined by the following ICSD-3 criteria: (1) Recent ascent to a high altitude (typically ≥ 2500 m, although some individuals may exhibit the disorder at altitudes as low as 1500 m); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) symptoms are clinically attributable to HAPB, or PSG, if performed, reveals recurrent CSAs or hypopneas primarily during non-REM sleep at a frequency of ≥ 5 events per hour; (4) the disorder is not better explained by another current sleep disorder, medical or neurological disorder, medication use (eg, narcotics), or SUD.⁸

Treatment options to improve nocturnal oxygen saturation and reduce or eliminate CSA-HAPB in nonacclimatized individuals include oxygen-enriched air, acetazolamide, or combination treatment with acetazolamide and automatic PAP (APAP).²² A meta-analysis looking at the effectiveness of acetazolamide in 8 different randomized controlled trials demonstrated that a dose of 250 mg per day was effective in improving sleep apnea at altitude as measured by a decrease in AHI, decrease in percentage of periodic breathing, and increasing oxygenation during sleep.¹⁵ The question of superiority of combined acetazolamide with APAP to placebo with APAP in treatment of high-altitude OSA was addressed in a randomized double-blind, placebo-controlled trial. The results showed that combined APAP (5-15 cm of water pressure) and acetazolamide (250 mg morning, 500 mg evening) decreased the AHI to normal range, whereas central events persisted in the APAP and placebo group.²³ In addition, Latshang and colleagues have demonstrated that ASV may not be as efficacious for controlling CSA-HAPB in nonacclimatized individuals compared with oxygen therapy and suggested that further research is warranted examining if ASV device algorithm adjustment improves efficacy of this therapeutic option.²⁴

Comorbidity-Induced CSA

Several medical conditions may be associated with CSA, including chronic kidney disease (CKD), pulmonary hypertension, acromegaly, and hypothyroidism. The common pathophysiologic link is that these disorders may result in alteration of ventilatory responses to CO₂, ultimately resulting in CSA.

As many as 10% of patients with CKD may experience CSA.^25,26 The complications encountered in CKD include fluid overload with pulmonary edema, chronic metabolic acidosis, and anemia. These can provoke hyperventilation in addition to poor sleep quality, triggering arousals that further drive CSA in these patients. Additional risk factors for CSA in this population include atrial fibrillation and cardiac dysfunction. Clinical interventions that have demonstrated reduction in CSA include hemodialysis at night vs daytime and using bicarbonate buffer vs acetate for hemodialysis ^22-24,26-29

Hypersecretion of growth hormone in acromegaly also results in hyperventilation contributing to CSA. While medical and surgical management of acromegaly results in a reduction in OSA, there is limited evidence on the outcome of the CSA after these interventions.

Hypothyroidism and CSA both present with similar symptoms of fatigue, daytime sleepiness, depression, and headaches. Studies suggest that respiratory muscle fatigue and decreased ventilatory response to hypercapnia and hypoxia contribute to apnea in this population. In one study, 27% of hypothyroid patients had a blunted response to hypercapnia, and 34% suffered from a blunted response to hypoxia. The same study showed universal reversal of the impairment following thyroid replacement therapy and return to euthyroid state.³⁰ Similarly, multiple studies have shown reversal of respiratory muscle fatigue after initiation of thyroid replacement.^30-32 Assessing thyroid function is an appropriate initial step during any sleep-disordered breathing workup, as it is a reversible cause of apnea. Up to 2.4% of patients presenting for PSG (and diagnosed with OSA) are found to have undiagnosed hypothyroidism.^32,33 In a military population, treatment of a secondary cause of CSA, such as hypothyroidism, could remove some administrative burden as well as improve service members’ quality of life.

If CSA persists despite previous treatment strategies, then clinicians should focus on the optimization of treatment for comorbid conditions. If that does not resolve CSA, CPAP should be used when AHI remains above 15 events per hour or ASV can be used.

Idiopathic CSA

There are limited data on the pathophysiology and prevalence of idiopathic CSA. In most cases it is hypocapnic CSA, which occurs after an arousal from sleep causing hyperventilation that causes hypocapnia below the apnea threshold similar to CSA-HAPB. Therapeutic options based on addressing underlying pathophysiology include increasing CO₂ by inhalation or addition of dead space. Additional therapeutic options to reduce the arousals and CSAs include hypnotics, such as zolpidem and acetazolamide, but these should be administered only with close clinical monitoring.If symptoms continue, CPAP or ASV may be trialed; however, limited clinical evidence of efficacy exists.¹⁵

For patients with moderate-to-severe CSA, an additional treatment option includes an implantable device (eg, Zoll remede¯), which stimulates the phrenic nerve to move the diaphragm and restore normal breathing. This device is not indicated for those with OSA. Based on data submitted to the US Food and Drug Administration, AHI is reduced by ≥ 50% in 51% of patients with the implanted device and by 11% in patients without the device. Five-year follow-up data show sustained improvements.³⁴

Hypercapnic CSA

CSA due to a medication or substance requires the following criteria: (1) the patient is taking an opioid or other respiratory depressant; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia (difficulty initiating or maintaining sleep, frequent awakenings, or nonrestorative sleep); (3) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of CSB; and (4) the disorder is not better explained by another current sleep disorder.⁸

Drugs that affect the respiratory centers, such as opiates and opioids, γ aminobutyric acid (GABA) type A and B receptor agonists, and P2Y(12) receptor antagonists such as ticagrelor, may result in alterations in ventilatory drive in the central nervous system respiratory centers, resulting in CSA.

Opioids are prescribed either for chronic pain or to treat opiate addiction with methadone, resulting in about one-third of chronic opioid users having some form of CSA.³⁵ CSA may be seen after opioids have been used for at least 2 months. A dose-dependent effect exists with high doses of opioids, typically resulting in hypoventilation, hypercapnia, and hypoxemia with ataxic or erratic breathing and a periodic breathing pattern similar to those described in CSA-HAPB or idiopathic CSA. About 14% to 60% of methadone patients also demonstrate CSA or ataxic breathing.^35,36

Benzodiazepines (GABA-A receptor agonists) and baclofen (a GABA-B receptor agonist) depress central ventilatory drive, blunt the response to hypoxia and hypercapnia, leading to CSAs, and increase risk for OSA by increasing upper airway obstruction through reduction in tone. Use of these medications with antidepressants or opioids further exacerbates this response.

Unlike the other medications previously described, ticagrelor, a first-line dual antiplatelet therapy medication indicated for acute coronary syndrome treatment, actually increases the activity of the respiratory centers but may result in CSA.

First-line treatment, if possible, is reduction in medication dose or complete withdrawal. Additional treatment options include PAP therapies: CPAP, BiPAP, ASV, and oxygen therapy with or without PAP.^37,38 The literature has demonstrated that for the treatment of opioid-associated CSA, ASV (in cases of normocapnia) and noninvasive ventilation (NIV)/BiPAP (in cases with hypercapnia or REM sleep hypoventilation) are superior treatment options when compared with conventional CPAP for elimination of respiratory events. CPAP with oxygen therapy and BiPAP with oxygen therapy are more effective than CPAP alone in reducing respiratory events. However, concerns remain that as with CSA in HF, CSA in chronic opioid users may serve as a physiologic protective mechanism to prevent further clinical injury from opioids. Similarly, as in the use of ASV in the SERVE-HF trial, focusing on elimination of respiratory events may prove detrimental. More studies are needed to determine whether reducing the number of CSA events in chronic opioid users is clinically beneficial when other health outcomes, such as cardiovascular, neurocognitive, hospital/intensive care unit admissions, and mortality risks are examined.

Neuromuscular-Induced CSA

CSA also is highly prevalent in neuromuscular conditions, such as amyotrophic lateral sclerosis, Duchenne muscular dystrophy, myotonic dystrophy, advanced multiple sclerosis, and acid maltase deficiency. There is reduced respiratory muscle strength and tone in these disorders, resulting in alveolar hypoventilation with hypercapnia. Given the hypercapnia, NIV/BiPAP is the first-line treatment to improve survival, gas exchange, symptom burden, and quality of life.

Stroke-Induced CSA

Extensive cerebrovascular events commonly precipitate sleep-related breathing disorders. The incidence increases in the acute phase of stroke and decreases 3 to 6 months poststroke; however, incidence also depends on the severity of the stroke.^7,39,40 Stroke also has been shown to be a predictor of CSA (odds ratio, 1.65; 95% CI, 1.50-1.82; P < .001) in a retrospective analysis of a large cohort of US veterans.² The location of the lesion often determines whether normocapnic or hypercapnic CSA will predominate, based on ventilatory instability resulting in normocapnia or reduced ventilatory drive resulting in hypercapnic CSA. PSG results and blood gases direct the treatment options. CSA with normocapnia is treated with ASV, and patients with hypercapnia/REM sleep hypoventilation are treated with NIV/BiPAP.

Conclusions

While much has been learned about CSA in recent decades, more evidence needs to be gathered to determine optimal treatment strategies and the impact on patient prognosis. The identification of CSA can lead to the diagnosis of previously unrecognized medical conditions. With proper diagnosis and treatment, we can optimize clinical management and improve patients’ prognosis and quality of life.

Acknowledgments

The authors thank the librarians of the Franzello Aeromedical Library in particular Sara Craycraft, Catherine Stahl, Kristen Young and Elizabeth Irvine for their support of this publication.

As the prevalence of obstructive sleep apnea (OSA) has steadily increased in the United States, so has the awareness of central sleep apnea (CSA). The hallmark of CSA is transient cessation of airflow during sleep due to a lack of respiratory effort triggered by the brain. This is in contrast to OSA, in which there is absence of airflow despite continued ventilatory effort due to physical airflow obstruction. The gold standard for the diagnosis and optimal treatment assessment of CSA is inlaboratory polysomnography (PSG) with esophageal manometry, but in practice, respiratory effort is generally estimated through oronasal flow and respiratory inductance plethysmography bands placed on the chest and abdomen during PSG.

Background

The literature has demonstrated a higher prevalence of moderate-to-severe OSA in the general population compared with that of CSA. While OSA is associated with worse clinical outcomes, more evidence is needed on the long-term clinical impact and optimal treatment strategies for CSA.¹ CSA is overrepresented among certain clinical populations. CSA is not frequently diagnosed in the active-duty population, but is increasing in the veteran population, especially in those with heart failure (HF), stroke, neuromuscular disorders, and opioid use. It is associated with increased admissions related to comorbid cardiovascular disorders and to an increased risk of death.^2-4 The clinical concerns with CSA parallel those of OSA. The absence of respiration (apneas and hypopneas due to lack of effort) results in sympathetic surge, compromise of oxygenation and ventilation, sleep fragmentation, and elevation in blood pressure. Symptoms such as excessive daytime sleepiness, morning headaches, witnessed apneas, and nocturnal arrhythmias are shared between the 2 disorders.

Ventilatory instability is the most widely accepted mechanism leading to CSA in patients. Loop gain is the concept used to explain ventilatory control. This feedback loop is influenced by controller gain (primarily represented by central and peripheral chemoreceptors causing changes in ventilation due to PaCO₂ [partial pressure of CO₂ in arterial blood] fluctuations), plant gain (includes lungs and respiratory muscles and their ability to eliminate CO₂), and circulation time (feedback between controller and plant).⁵

High loop gain and narrow CO₂ reserve contribute to ventilatory instability in CSA.⁶ Those with high loop gain have increased sensitivity to changes in CO₂. These patients tend to overbreathe in response to smaller increases in PaCO₂ compared with those with low loop gain. Once the PaCO₂ falls below an individual’s apneic threshold (AT), an apnea will occur.⁷ The brainstem then pauses ventilation to allow the PaCO₂ to rise back above the AT. CSAs also can occur in healthy individuals as they transition from wakefulness into non–rapid eye movement (REM) sleep in a phenomenon called sleep state oscillation, with a mechanism that is similar to hyperventilation-induced CSAs described earlier.

Primary CSA has been defined in the International Classification of Sleep Disorders 3rd edition (ICSD-3) with the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of Cheyne-Stokes breathing (CSB); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) there is no evidence of nocturnal hypoventilation; and (4) the disorder is not better explained by another medical use, substance use disorder (SUD), or other current sleep, medical, or neurologic disorder.⁸

A systematic clinical approach should be used to identify and treat CSA (Figure).^6,7

Nonhypercapnic CSA

Heart Failure–Induced CSA

The leading medical diagnosis causing CSA is congestive HF (CHF), and there is a correlation between HF severity and presence of CSA. In patients with stable CHF with HF reduced ejection fraction (HFrEF), CSA is highly prevalent, occurring in 25% to 40% of patients.⁹ In contrast to other subtypes of CSA where literature regarding prognosis is lacking, the literature is clear that patients with HFrEF with CSA have a worse prognosis, with increased risk of death independent of the severity of HF. This may be the result of CSA promoting malignant ventricular arrhythmias. The prevalence of CSA in HF with preserved ejection fraction (HFpEF) is about 18% to 30%.^10,11

A significant reduction in cardiac output results in circulatory delay between the lungs and chemoreceptors that produces CSB periodic breathing, which is characteristic of the most recognized form of CSA. Per the ICSD-3, CSA with CSB requires the following 4 findings: (1) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; there are at least 3 consecutive CSAs and/or central hypopneas separated by crescendo-decrescendo breathing with a cycle length of at least 40 seconds (ie, CSB pattern), and the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) the breathing pattern is associated with atrial fibrillation/flutter, CHF, or a neurologic disorder; and (4) the disorder is not better explained by another current sleep disorder, medication use (eg, opioids), or SUD.⁸

Treatment of HF-induced CSA begins with guideline-based medical management with the goal of reducing pulmonary capillary wedge pressure or increasing left ventricular ejection fraction through means that may include cardiac resynchronization therapy or left ventricular assist devices, when clinically indicated. If medical optimization is not sufficient, the next step is continuous positive airway pressure (CPAP or PAP), followed by adaptive servo-ventilation (ASV) if the apnea-hypopnea index (AHI) remains > 15 events per hour and is clinically indicated.

ASV is a second-line PAP therapy modality that uses proprietary algorithms to provide variable amounts of pressure that alternate between expiratory and inspiratory phases of the respiratory cycle in combination with physician-set or automatic backup respiratory rate designed to stabilize ventilation in patients with CSA and CSB. The inability to adjust tidal volume, potentially resulting in insufficient tidal volumes or ventilation, results in the contraindication for its use in patients with CSA with comorbid conditions that may result in hypercapnic respiratory failure. These conditions include chronic hypoventilation in obesity hypoventilation syndrome (OHS), moderate-to-severe chronic obstructive pulmonary disease, chronic elevation of PaCO₂ on arterial blood gas > 45 mm Hg, and restrictive thoracic or neuromuscular disease.¹²

Although ASV is more effective in normalizing AHI in patients with HF and CSA than is CPAP therapy, the clinical indications for ASV in the setting of HFrEF changed drastically with the publication of the landmark SERVE-HF trial, which investigated the effects of adding ASV to guideline-based medical management on survival and cardiovascular outcomes in patients with HFrEF and predominant CSA.¹³ The study did not show a difference between the ASV and control groups for the primary endpoint: a composite of time to first event of death from any cause, lifesaving cardiovascular intervention (transplantation, implantation of a long-term ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization for worsening HF. However, the study showed a statistically and clinically significant increased risk of all-cause and cardiovascular mortality in the ASV group compared with the control group.¹³ A possible explanation for the increased all-cause and cardiovascular mortality is that CSA potentially serves a protective mechanism that when eliminated results in deleterious clinical outcomes. This resulted in significant changes in the treatment algorithm for HF-induced CSA with left ventricular ejection fraction of at least 45% becoming the cutoff for therapeutic decisions.

Treatment-Emergent CSA

Treatment-emergent CSA (TECSA, also known as complex sleep apnea) has been defined by the ICSD-3 by the following criteria: (1) diagnostic PSG with ≥ 5 events per hour of predominantly obstructive events; (2) resolution of obstructive events with PAP without a backup rate and CSA index (CAI) ≥ 5 per hour with central events ≥ 50% of the AHI; and (3) CSA not better explained by another disorder.⁸ Patients with TECSA can be further classified into those who have transient events that resolve within weeks to months, those with persistent events, and those with delayed events that may develop weeks to months after initiating PAP therapy.¹⁴

PAP treatment can decrease the PaCO₂ below the AT due to removal of flow limitation in previously obstructed upper airways, resulting in TECSA.^15,16 PAP therapy has not been the only treatment where new CSA has been identified on initiation. A 2021 systematic review identified patients who developed new-onset CSA with mandibular advancement device (MAD), hypoglossal nerve stimulator, tongue protrusion device, and nasal expiratory PAP device use, as well as after tracheostomy, maxillofacial surgery, and other surgeries, such as nasal and uvulopalatopharyngoplasty.¹⁷

The prevalence of TECSA has been noted to range between 0.6% and 20.3%, but Nigam and colleagues estimated a prevalence of 8.4% in their systematic review.^11,14 The variability in prevalence between studies could be due to differences in study design (retrospective vs prospective vs cross-sectional), diagnostic and inclusion criteria, patient population, and type of study used (full-night vs split-night vs both).^18,19 Risk factors for TECSA include male sex; older age; lower body mass index; higher baseline AHI, CAI, and arousal index; chronic medical issues such as CHF and coronary artery disease; opioid use; higher CPAP settings; excessive mask leak; and bilevel PAP (BiPAP) use.²⁰ Identifying these risk factors is important, as patients with TECSA are at higher risk of discontinuing therapy and of developing PAP intolerance.^15,20

Most patients with TECSA can continue CPAP therapy with resolution of events over weeks to months, but treatment of comorbid conditions should be optimized as they could be contributing factors. Zeineddine and colleagues recommend continuation of CPAP for 3 months if the patient has minor or no symptoms.¹⁹ A 2018 systematic review noted that 14.3% to 46.2% of TECSA patients will have persistent TECSA and some will develop TECSA after at least 1 month of PAP therapy.¹⁴ For these patients and those with severe symptoms in spite of therapy, a switch to BiPAP spontaneous/timed (BiPAP-S/T) or ASV should be considered, if not contraindicated based on comorbidities.²¹ Medications such as acetazolamide, oxygen therapy, and CO₂ supplementation have also been discussed as alternative treatments, but these options should not be first-line therapies and should be used on a case-by-case basis as adjuncts to PAP therapy.^16,17

Altitude-Induced CSA

Also known as CSA due to high-altitude periodic breathing (CSA-HAPB), this form of CSA occurs in nearly all lowlanders at altitudes above 3000 m, with severity increasing with altitude.¹⁵ The exact altitude at which it occurs varies based on an individual’s physiology. CSA-HAPB occurs in response to the low barometric pressure at altitude, combined with stable fraction of oxygen, resulting in decreased inspired partial pressure of oxygen and hypoxia. The normal physiologic response to hypoxia is increased ventilation, which can cause hypocapnia, suppressing respiratory drive and resulting in CSAs. The instability of the respiratory response results in cyclical CSAs followed by hyperventilation. This periodic breathing then causes arousals from sleep, driving further sleep fragmentation and exacerbation of baseline desaturation and instability in the cyclical respiratory response. There is individual variability in hypoxic chemoresponsiveness (loop gain). Compensatory mechanisms are most robust when an individual routinely dwells at high altitude, resulting in acclimatization, rather than traveling there for a brief stay. Genetics and cardiac output also contribute to the effectiveness of compensation to altitude.

CSA-HAPB is defined by the following ICSD-3 criteria: (1) Recent ascent to a high altitude (typically ≥ 2500 m, although some individuals may exhibit the disorder at altitudes as low as 1500 m); (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia; (3) symptoms are clinically attributable to HAPB, or PSG, if performed, reveals recurrent CSAs or hypopneas primarily during non-REM sleep at a frequency of ≥ 5 events per hour; (4) the disorder is not better explained by another current sleep disorder, medical or neurological disorder, medication use (eg, narcotics), or SUD.⁸

Treatment options to improve nocturnal oxygen saturation and reduce or eliminate CSA-HAPB in nonacclimatized individuals include oxygen-enriched air, acetazolamide, or combination treatment with acetazolamide and automatic PAP (APAP).²² A meta-analysis looking at the effectiveness of acetazolamide in 8 different randomized controlled trials demonstrated that a dose of 250 mg per day was effective in improving sleep apnea at altitude as measured by a decrease in AHI, decrease in percentage of periodic breathing, and increasing oxygenation during sleep.¹⁵ The question of superiority of combined acetazolamide with APAP to placebo with APAP in treatment of high-altitude OSA was addressed in a randomized double-blind, placebo-controlled trial. The results showed that combined APAP (5-15 cm of water pressure) and acetazolamide (250 mg morning, 500 mg evening) decreased the AHI to normal range, whereas central events persisted in the APAP and placebo group.²³ In addition, Latshang and colleagues have demonstrated that ASV may not be as efficacious for controlling CSA-HAPB in nonacclimatized individuals compared with oxygen therapy and suggested that further research is warranted examining if ASV device algorithm adjustment improves efficacy of this therapeutic option.²⁴

Comorbidity-Induced CSA

Several medical conditions may be associated with CSA, including chronic kidney disease (CKD), pulmonary hypertension, acromegaly, and hypothyroidism. The common pathophysiologic link is that these disorders may result in alteration of ventilatory responses to CO₂, ultimately resulting in CSA.

As many as 10% of patients with CKD may experience CSA.^25,26 The complications encountered in CKD include fluid overload with pulmonary edema, chronic metabolic acidosis, and anemia. These can provoke hyperventilation in addition to poor sleep quality, triggering arousals that further drive CSA in these patients. Additional risk factors for CSA in this population include atrial fibrillation and cardiac dysfunction. Clinical interventions that have demonstrated reduction in CSA include hemodialysis at night vs daytime and using bicarbonate buffer vs acetate for hemodialysis ^22-24,26-29

Hypersecretion of growth hormone in acromegaly also results in hyperventilation contributing to CSA. While medical and surgical management of acromegaly results in a reduction in OSA, there is limited evidence on the outcome of the CSA after these interventions.

Hypothyroidism and CSA both present with similar symptoms of fatigue, daytime sleepiness, depression, and headaches. Studies suggest that respiratory muscle fatigue and decreased ventilatory response to hypercapnia and hypoxia contribute to apnea in this population. In one study, 27% of hypothyroid patients had a blunted response to hypercapnia, and 34% suffered from a blunted response to hypoxia. The same study showed universal reversal of the impairment following thyroid replacement therapy and return to euthyroid state.³⁰ Similarly, multiple studies have shown reversal of respiratory muscle fatigue after initiation of thyroid replacement.^30-32 Assessing thyroid function is an appropriate initial step during any sleep-disordered breathing workup, as it is a reversible cause of apnea. Up to 2.4% of patients presenting for PSG (and diagnosed with OSA) are found to have undiagnosed hypothyroidism.^32,33 In a military population, treatment of a secondary cause of CSA, such as hypothyroidism, could remove some administrative burden as well as improve service members’ quality of life.

If CSA persists despite previous treatment strategies, then clinicians should focus on the optimization of treatment for comorbid conditions. If that does not resolve CSA, CPAP should be used when AHI remains above 15 events per hour or ASV can be used.

Idiopathic CSA

There are limited data on the pathophysiology and prevalence of idiopathic CSA. In most cases it is hypocapnic CSA, which occurs after an arousal from sleep causing hyperventilation that causes hypocapnia below the apnea threshold similar to CSA-HAPB. Therapeutic options based on addressing underlying pathophysiology include increasing CO₂ by inhalation or addition of dead space. Additional therapeutic options to reduce the arousals and CSAs include hypnotics, such as zolpidem and acetazolamide, but these should be administered only with close clinical monitoring.If symptoms continue, CPAP or ASV may be trialed; however, limited clinical evidence of efficacy exists.¹⁵

For patients with moderate-to-severe CSA, an additional treatment option includes an implantable device (eg, Zoll remede¯), which stimulates the phrenic nerve to move the diaphragm and restore normal breathing. This device is not indicated for those with OSA. Based on data submitted to the US Food and Drug Administration, AHI is reduced by ≥ 50% in 51% of patients with the implanted device and by 11% in patients without the device. Five-year follow-up data show sustained improvements.³⁴

Hypercapnic CSA

CSA due to a medication or substance requires the following criteria: (1) the patient is taking an opioid or other respiratory depressant; (2) the patient reports sleepiness, awakening with shortness of breath, snoring, witnessed apneas, or insomnia (difficulty initiating or maintaining sleep, frequent awakenings, or nonrestorative sleep); (3) PSG reveals ≥ 5 CSAs and/or central hypopneas per hour of sleep; the number of CSAs and/or central hypopneas is > 50% of the total number of apneas and hypopneas; and there is no evidence of CSB; and (4) the disorder is not better explained by another current sleep disorder.⁸

Drugs that affect the respiratory centers, such as opiates and opioids, γ aminobutyric acid (GABA) type A and B receptor agonists, and P2Y(12) receptor antagonists such as ticagrelor, may result in alterations in ventilatory drive in the central nervous system respiratory centers, resulting in CSA.

Opioids are prescribed either for chronic pain or to treat opiate addiction with methadone, resulting in about one-third of chronic opioid users having some form of CSA.³⁵ CSA may be seen after opioids have been used for at least 2 months. A dose-dependent effect exists with high doses of opioids, typically resulting in hypoventilation, hypercapnia, and hypoxemia with ataxic or erratic breathing and a periodic breathing pattern similar to those described in CSA-HAPB or idiopathic CSA. About 14% to 60% of methadone patients also demonstrate CSA or ataxic breathing.^35,36

Benzodiazepines (GABA-A receptor agonists) and baclofen (a GABA-B receptor agonist) depress central ventilatory drive, blunt the response to hypoxia and hypercapnia, leading to CSAs, and increase risk for OSA by increasing upper airway obstruction through reduction in tone. Use of these medications with antidepressants or opioids further exacerbates this response.

Unlike the other medications previously described, ticagrelor, a first-line dual antiplatelet therapy medication indicated for acute coronary syndrome treatment, actually increases the activity of the respiratory centers but may result in CSA.

First-line treatment, if possible, is reduction in medication dose or complete withdrawal. Additional treatment options include PAP therapies: CPAP, BiPAP, ASV, and oxygen therapy with or without PAP.^37,38 The literature has demonstrated that for the treatment of opioid-associated CSA, ASV (in cases of normocapnia) and noninvasive ventilation (NIV)/BiPAP (in cases with hypercapnia or REM sleep hypoventilation) are superior treatment options when compared with conventional CPAP for elimination of respiratory events. CPAP with oxygen therapy and BiPAP with oxygen therapy are more effective than CPAP alone in reducing respiratory events. However, concerns remain that as with CSA in HF, CSA in chronic opioid users may serve as a physiologic protective mechanism to prevent further clinical injury from opioids. Similarly, as in the use of ASV in the SERVE-HF trial, focusing on elimination of respiratory events may prove detrimental. More studies are needed to determine whether reducing the number of CSA events in chronic opioid users is clinically beneficial when other health outcomes, such as cardiovascular, neurocognitive, hospital/intensive care unit admissions, and mortality risks are examined.

Neuromuscular-Induced CSA

CSA also is highly prevalent in neuromuscular conditions, such as amyotrophic lateral sclerosis, Duchenne muscular dystrophy, myotonic dystrophy, advanced multiple sclerosis, and acid maltase deficiency. There is reduced respiratory muscle strength and tone in these disorders, resulting in alveolar hypoventilation with hypercapnia. Given the hypercapnia, NIV/BiPAP is the first-line treatment to improve survival, gas exchange, symptom burden, and quality of life.

Stroke-Induced CSA

Extensive cerebrovascular events commonly precipitate sleep-related breathing disorders. The incidence increases in the acute phase of stroke and decreases 3 to 6 months poststroke; however, incidence also depends on the severity of the stroke.^7,39,40 Stroke also has been shown to be a predictor of CSA (odds ratio, 1.65; 95% CI, 1.50-1.82; P < .001) in a retrospective analysis of a large cohort of US veterans.² The location of the lesion often determines whether normocapnic or hypercapnic CSA will predominate, based on ventilatory instability resulting in normocapnia or reduced ventilatory drive resulting in hypercapnic CSA. PSG results and blood gases direct the treatment options. CSA with normocapnia is treated with ASV, and patients with hypercapnia/REM sleep hypoventilation are treated with NIV/BiPAP.

Conclusions

While much has been learned about CSA in recent decades, more evidence needs to be gathered to determine optimal treatment strategies and the impact on patient prognosis. The identification of CSA can lead to the diagnosis of previously unrecognized medical conditions. With proper diagnosis and treatment, we can optimize clinical management and improve patients’ prognosis and quality of life.

Acknowledgments

The authors thank the librarians of the Franzello Aeromedical Library in particular Sara Craycraft, Catherine Stahl, Kristen Young and Elizabeth Irvine for their support of this publication.