Literature Review

Use of race-based diabetes screening thresholds could reduce the disparity that arises from current screening guidelines in the United States, new research suggests.

In August 2021, the U.S. Preventive Services Task Force (USPSTF) lowered the recommended age for type 2 diabetes screening from 40 to 35 years among people with a body mass index of 25 kg/m² or greater.

However, the diabetes rate among ethnic minorities aged 35-70 years in the United States is not just higher overall but, in certain populations, also occurs more frequently at a younger age and at lower BMIs, the new study indicates.

Among people with a BMI below 25 kg/m², the diabetes prevalence is two to four times higher among Asian, Black, and Hispanic Americans than among the U.S. White population.

And the authors of the new study, led by Rahul Aggarwal, MD, predict that if screening begins at age 35 years, the BMI cut-off equivalent to 25 kg/m² for White Americans would be 18.5 kg/m2 for Hispanic and Black Americans and 20 kg/m² for Asian Americans.

“While diabetes has often been thought of as a disease that primarily affects adults with overweight or [obesity], our findings suggest that normal-weight adults in minority groups have surprisingly high rates of diabetes,” Dr. Aggarwal, senior resident physician in internal medicine at Harvard Medical School, Boston, told this news organization.

“Assessing diabetes risks in certain racial/ethnic groups will be necessary, even if these adults do not have overweight or [obesity],” he added.

Not screening in this way “is a missed opportunity for early intervention,” he noted.  

And both the authors and an editorialist stress that the issue isn’t just theoretical.

“USPSTF recommendations influence what payers choose to cover, which in turn determines access to preventative services ... Addressing the staggering inequities in diabetes outcomes will require substantial investments in diabetes prevention and treatment, but making screening more equitable is a good place to start,” said senior author Dhruv S. Kazi, MD, of the Smith Center for Outcomes Research in Cardiology and director of the Cardiac Critical Care Unit at Beth Israel, Boston.
 

Screen minorities at a younger age if current BMI threshold kept

In their study, based on data from the National Health and Nutrition Examination Survey (NHANES) for 2011-2018, Dr. Aggarwal and colleagues also calculated that, if the BMI threshold is kept at 25 kg/m², then the equivalent age cut-offs for Asian, Black, and Hispanic Americans would be 23, 21, and 25 years, respectively, compared with 35 years for White Americans.

The findings were published online  in the Annals of Internal Medicine.

The prevalence of diabetes in those aged 35-70 years in the NHANES population was 17.3% for Asian Americans and 12.5% for those who were White (odds ratio, 1.51 vs. Whites). Among Black Americans and Mexican Americans, the prevalence was 20.7% and 20.6%, respectively, almost twice the prevalence in Whites (OR, 1.85 and 1.80). For other Hispanic Americans, the prevalence was 16.4% (OR, 1.37 vs. Whites). All of those differences were significant, compared with White Americans.

Undiagnosed diabetes was also significantly more common among minority populations, at 27.6%, 22.8%, 21.2%, and 23.5% for Asian, Black, Mexican, and other Hispanic Americans, respectively, versus 12.5% for White Americans.
 

‘The time has come for USPSTF to offer more concrete guidance’

“While there is more work to be done on carefully examining the long-term risk–benefit trade-off of various diabetes screening, I believe the time has come for USPSTF to offer more concrete guidance on the use of lower thresholds for screening higher-risk individuals,” Dr. Kazi told this news organization.

The author of an accompanying editorial agrees, noting that in a recent commentary the USPSTF, itself, “acknowledged the persistent inequalities across the screening-to-treatment continuum that result in racial/ethnic health disparities in the United States.”

And the USPSTF “emphasized the need to improve systems of care to ensure equitable and consistent delivery of high-quality preventive and treatment services, with special attention to racial/ethnic groups who may experience worse health outcomes,” continues Quyen Ngo-Metzger, MD, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California.

For other conditions, including cancer, cardiovascular disease, and infectious disease, the USPSTF already recommends risk-based preventive services.

“To address the current inequity in diabetes screening, the USPSTF should apply the same consideration to its diabetes screening recommendation,” she notes.
 

‘Implementation will require an eye for pragmatism’

Asked about how this recommendation might be carried out in the real world, Dr. Aggarwal said in an interview that, because all three minority groups with normal weight had similar diabetes risk profiles to White adults with overweight, “one way for clinicians to easily implement these findings is by screening all Asian, Black, and Hispanic adults ages 35-70 years with normal weight for diabetes, similarly to how all White adults ages 35-70 years with overweight are currently recommended for screening.”

Dr. Kazi said: “I believe that implementation will require an eye for pragmatism,” noting that another option would be to have screening algorithms embedded in the electronic health record to flag individuals who qualify.

In any case, “the simplicity of the current one-size-fits-all approach is alluring, but it is profoundly inequitable. The more I look at the empiric evidence on diabetes burden in our communities, the more the status quo becomes untenable.”

However, Dr. Kazi also noted, “the benefit of any screening program relates to what we do with the information. The key is to ensure that folks identified as having diabetes – or better still prediabetes – receive timely lifestyle and pharmacological interventions to avert its long-term complications.”

This study was supported by institutional funds from the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology. Dr. Aggarwal, Dr. Kazi, and Dr. Ngo-Metzger have reported no relevant relationships.

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

Use of race-based diabetes screening thresholds could reduce the disparity that arises from current screening guidelines in the United States, new research suggests.

In August 2021, the U.S. Preventive Services Task Force (USPSTF) lowered the recommended age for type 2 diabetes screening from 40 to 35 years among people with a body mass index of 25 kg/m² or greater.

However, the diabetes rate among ethnic minorities aged 35-70 years in the United States is not just higher overall but, in certain populations, also occurs more frequently at a younger age and at lower BMIs, the new study indicates.

Among people with a BMI below 25 kg/m², the diabetes prevalence is two to four times higher among Asian, Black, and Hispanic Americans than among the U.S. White population.

And the authors of the new study, led by Rahul Aggarwal, MD, predict that if screening begins at age 35 years, the BMI cut-off equivalent to 25 kg/m² for White Americans would be 18.5 kg/m2 for Hispanic and Black Americans and 20 kg/m² for Asian Americans.

“While diabetes has often been thought of as a disease that primarily affects adults with overweight or [obesity], our findings suggest that normal-weight adults in minority groups have surprisingly high rates of diabetes,” Dr. Aggarwal, senior resident physician in internal medicine at Harvard Medical School, Boston, told this news organization.

“Assessing diabetes risks in certain racial/ethnic groups will be necessary, even if these adults do not have overweight or [obesity],” he added.

Not screening in this way “is a missed opportunity for early intervention,” he noted.  

And both the authors and an editorialist stress that the issue isn’t just theoretical.

“USPSTF recommendations influence what payers choose to cover, which in turn determines access to preventative services ... Addressing the staggering inequities in diabetes outcomes will require substantial investments in diabetes prevention and treatment, but making screening more equitable is a good place to start,” said senior author Dhruv S. Kazi, MD, of the Smith Center for Outcomes Research in Cardiology and director of the Cardiac Critical Care Unit at Beth Israel, Boston.
 

Screen minorities at a younger age if current BMI threshold kept

In their study, based on data from the National Health and Nutrition Examination Survey (NHANES) for 2011-2018, Dr. Aggarwal and colleagues also calculated that, if the BMI threshold is kept at 25 kg/m², then the equivalent age cut-offs for Asian, Black, and Hispanic Americans would be 23, 21, and 25 years, respectively, compared with 35 years for White Americans.

The findings were published online  in the Annals of Internal Medicine.

The prevalence of diabetes in those aged 35-70 years in the NHANES population was 17.3% for Asian Americans and 12.5% for those who were White (odds ratio, 1.51 vs. Whites). Among Black Americans and Mexican Americans, the prevalence was 20.7% and 20.6%, respectively, almost twice the prevalence in Whites (OR, 1.85 and 1.80). For other Hispanic Americans, the prevalence was 16.4% (OR, 1.37 vs. Whites). All of those differences were significant, compared with White Americans.

Undiagnosed diabetes was also significantly more common among minority populations, at 27.6%, 22.8%, 21.2%, and 23.5% for Asian, Black, Mexican, and other Hispanic Americans, respectively, versus 12.5% for White Americans.
 

‘The time has come for USPSTF to offer more concrete guidance’

“While there is more work to be done on carefully examining the long-term risk–benefit trade-off of various diabetes screening, I believe the time has come for USPSTF to offer more concrete guidance on the use of lower thresholds for screening higher-risk individuals,” Dr. Kazi told this news organization.

The author of an accompanying editorial agrees, noting that in a recent commentary the USPSTF, itself, “acknowledged the persistent inequalities across the screening-to-treatment continuum that result in racial/ethnic health disparities in the United States.”

And the USPSTF “emphasized the need to improve systems of care to ensure equitable and consistent delivery of high-quality preventive and treatment services, with special attention to racial/ethnic groups who may experience worse health outcomes,” continues Quyen Ngo-Metzger, MD, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California.

For other conditions, including cancer, cardiovascular disease, and infectious disease, the USPSTF already recommends risk-based preventive services.

“To address the current inequity in diabetes screening, the USPSTF should apply the same consideration to its diabetes screening recommendation,” she notes.
 

‘Implementation will require an eye for pragmatism’

Asked about how this recommendation might be carried out in the real world, Dr. Aggarwal said in an interview that, because all three minority groups with normal weight had similar diabetes risk profiles to White adults with overweight, “one way for clinicians to easily implement these findings is by screening all Asian, Black, and Hispanic adults ages 35-70 years with normal weight for diabetes, similarly to how all White adults ages 35-70 years with overweight are currently recommended for screening.”

Dr. Kazi said: “I believe that implementation will require an eye for pragmatism,” noting that another option would be to have screening algorithms embedded in the electronic health record to flag individuals who qualify.

In any case, “the simplicity of the current one-size-fits-all approach is alluring, but it is profoundly inequitable. The more I look at the empiric evidence on diabetes burden in our communities, the more the status quo becomes untenable.”

However, Dr. Kazi also noted, “the benefit of any screening program relates to what we do with the information. The key is to ensure that folks identified as having diabetes – or better still prediabetes – receive timely lifestyle and pharmacological interventions to avert its long-term complications.”

This study was supported by institutional funds from the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology. Dr. Aggarwal, Dr. Kazi, and Dr. Ngo-Metzger have reported no relevant relationships.

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

Use of race-based diabetes screening thresholds could reduce the disparity that arises from current screening guidelines in the United States, new research suggests.

In August 2021, the U.S. Preventive Services Task Force (USPSTF) lowered the recommended age for type 2 diabetes screening from 40 to 35 years among people with a body mass index of 25 kg/m² or greater.

However, the diabetes rate among ethnic minorities aged 35-70 years in the United States is not just higher overall but, in certain populations, also occurs more frequently at a younger age and at lower BMIs, the new study indicates.

Among people with a BMI below 25 kg/m², the diabetes prevalence is two to four times higher among Asian, Black, and Hispanic Americans than among the U.S. White population.

And the authors of the new study, led by Rahul Aggarwal, MD, predict that if screening begins at age 35 years, the BMI cut-off equivalent to 25 kg/m² for White Americans would be 18.5 kg/m2 for Hispanic and Black Americans and 20 kg/m² for Asian Americans.

“While diabetes has often been thought of as a disease that primarily affects adults with overweight or [obesity], our findings suggest that normal-weight adults in minority groups have surprisingly high rates of diabetes,” Dr. Aggarwal, senior resident physician in internal medicine at Harvard Medical School, Boston, told this news organization.

“Assessing diabetes risks in certain racial/ethnic groups will be necessary, even if these adults do not have overweight or [obesity],” he added.

Not screening in this way “is a missed opportunity for early intervention,” he noted.  

And both the authors and an editorialist stress that the issue isn’t just theoretical.

“USPSTF recommendations influence what payers choose to cover, which in turn determines access to preventative services ... Addressing the staggering inequities in diabetes outcomes will require substantial investments in diabetes prevention and treatment, but making screening more equitable is a good place to start,” said senior author Dhruv S. Kazi, MD, of the Smith Center for Outcomes Research in Cardiology and director of the Cardiac Critical Care Unit at Beth Israel, Boston.
 

Screen minorities at a younger age if current BMI threshold kept

In their study, based on data from the National Health and Nutrition Examination Survey (NHANES) for 2011-2018, Dr. Aggarwal and colleagues also calculated that, if the BMI threshold is kept at 25 kg/m², then the equivalent age cut-offs for Asian, Black, and Hispanic Americans would be 23, 21, and 25 years, respectively, compared with 35 years for White Americans.

The findings were published online  in the Annals of Internal Medicine.

The prevalence of diabetes in those aged 35-70 years in the NHANES population was 17.3% for Asian Americans and 12.5% for those who were White (odds ratio, 1.51 vs. Whites). Among Black Americans and Mexican Americans, the prevalence was 20.7% and 20.6%, respectively, almost twice the prevalence in Whites (OR, 1.85 and 1.80). For other Hispanic Americans, the prevalence was 16.4% (OR, 1.37 vs. Whites). All of those differences were significant, compared with White Americans.

Undiagnosed diabetes was also significantly more common among minority populations, at 27.6%, 22.8%, 21.2%, and 23.5% for Asian, Black, Mexican, and other Hispanic Americans, respectively, versus 12.5% for White Americans.
 

‘The time has come for USPSTF to offer more concrete guidance’

“While there is more work to be done on carefully examining the long-term risk–benefit trade-off of various diabetes screening, I believe the time has come for USPSTF to offer more concrete guidance on the use of lower thresholds for screening higher-risk individuals,” Dr. Kazi told this news organization.

The author of an accompanying editorial agrees, noting that in a recent commentary the USPSTF, itself, “acknowledged the persistent inequalities across the screening-to-treatment continuum that result in racial/ethnic health disparities in the United States.”

And the USPSTF “emphasized the need to improve systems of care to ensure equitable and consistent delivery of high-quality preventive and treatment services, with special attention to racial/ethnic groups who may experience worse health outcomes,” continues Quyen Ngo-Metzger, MD, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California.

For other conditions, including cancer, cardiovascular disease, and infectious disease, the USPSTF already recommends risk-based preventive services.

“To address the current inequity in diabetes screening, the USPSTF should apply the same consideration to its diabetes screening recommendation,” she notes.
 

‘Implementation will require an eye for pragmatism’

Asked about how this recommendation might be carried out in the real world, Dr. Aggarwal said in an interview that, because all three minority groups with normal weight had similar diabetes risk profiles to White adults with overweight, “one way for clinicians to easily implement these findings is by screening all Asian, Black, and Hispanic adults ages 35-70 years with normal weight for diabetes, similarly to how all White adults ages 35-70 years with overweight are currently recommended for screening.”

Dr. Kazi said: “I believe that implementation will require an eye for pragmatism,” noting that another option would be to have screening algorithms embedded in the electronic health record to flag individuals who qualify.

In any case, “the simplicity of the current one-size-fits-all approach is alluring, but it is profoundly inequitable. The more I look at the empiric evidence on diabetes burden in our communities, the more the status quo becomes untenable.”

However, Dr. Kazi also noted, “the benefit of any screening program relates to what we do with the information. The key is to ensure that folks identified as having diabetes – or better still prediabetes – receive timely lifestyle and pharmacological interventions to avert its long-term complications.”

This study was supported by institutional funds from the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology. Dr. Aggarwal, Dr. Kazi, and Dr. Ngo-Metzger have reported no relevant relationships.

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

Long-term use of a proton-pump inhibitor (PPI) was associated with an increased risk of being diagnosed with type 2 diabetes in a large, population-based case-control study in Italy.

The risk of diabetes increased from 19% to 56% as treatment duration increased from 8 weeks to more than 2 years, and prolonged treatment was associated with an even higher risk of diabetes in the youngest patients (age 40-65) and those with the most comorbidities.

The results suggest that “physicians should therefore avoid unnecessary prescription of this class of drugs, particularly for long-term use,” say Stefano Ciardullo, MD, University of Milano-Bicocca, Italy, and colleagues, in their article recently published online in the Journal of Clinical Endocrinology & Metabolism.

“Nonetheless, epidemiologic evidence on the topic remains conflicting,” they acknowledge, adding that “future studies are still needed to validate our findings.”

If the results are confirmed, these “may have important implications for both public health and clinical practice, given the high number of patients being treated with PPIs and the influence of diabetes on morbidity and mortality related to its possible micro- and macrovascular complications,” Dr. Ciardullo and colleagues conclude.
 

Not enough data to support a change in practice

The current findings align with a recent analysis of three prospective cohort studies of U.S. health care workers that showed a progressively increased risk of diabetes with longer treatment with PPIs, David A. Leiman, MD, MSHP, who was not involved with the current study, told this news organization in an email. “But the effect size remains relatively small and may be explained by residual or unmeasured confounding,” he cautioned.

“Ultimately, there do not seem to be enough data to support a change in clinical practice from this study alone, and, as a result, clinicians should continue to inform patients of the best available evidence regarding the benefits and risks of PPIs,” said Dr. Leiman, assistant professor of medicine, Division of Gastroenterology, Duke University Medical Center, Durham, N.C.

“Recent best practice advice from the American Gastroenterological Association does not recommend screening for insulin resistance among PPI users [and recommends that the decision to discontinue PPIs] should be based solely on the lack of an indication for PPI use, and not because of concern for PPI-associated adverse events,” he noted.

“Clinicians should be prepared to discuss the described risks associated with PPIs,” said Dr. Leiman, but they should “also feel comfortable affirming their safety profile and substantial efficacy in managing symptoms and preventing complications when prescribed for the appropriate indication.”

First-choice therapy for acid-related disorders

PPIs have become first-choice therapy for patients with acid-related disorders such as gastroesophageal reflux disease, Barrett esophagus, and peptic ulcer, and to prevent gastrointestinal bleeding while on nonsteroidal anti-inflammatory drugs (NSAIDs), Dr. Ciardullo and colleagues explain.

However, several studies have identified potential fractures, hypomagnesemia, gastric carcinoids, chronic kidney disease, dementia, and Clostridium difficile diarrhea with prolonged use of PPIs, and these agents can cause changes in the gut microbiome that may play a role in diabetes and other metabolic diseases.

To investigate a potential association between PPIs and type 2 diabetes, the researchers analyzed data from 777,420 patients age 40 and older who were newly treated with PPIs between 2010 and 2015 in Lombardy, Italy.

Of these, 50,540 patients were diagnosed with type 2 diabetes during follow-up until 2020 (a mean follow-up of 6.2 years and a diabetes incidence of 10.6 cases per 1,000 person-years).

The researchers matched 50,535 patients diagnosed with diabetes during follow-up with 50,535 control patients who had the same age, sex, and clinical status.

Patients were a mean age of 66 years and half were men. The most prescribed PPIs were pantoprazole and omeprazole, and the patients diagnosed with diabetes were more likely to use antihypertensives and lipid-lowering drugs.

Compared with patients who received PPIs for less than 8 weeks, those who received PPIs for 8 weeks to 6 months had a 19% increased risk of being diagnosed with diabetes during follow-up (odds ratio, 1.19; 95% confidence interval, 1.15-1.24), after adjusting for age, clinical profile, comorbidities, medical therapy, and PPI type.

Patients who received PPIs for 6 months to 2 years had a 43% increased risk of the outcome (OR, 1.43; 95% CI, 1.38-1.49), and those who received PPIs for more than 2 years had a 56% increased risk of the outcome (OR, 1.56; 95% CI, 1.49-1.64).

The researchers acknowledge limitations including that the study was not a randomized controlled trial, and it lacked information about over-the-counter medications and unmeasured confounders such as body mass index or family history of diabetes that may have affected the outcomes.

Dr. Leiman added that patients may have had prediabetes or undiagnosed diabetes and symptoms such as heartburn or dyspepsia arising from complications of insulin resistance, for which PPIs might have been prescribed.

The study was funded by a grant from the Italian Ministry of Education, University and Research. Dr. Ciardullo and Dr. Leiman have reported no relevant financial relationships.

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

Long-term use of a proton-pump inhibitor (PPI) was associated with an increased risk of being diagnosed with type 2 diabetes in a large, population-based case-control study in Italy.

The risk of diabetes increased from 19% to 56% as treatment duration increased from 8 weeks to more than 2 years, and prolonged treatment was associated with an even higher risk of diabetes in the youngest patients (age 40-65) and those with the most comorbidities.

The results suggest that “physicians should therefore avoid unnecessary prescription of this class of drugs, particularly for long-term use,” say Stefano Ciardullo, MD, University of Milano-Bicocca, Italy, and colleagues, in their article recently published online in the Journal of Clinical Endocrinology & Metabolism.

“Nonetheless, epidemiologic evidence on the topic remains conflicting,” they acknowledge, adding that “future studies are still needed to validate our findings.”

If the results are confirmed, these “may have important implications for both public health and clinical practice, given the high number of patients being treated with PPIs and the influence of diabetes on morbidity and mortality related to its possible micro- and macrovascular complications,” Dr. Ciardullo and colleagues conclude.
 

Not enough data to support a change in practice

The current findings align with a recent analysis of three prospective cohort studies of U.S. health care workers that showed a progressively increased risk of diabetes with longer treatment with PPIs, David A. Leiman, MD, MSHP, who was not involved with the current study, told this news organization in an email. “But the effect size remains relatively small and may be explained by residual or unmeasured confounding,” he cautioned.

“Ultimately, there do not seem to be enough data to support a change in clinical practice from this study alone, and, as a result, clinicians should continue to inform patients of the best available evidence regarding the benefits and risks of PPIs,” said Dr. Leiman, assistant professor of medicine, Division of Gastroenterology, Duke University Medical Center, Durham, N.C.

“Recent best practice advice from the American Gastroenterological Association does not recommend screening for insulin resistance among PPI users [and recommends that the decision to discontinue PPIs] should be based solely on the lack of an indication for PPI use, and not because of concern for PPI-associated adverse events,” he noted.

“Clinicians should be prepared to discuss the described risks associated with PPIs,” said Dr. Leiman, but they should “also feel comfortable affirming their safety profile and substantial efficacy in managing symptoms and preventing complications when prescribed for the appropriate indication.”

First-choice therapy for acid-related disorders

PPIs have become first-choice therapy for patients with acid-related disorders such as gastroesophageal reflux disease, Barrett esophagus, and peptic ulcer, and to prevent gastrointestinal bleeding while on nonsteroidal anti-inflammatory drugs (NSAIDs), Dr. Ciardullo and colleagues explain.

However, several studies have identified potential fractures, hypomagnesemia, gastric carcinoids, chronic kidney disease, dementia, and Clostridium difficile diarrhea with prolonged use of PPIs, and these agents can cause changes in the gut microbiome that may play a role in diabetes and other metabolic diseases.

To investigate a potential association between PPIs and type 2 diabetes, the researchers analyzed data from 777,420 patients age 40 and older who were newly treated with PPIs between 2010 and 2015 in Lombardy, Italy.

Of these, 50,540 patients were diagnosed with type 2 diabetes during follow-up until 2020 (a mean follow-up of 6.2 years and a diabetes incidence of 10.6 cases per 1,000 person-years).

The researchers matched 50,535 patients diagnosed with diabetes during follow-up with 50,535 control patients who had the same age, sex, and clinical status.

Patients were a mean age of 66 years and half were men. The most prescribed PPIs were pantoprazole and omeprazole, and the patients diagnosed with diabetes were more likely to use antihypertensives and lipid-lowering drugs.

Compared with patients who received PPIs for less than 8 weeks, those who received PPIs for 8 weeks to 6 months had a 19% increased risk of being diagnosed with diabetes during follow-up (odds ratio, 1.19; 95% confidence interval, 1.15-1.24), after adjusting for age, clinical profile, comorbidities, medical therapy, and PPI type.

Patients who received PPIs for 6 months to 2 years had a 43% increased risk of the outcome (OR, 1.43; 95% CI, 1.38-1.49), and those who received PPIs for more than 2 years had a 56% increased risk of the outcome (OR, 1.56; 95% CI, 1.49-1.64).

The researchers acknowledge limitations including that the study was not a randomized controlled trial, and it lacked information about over-the-counter medications and unmeasured confounders such as body mass index or family history of diabetes that may have affected the outcomes.

Dr. Leiman added that patients may have had prediabetes or undiagnosed diabetes and symptoms such as heartburn or dyspepsia arising from complications of insulin resistance, for which PPIs might have been prescribed.

The study was funded by a grant from the Italian Ministry of Education, University and Research. Dr. Ciardullo and Dr. Leiman have reported no relevant financial relationships.

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

Long-term use of a proton-pump inhibitor (PPI) was associated with an increased risk of being diagnosed with type 2 diabetes in a large, population-based case-control study in Italy.

The risk of diabetes increased from 19% to 56% as treatment duration increased from 8 weeks to more than 2 years, and prolonged treatment was associated with an even higher risk of diabetes in the youngest patients (age 40-65) and those with the most comorbidities.

The results suggest that “physicians should therefore avoid unnecessary prescription of this class of drugs, particularly for long-term use,” say Stefano Ciardullo, MD, University of Milano-Bicocca, Italy, and colleagues, in their article recently published online in the Journal of Clinical Endocrinology & Metabolism.

“Nonetheless, epidemiologic evidence on the topic remains conflicting,” they acknowledge, adding that “future studies are still needed to validate our findings.”

If the results are confirmed, these “may have important implications for both public health and clinical practice, given the high number of patients being treated with PPIs and the influence of diabetes on morbidity and mortality related to its possible micro- and macrovascular complications,” Dr. Ciardullo and colleagues conclude.
 

Not enough data to support a change in practice

The current findings align with a recent analysis of three prospective cohort studies of U.S. health care workers that showed a progressively increased risk of diabetes with longer treatment with PPIs, David A. Leiman, MD, MSHP, who was not involved with the current study, told this news organization in an email. “But the effect size remains relatively small and may be explained by residual or unmeasured confounding,” he cautioned.

“Ultimately, there do not seem to be enough data to support a change in clinical practice from this study alone, and, as a result, clinicians should continue to inform patients of the best available evidence regarding the benefits and risks of PPIs,” said Dr. Leiman, assistant professor of medicine, Division of Gastroenterology, Duke University Medical Center, Durham, N.C.

“Recent best practice advice from the American Gastroenterological Association does not recommend screening for insulin resistance among PPI users [and recommends that the decision to discontinue PPIs] should be based solely on the lack of an indication for PPI use, and not because of concern for PPI-associated adverse events,” he noted.

“Clinicians should be prepared to discuss the described risks associated with PPIs,” said Dr. Leiman, but they should “also feel comfortable affirming their safety profile and substantial efficacy in managing symptoms and preventing complications when prescribed for the appropriate indication.”

First-choice therapy for acid-related disorders

PPIs have become first-choice therapy for patients with acid-related disorders such as gastroesophageal reflux disease, Barrett esophagus, and peptic ulcer, and to prevent gastrointestinal bleeding while on nonsteroidal anti-inflammatory drugs (NSAIDs), Dr. Ciardullo and colleagues explain.

However, several studies have identified potential fractures, hypomagnesemia, gastric carcinoids, chronic kidney disease, dementia, and Clostridium difficile diarrhea with prolonged use of PPIs, and these agents can cause changes in the gut microbiome that may play a role in diabetes and other metabolic diseases.

To investigate a potential association between PPIs and type 2 diabetes, the researchers analyzed data from 777,420 patients age 40 and older who were newly treated with PPIs between 2010 and 2015 in Lombardy, Italy.

Of these, 50,540 patients were diagnosed with type 2 diabetes during follow-up until 2020 (a mean follow-up of 6.2 years and a diabetes incidence of 10.6 cases per 1,000 person-years).

The researchers matched 50,535 patients diagnosed with diabetes during follow-up with 50,535 control patients who had the same age, sex, and clinical status.

Patients were a mean age of 66 years and half were men. The most prescribed PPIs were pantoprazole and omeprazole, and the patients diagnosed with diabetes were more likely to use antihypertensives and lipid-lowering drugs.

Compared with patients who received PPIs for less than 8 weeks, those who received PPIs for 8 weeks to 6 months had a 19% increased risk of being diagnosed with diabetes during follow-up (odds ratio, 1.19; 95% confidence interval, 1.15-1.24), after adjusting for age, clinical profile, comorbidities, medical therapy, and PPI type.

Patients who received PPIs for 6 months to 2 years had a 43% increased risk of the outcome (OR, 1.43; 95% CI, 1.38-1.49), and those who received PPIs for more than 2 years had a 56% increased risk of the outcome (OR, 1.56; 95% CI, 1.49-1.64).

The researchers acknowledge limitations including that the study was not a randomized controlled trial, and it lacked information about over-the-counter medications and unmeasured confounders such as body mass index or family history of diabetes that may have affected the outcomes.

Dr. Leiman added that patients may have had prediabetes or undiagnosed diabetes and symptoms such as heartburn or dyspepsia arising from complications of insulin resistance, for which PPIs might have been prescribed.

The study was funded by a grant from the Italian Ministry of Education, University and Research. Dr. Ciardullo and Dr. Leiman have reported no relevant financial relationships.

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

Higher levels of specific carotenoid antioxidants in blood may help guard against age-related dementia, new research suggests.

Investigators found that individuals with the highest serum levels of lutein + zeaxanthin and beta-cryptoxanthin at baseline were less likely to have dementia decades later than were their peers with lower levels of these antioxidants.

Lutein and zeaxanthin are found in green leafy vegetables such as kale, spinach, broccoli, and peas. Beta-cryptoxanthin is found in fruits such as oranges, papaya, tangerines, and persimmons.

“Antioxidants may help protect the brain from oxidative stress, which can cause cell damage,” first author May A. Beydoun, PhD, with the National Institute on Aging (NIA), said in a news release. 

“This is the first nationally representative study to analyze blood levels of antioxidants in relation to dementia risk,” NIA scientific director Luigi Ferrucci, MD, said in an interview.

“Blood test results may be more representative of the actual antioxidant level than a person’s report of what kind of foods they regularly consume,” Dr. Ferrucci added.

The study was published online in Neurology.
 

Reduced dementia risk

The researchers tested associations and interactions of serum vitamins A, C and E, and total and individual serum carotenoids and interactions with incident Alzheimer’s disease (AD) and all-cause dementia.

They analyzed data from 7,283 participants in the Third National Health and Nutrition Examination Survey (NHANES III) who were at least 45 years old at baseline and followed for an average of 16-17 years.

They found serum levels of lutein + zeaxanthin were associated with reduced risk of all-cause dementia among people aged 65 and older in models adjusted for lifestyle.

For lutein + zeaxanthin, every standard deviation (SD) increase (roughly 15.4 µmol/liter) was associated with a 7% decrease in risk for dementia (hazard ratio [HR] 0.93; 95% confidence interval [CI], 0.87-0.99, P = .037). This association was attenuated somewhat after adjustment for socioeconomic status.

Serum levels of beta-cryptoxanthin showed a “strong” inverse relationship with all-cause dementia in age- and sex-adjusted models.

For beta-cryptoxanthin, every SD increase (roughly 8.6 µmol/liter) was associated with a 14% reduced risk for dementia in people aged 45 and older (HR, 0.86; 95% CI, 0.80-0.93, P < .001) and 65 and older (HR, 0.86; 95% CI, 0.80-0.93, P = .001).

This relationship remained strong in models adjusted for sociodemographic and socioeconomic factors but attenuated in subsequent models.

No associations were found for lycopene, alpha-carotene, beta-carotene, or vitamins A, C, or E in the fully adjusted models.

Antagonistic interactions were observed for vitamin A and alpha-carotene, vitamin A and beta-carotene, vitamin E and lycopene, and lycopene and beta-carotene, suggesting putative protective effects of one antioxidant at lower levels of the other, the researchers noted.

“This analysis of an observational study found that the most important carotenoids in potentially protecting the brain may be lutein + zeaxanthin and beta-cryptoxanthin. However, randomized controlled trials are needed to prove causality,” said Dr. Ferrucci.

“Experts do not yet know the daily level of antioxidant intake to promote healthy aging of the brain. More research is needed to establish the necessary level of antioxidant intake – through the diet and/or supplements – to promote brain health and healthy aging,” he added.
 

An important step forward

In an accompanying editorial, Babak Hooshmand, MD, PhD, and Miia Kivipelto, MD, PhD, with Karolinska Institute, Stockholm, noted that while nutrition and dietary components are “potential targets” for dementia risk reduction, observational studies to date have reported “inconsistent findings.”

This study is “an important step towards exploring the complex relationship between antioxidants and dementia because it accounts for factors that could possibly influence the associations and considers interactions between different components,” they wrote.

The findings are “challenging,” they added, because they may lead to the hypothesis that inhibition of oxidative damage by antioxidants might have beneficial effects on preventing dementia.

However, clinical trials of antioxidant supplementation have been mainly “disappointing” and a recent Cochrane review found a lack of evidence for supplement use to preserve cognitive function or prevent dementia, Dr. Hooshmand and Dr. Kivipelto noted.

They added that the study contributes to the belief that antioxidants don’t act independently of each other or other factors, including socioeconomic status and lifestyle, in the mediation of dementia risk.

“A careful examination of the evidence is required to learn how antioxidants influence the complex pathology of dementia, because it appears to be more to it than meets the eye,”they concluded.

The research was supported in part by the Intramural Research Program of the National Institutes of Health and the National Institute on Aging. Dr. Beydoun, Dr. Ferrucci, and Dr. Hooshmand report no relevant disclosures. Dr. Kivipelto has supported advisory boards for Combinostics, Roche, and Biogen.

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

Higher levels of specific carotenoid antioxidants in blood may help guard against age-related dementia, new research suggests.

Investigators found that individuals with the highest serum levels of lutein + zeaxanthin and beta-cryptoxanthin at baseline were less likely to have dementia decades later than were their peers with lower levels of these antioxidants.

Lutein and zeaxanthin are found in green leafy vegetables such as kale, spinach, broccoli, and peas. Beta-cryptoxanthin is found in fruits such as oranges, papaya, tangerines, and persimmons.

“Antioxidants may help protect the brain from oxidative stress, which can cause cell damage,” first author May A. Beydoun, PhD, with the National Institute on Aging (NIA), said in a news release. 

“This is the first nationally representative study to analyze blood levels of antioxidants in relation to dementia risk,” NIA scientific director Luigi Ferrucci, MD, said in an interview.

“Blood test results may be more representative of the actual antioxidant level than a person’s report of what kind of foods they regularly consume,” Dr. Ferrucci added.

The study was published online in Neurology.
 

Reduced dementia risk

The researchers tested associations and interactions of serum vitamins A, C and E, and total and individual serum carotenoids and interactions with incident Alzheimer’s disease (AD) and all-cause dementia.

They analyzed data from 7,283 participants in the Third National Health and Nutrition Examination Survey (NHANES III) who were at least 45 years old at baseline and followed for an average of 16-17 years.

They found serum levels of lutein + zeaxanthin were associated with reduced risk of all-cause dementia among people aged 65 and older in models adjusted for lifestyle.

For lutein + zeaxanthin, every standard deviation (SD) increase (roughly 15.4 µmol/liter) was associated with a 7% decrease in risk for dementia (hazard ratio [HR] 0.93; 95% confidence interval [CI], 0.87-0.99, P = .037). This association was attenuated somewhat after adjustment for socioeconomic status.

Serum levels of beta-cryptoxanthin showed a “strong” inverse relationship with all-cause dementia in age- and sex-adjusted models.

For beta-cryptoxanthin, every SD increase (roughly 8.6 µmol/liter) was associated with a 14% reduced risk for dementia in people aged 45 and older (HR, 0.86; 95% CI, 0.80-0.93, P < .001) and 65 and older (HR, 0.86; 95% CI, 0.80-0.93, P = .001).

This relationship remained strong in models adjusted for sociodemographic and socioeconomic factors but attenuated in subsequent models.

No associations were found for lycopene, alpha-carotene, beta-carotene, or vitamins A, C, or E in the fully adjusted models.

Antagonistic interactions were observed for vitamin A and alpha-carotene, vitamin A and beta-carotene, vitamin E and lycopene, and lycopene and beta-carotene, suggesting putative protective effects of one antioxidant at lower levels of the other, the researchers noted.

“This analysis of an observational study found that the most important carotenoids in potentially protecting the brain may be lutein + zeaxanthin and beta-cryptoxanthin. However, randomized controlled trials are needed to prove causality,” said Dr. Ferrucci.

“Experts do not yet know the daily level of antioxidant intake to promote healthy aging of the brain. More research is needed to establish the necessary level of antioxidant intake – through the diet and/or supplements – to promote brain health and healthy aging,” he added.
 

An important step forward

In an accompanying editorial, Babak Hooshmand, MD, PhD, and Miia Kivipelto, MD, PhD, with Karolinska Institute, Stockholm, noted that while nutrition and dietary components are “potential targets” for dementia risk reduction, observational studies to date have reported “inconsistent findings.”

This study is “an important step towards exploring the complex relationship between antioxidants and dementia because it accounts for factors that could possibly influence the associations and considers interactions between different components,” they wrote.

The findings are “challenging,” they added, because they may lead to the hypothesis that inhibition of oxidative damage by antioxidants might have beneficial effects on preventing dementia.

However, clinical trials of antioxidant supplementation have been mainly “disappointing” and a recent Cochrane review found a lack of evidence for supplement use to preserve cognitive function or prevent dementia, Dr. Hooshmand and Dr. Kivipelto noted.

They added that the study contributes to the belief that antioxidants don’t act independently of each other or other factors, including socioeconomic status and lifestyle, in the mediation of dementia risk.

“A careful examination of the evidence is required to learn how antioxidants influence the complex pathology of dementia, because it appears to be more to it than meets the eye,”they concluded.

The research was supported in part by the Intramural Research Program of the National Institutes of Health and the National Institute on Aging. Dr. Beydoun, Dr. Ferrucci, and Dr. Hooshmand report no relevant disclosures. Dr. Kivipelto has supported advisory boards for Combinostics, Roche, and Biogen.

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

Higher levels of specific carotenoid antioxidants in blood may help guard against age-related dementia, new research suggests.

Investigators found that individuals with the highest serum levels of lutein + zeaxanthin and beta-cryptoxanthin at baseline were less likely to have dementia decades later than were their peers with lower levels of these antioxidants.

Lutein and zeaxanthin are found in green leafy vegetables such as kale, spinach, broccoli, and peas. Beta-cryptoxanthin is found in fruits such as oranges, papaya, tangerines, and persimmons.

“Antioxidants may help protect the brain from oxidative stress, which can cause cell damage,” first author May A. Beydoun, PhD, with the National Institute on Aging (NIA), said in a news release. 

“This is the first nationally representative study to analyze blood levels of antioxidants in relation to dementia risk,” NIA scientific director Luigi Ferrucci, MD, said in an interview.

“Blood test results may be more representative of the actual antioxidant level than a person’s report of what kind of foods they regularly consume,” Dr. Ferrucci added.

The study was published online in Neurology.
 

Reduced dementia risk

The researchers tested associations and interactions of serum vitamins A, C and E, and total and individual serum carotenoids and interactions with incident Alzheimer’s disease (AD) and all-cause dementia.

They analyzed data from 7,283 participants in the Third National Health and Nutrition Examination Survey (NHANES III) who were at least 45 years old at baseline and followed for an average of 16-17 years.

They found serum levels of lutein + zeaxanthin were associated with reduced risk of all-cause dementia among people aged 65 and older in models adjusted for lifestyle.

For lutein + zeaxanthin, every standard deviation (SD) increase (roughly 15.4 µmol/liter) was associated with a 7% decrease in risk for dementia (hazard ratio [HR] 0.93; 95% confidence interval [CI], 0.87-0.99, P = .037). This association was attenuated somewhat after adjustment for socioeconomic status.

Serum levels of beta-cryptoxanthin showed a “strong” inverse relationship with all-cause dementia in age- and sex-adjusted models.

For beta-cryptoxanthin, every SD increase (roughly 8.6 µmol/liter) was associated with a 14% reduced risk for dementia in people aged 45 and older (HR, 0.86; 95% CI, 0.80-0.93, P < .001) and 65 and older (HR, 0.86; 95% CI, 0.80-0.93, P = .001).

This relationship remained strong in models adjusted for sociodemographic and socioeconomic factors but attenuated in subsequent models.

No associations were found for lycopene, alpha-carotene, beta-carotene, or vitamins A, C, or E in the fully adjusted models.

Antagonistic interactions were observed for vitamin A and alpha-carotene, vitamin A and beta-carotene, vitamin E and lycopene, and lycopene and beta-carotene, suggesting putative protective effects of one antioxidant at lower levels of the other, the researchers noted.

“This analysis of an observational study found that the most important carotenoids in potentially protecting the brain may be lutein + zeaxanthin and beta-cryptoxanthin. However, randomized controlled trials are needed to prove causality,” said Dr. Ferrucci.

“Experts do not yet know the daily level of antioxidant intake to promote healthy aging of the brain. More research is needed to establish the necessary level of antioxidant intake – through the diet and/or supplements – to promote brain health and healthy aging,” he added.
 

An important step forward

In an accompanying editorial, Babak Hooshmand, MD, PhD, and Miia Kivipelto, MD, PhD, with Karolinska Institute, Stockholm, noted that while nutrition and dietary components are “potential targets” for dementia risk reduction, observational studies to date have reported “inconsistent findings.”

This study is “an important step towards exploring the complex relationship between antioxidants and dementia because it accounts for factors that could possibly influence the associations and considers interactions between different components,” they wrote.

The findings are “challenging,” they added, because they may lead to the hypothesis that inhibition of oxidative damage by antioxidants might have beneficial effects on preventing dementia.

However, clinical trials of antioxidant supplementation have been mainly “disappointing” and a recent Cochrane review found a lack of evidence for supplement use to preserve cognitive function or prevent dementia, Dr. Hooshmand and Dr. Kivipelto noted.

They added that the study contributes to the belief that antioxidants don’t act independently of each other or other factors, including socioeconomic status and lifestyle, in the mediation of dementia risk.

“A careful examination of the evidence is required to learn how antioxidants influence the complex pathology of dementia, because it appears to be more to it than meets the eye,”they concluded.

The research was supported in part by the Intramural Research Program of the National Institutes of Health and the National Institute on Aging. Dr. Beydoun, Dr. Ferrucci, and Dr. Hooshmand report no relevant disclosures. Dr. Kivipelto has supported advisory boards for Combinostics, Roche, and Biogen.

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

New surveillance data from the Vaccine Adverse Event Reporting System (VAERS) confirm a small but statistically significant increased risk for Guillain-Barré syndrome (GBS) in the 3 weeks after receipt of the Janssen/Johnson & Johnson COVID-19 vaccine.

The Janssen vaccine (Ad26.COV2.S) is a replication-incompetent adenoviral vector vaccine.

The data show no increased risk of GBS with the Pfizer (BNT162b2) or Moderna (mRNA-1273) shots – both mRNA vaccines.

“Our findings support the current guidance from U.S. health officials that preferentially recommend use of mRNA COVID-19 vaccines for primary and booster doses,” Nicola Klein, MD, PhD, with Kaiser Permanente Vaccine Study Center, Oakland, Calif., told this news organization.

“Individuals who choose to receive Janssen/J&J COVID-19 vaccine should be informed of the potential safety risks, including GBS,” Dr. Klein said.

The study was published online in JAMA Network Open.
 

Eleven cases

Between mid-December 2020 and mid-November 2021, roughly 15.1 million doses of COVID-19 vaccine were administered to nearly 7.9 million adults in the United States.

This includes roughly 483,000 doses of the Janssen vaccine, 8.8 million doses of the Pfizer vaccine, and 5.8 million doses of the Moderna vaccine.

The researchers confirmed 11 cases of GBS after the Janssen vaccine.

The unadjusted incidence of GBS (per 100,000 person-years) was 32.4 in the first 21 days after the Janssen vaccine – substantially higher than the expected background rate of 1 to 2 cases per 100,000 person-years.

There were 36 confirmed cases of GBS after mRNA vaccines. The unadjusted incidence in the first 21 days after mRNA vaccination was 1.3 per 100,000 person-years, similar to the overall expected background rate.

In an adjusted head-to-head comparison, GBS incidence during the 21 days after receipt of the Janssen vaccine was 20.6 times higher than the GBS incidence during the 21 days after the Pfizer or Moderna mRNA vaccines, amounting to 15.5 excess cases per million Janssen vaccine recipients.

Most cases of GBS after the Janssen vaccine occurred during the 1- to 21-day risk interval, with the period of greatest risk in the 1-14 days after vaccination.

The findings of this analysis of surveillance data of COVID-19 vaccines are “consistent with an elevated risk of GBS after primary Ad26.COV2.S vaccination,” the authors wrote.
 

Novel presentation?

The researchers note that nearly all individuals who developed GBS after the Janssen vaccine had facial weakness or paralysis, in addition to weakness and decreased reflexes in the limbs, suggesting that the presentation of GBS after COVID-19 adenoviral vector vaccine may be novel.

“More research is needed to determine if the presentation of GBS after adenoviral vector vaccine differs from GBS after other exposures such as Campylobacter jejuni, and to investigate the mechanism for how adenoviral vector vaccines may cause GBS,” Dr. Klein and colleagues said.

“The Vaccine Safety Datalink continues to conduct safety surveillance for all COVID-19 vaccines, including monitoring for GBS and other serious health outcomes after vaccination,” Dr. Klein said in an interview.

This study was supported by the Centers for Disease Control and Prevention. Dr. Klein reported receiving grants from Pfizer research support for a COVID vaccine clinical trial as well as other unrelated studies, grants from Merck, grants from GlaxoSmithKline, grants from Sanofi Pasteur, and grants from Protein Science (now Sanofi Pasteur) outside the submitted work.

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

New surveillance data from the Vaccine Adverse Event Reporting System (VAERS) confirm a small but statistically significant increased risk for Guillain-Barré syndrome (GBS) in the 3 weeks after receipt of the Janssen/Johnson & Johnson COVID-19 vaccine.

The Janssen vaccine (Ad26.COV2.S) is a replication-incompetent adenoviral vector vaccine.

The data show no increased risk of GBS with the Pfizer (BNT162b2) or Moderna (mRNA-1273) shots – both mRNA vaccines.

“Our findings support the current guidance from U.S. health officials that preferentially recommend use of mRNA COVID-19 vaccines for primary and booster doses,” Nicola Klein, MD, PhD, with Kaiser Permanente Vaccine Study Center, Oakland, Calif., told this news organization.

“Individuals who choose to receive Janssen/J&J COVID-19 vaccine should be informed of the potential safety risks, including GBS,” Dr. Klein said.

The study was published online in JAMA Network Open.
 

Eleven cases

Between mid-December 2020 and mid-November 2021, roughly 15.1 million doses of COVID-19 vaccine were administered to nearly 7.9 million adults in the United States.

This includes roughly 483,000 doses of the Janssen vaccine, 8.8 million doses of the Pfizer vaccine, and 5.8 million doses of the Moderna vaccine.

The researchers confirmed 11 cases of GBS after the Janssen vaccine.

The unadjusted incidence of GBS (per 100,000 person-years) was 32.4 in the first 21 days after the Janssen vaccine – substantially higher than the expected background rate of 1 to 2 cases per 100,000 person-years.

There were 36 confirmed cases of GBS after mRNA vaccines. The unadjusted incidence in the first 21 days after mRNA vaccination was 1.3 per 100,000 person-years, similar to the overall expected background rate.

In an adjusted head-to-head comparison, GBS incidence during the 21 days after receipt of the Janssen vaccine was 20.6 times higher than the GBS incidence during the 21 days after the Pfizer or Moderna mRNA vaccines, amounting to 15.5 excess cases per million Janssen vaccine recipients.

Most cases of GBS after the Janssen vaccine occurred during the 1- to 21-day risk interval, with the period of greatest risk in the 1-14 days after vaccination.

The findings of this analysis of surveillance data of COVID-19 vaccines are “consistent with an elevated risk of GBS after primary Ad26.COV2.S vaccination,” the authors wrote.
 

Novel presentation?

The researchers note that nearly all individuals who developed GBS after the Janssen vaccine had facial weakness or paralysis, in addition to weakness and decreased reflexes in the limbs, suggesting that the presentation of GBS after COVID-19 adenoviral vector vaccine may be novel.

“More research is needed to determine if the presentation of GBS after adenoviral vector vaccine differs from GBS after other exposures such as Campylobacter jejuni, and to investigate the mechanism for how adenoviral vector vaccines may cause GBS,” Dr. Klein and colleagues said.

“The Vaccine Safety Datalink continues to conduct safety surveillance for all COVID-19 vaccines, including monitoring for GBS and other serious health outcomes after vaccination,” Dr. Klein said in an interview.

This study was supported by the Centers for Disease Control and Prevention. Dr. Klein reported receiving grants from Pfizer research support for a COVID vaccine clinical trial as well as other unrelated studies, grants from Merck, grants from GlaxoSmithKline, grants from Sanofi Pasteur, and grants from Protein Science (now Sanofi Pasteur) outside the submitted work.

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

New surveillance data from the Vaccine Adverse Event Reporting System (VAERS) confirm a small but statistically significant increased risk for Guillain-Barré syndrome (GBS) in the 3 weeks after receipt of the Janssen/Johnson & Johnson COVID-19 vaccine.

The Janssen vaccine (Ad26.COV2.S) is a replication-incompetent adenoviral vector vaccine.

The data show no increased risk of GBS with the Pfizer (BNT162b2) or Moderna (mRNA-1273) shots – both mRNA vaccines.

“Our findings support the current guidance from U.S. health officials that preferentially recommend use of mRNA COVID-19 vaccines for primary and booster doses,” Nicola Klein, MD, PhD, with Kaiser Permanente Vaccine Study Center, Oakland, Calif., told this news organization.

“Individuals who choose to receive Janssen/J&J COVID-19 vaccine should be informed of the potential safety risks, including GBS,” Dr. Klein said.

The study was published online in JAMA Network Open.
 

Eleven cases

Between mid-December 2020 and mid-November 2021, roughly 15.1 million doses of COVID-19 vaccine were administered to nearly 7.9 million adults in the United States.

This includes roughly 483,000 doses of the Janssen vaccine, 8.8 million doses of the Pfizer vaccine, and 5.8 million doses of the Moderna vaccine.

The researchers confirmed 11 cases of GBS after the Janssen vaccine.

The unadjusted incidence of GBS (per 100,000 person-years) was 32.4 in the first 21 days after the Janssen vaccine – substantially higher than the expected background rate of 1 to 2 cases per 100,000 person-years.

There were 36 confirmed cases of GBS after mRNA vaccines. The unadjusted incidence in the first 21 days after mRNA vaccination was 1.3 per 100,000 person-years, similar to the overall expected background rate.

In an adjusted head-to-head comparison, GBS incidence during the 21 days after receipt of the Janssen vaccine was 20.6 times higher than the GBS incidence during the 21 days after the Pfizer or Moderna mRNA vaccines, amounting to 15.5 excess cases per million Janssen vaccine recipients.

Most cases of GBS after the Janssen vaccine occurred during the 1- to 21-day risk interval, with the period of greatest risk in the 1-14 days after vaccination.

The findings of this analysis of surveillance data of COVID-19 vaccines are “consistent with an elevated risk of GBS after primary Ad26.COV2.S vaccination,” the authors wrote.
 

Novel presentation?

The researchers note that nearly all individuals who developed GBS after the Janssen vaccine had facial weakness or paralysis, in addition to weakness and decreased reflexes in the limbs, suggesting that the presentation of GBS after COVID-19 adenoviral vector vaccine may be novel.

“More research is needed to determine if the presentation of GBS after adenoviral vector vaccine differs from GBS after other exposures such as Campylobacter jejuni, and to investigate the mechanism for how adenoviral vector vaccines may cause GBS,” Dr. Klein and colleagues said.

“The Vaccine Safety Datalink continues to conduct safety surveillance for all COVID-19 vaccines, including monitoring for GBS and other serious health outcomes after vaccination,” Dr. Klein said in an interview.

This study was supported by the Centers for Disease Control and Prevention. Dr. Klein reported receiving grants from Pfizer research support for a COVID vaccine clinical trial as well as other unrelated studies, grants from Merck, grants from GlaxoSmithKline, grants from Sanofi Pasteur, and grants from Protein Science (now Sanofi Pasteur) outside the submitted work.

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

Elevated concentrations of carbon monoxide (CO) due to air pollution increases the risk of epileptic seizures, a unique new study suggests.

The link between daily outdoor CO exposure and seizure risk was particularly evident for subclinical seizures – those in patients with abnormal electroencephalography (EEG) signals but no clinical symptoms.

“Our findings suggest that people with epilepsy should avoid high CO exposure to reduce potential seizure risk,” said study investigator Zhuying Chen, PhD candidate, department of biomedical engineering, University of Melbourne.

The study was published online in Epilepsia.
 

Pollution’s impact on brain health

Emerging evidence indicates air pollution affects brain health and may increase the risk of hospitalization or outpatient visits for epilepsy. However, little is known about the effect of pollution on the occurrence of epileptic seizures.

The study used two independent long-term seizure datasets – the NeuroVista (NV) study and the Seer App seizure diary (SD). In the NeuroVista study, researchers recorded continuous intracranial iEEG from patients with refractory focal epilepsy who had been implanted with a personal seizure advisory device that wirelessly recorded seizures on an external device.

The SD dataset included diaries documenting self-reported seizures, seizure cycles, and medication adherence.

Researchers collected data on hourly concentrations of outdoor CO, nitrogen dioxide (NO₂), particulate matter of 10 μm or less in diameter (PM₁₀), ozone (O₃), and sulfur dioxide (SO₂). The levels were measured at air quality monitoring stations in Australia.

Investigators aggregated hourly observations into daily mean data. All daily concentrations of CO and SO₂ and at least 95% of daily concentrations of NO₂, O₃, and PM₁₀ were within Australian air quality standards, said Mr. Chen.

The study included 49 participants, with epilepsy data on 15 patients in the NeuroVista study and on 34 from the SD dataset.

Overall, 6,692 epileptic seizures on 3,639 seizure days were recorded during 23,349 follow-up days from 2010 to 2012 (NV dataset) and 2018 to 2021 (SD dataset).

The investigators found a significant positive association between CO concentrations and epileptic seizure risks. The relative risk (RR) was 1.04 (95% confidence interval, 1.01–1.07; P < .01) for an interquartile range (IQR) increase of CO (0.13 parts per million).
 

Sex differences

There were no significant relationships for the other four air pollutants. However, Mr. Chen noted that Australia has very low air pollution levels; most usually are within World Health Organization air quality guidelines.

“Our findings may not be generalized to other countries with high air pollution levels,” said Mr. Chen. He noted that the relatively small number of patients in the study may limit the statistical power to detect some associations.

The study showed that females had a significantly increased risk of epileptic seizures when exposed to elevated CO (RR, 1.05; 95% CI, 1.01–1.08; P < .05) and NO₂ (RR, 1.09; 95% CI, 1.01–1.16; P < .05) concentrations. There were no significant associations in males for any air pollutants.

Differences in outdoor activities and behaviors such as smoking and exercise may lead to variations in environmental exposure and help explain the sex differences, said Mr. Chen. These differences may also be due to the study’s limited sample size.

Analyzing the two datasets separately, the researchers found there was a significant association between CO concentration and epileptic seizure risk in the NV dataset (RR, 1.10; 95% CI, 1.03–1.17; P < .01).

There were no significant associations in the SD dataset for any air pollutants. This may be because only clinical seizures – those associated with evident symptoms – are self-reported, said Mr. Chen. He also noted that seizure diaries may be unreliable.

In the NV dataset, the epileptic seizure risk was significantly increased when only subclinical seizures were considered (RR, 1.20; 95% CI, 1.12–1.28; P < .001) for an IQR increase of CO concentration.

The risk was significantly decreased by 13% for subclinical seizures with an IQR increase of PM₁₀ and by 9% for subclinical seizures with an IQR increase of SO₂ concentrations.

These negative associations should be interpreted with caution, inasmuch as the associations were not robust in subsequent subgroup and sensitivity analyses, said Mr. Chen.

There were no significant associations when considering clinical seizures for any air pollutants.

The positive association for subclinical but not clinical seizures suggests that low-level CO exposure may not be strong enough to directly trigger clinical seizures, said Mr. Chen.

Although previous research has demonstrated adverse neurologic effects of exposure to air pollutants, most studies were based on hospital databases or registers. Thus, they may have missed seizures that did not lead to hospital admission.
 

Unclear mechanism

The exact mechanisms linking air pollution to seizures are unclear but probably involve the synergistic interaction of multiple pathways, said Mr. Chen. “Air pollution may affect brain metabolism, alter the immune response of the brain, and induce oxidative stress and neuroinflammation, causing the brain to be more susceptible to seizures,” he noted.

This is the first study to investigate seizure rates through intracranial EEG signals and self-reported seizure diaries. It’s also the first to look into the impact of pollutants at low concentration levels on subclinical seizures.

However, the study has some limitations. Self-reported seizures in the SD dataset might underestimate the influence of air pollution on seizures. The study used postal codes as proxies for exposure to pollution, which could introduce measurement errors and underestimate associations.

In addition, Mr. Chen noted that seizures from the NeuroVista dataset were recorded from patients with drug-resistant focal epilepsy. “Whether our findings can be generalized to other epilepsy types needs further investigation.”

The study could have important clinical and public health implications. For example, said Mr. Chen, it’s possible that seizure risk could be reduced through behavioral interventions, such as avoiding being outside or using an air filtration system when pollutant levels are high.

“Clinicians could counsel their patients to avoid the potential risk of high carbon monoxide exposure,” he said.

CO exposure could be a new factor for seizure risk forecasting, which could reduce the uncertainty of seizures and help guide epilepsy management, Mr. Chen added.

The study was supported by the Melbourne Monash Consciousness Research Seed Funding and an Australian National Health and Medical Research Council Ideas grant. Mr. Chen has disclosed no relevant financial relationships.

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

Elevated concentrations of carbon monoxide (CO) due to air pollution increases the risk of epileptic seizures, a unique new study suggests.

The link between daily outdoor CO exposure and seizure risk was particularly evident for subclinical seizures – those in patients with abnormal electroencephalography (EEG) signals but no clinical symptoms.

“Our findings suggest that people with epilepsy should avoid high CO exposure to reduce potential seizure risk,” said study investigator Zhuying Chen, PhD candidate, department of biomedical engineering, University of Melbourne.

The study was published online in Epilepsia.
 

Pollution’s impact on brain health

Emerging evidence indicates air pollution affects brain health and may increase the risk of hospitalization or outpatient visits for epilepsy. However, little is known about the effect of pollution on the occurrence of epileptic seizures.

The study used two independent long-term seizure datasets – the NeuroVista (NV) study and the Seer App seizure diary (SD). In the NeuroVista study, researchers recorded continuous intracranial iEEG from patients with refractory focal epilepsy who had been implanted with a personal seizure advisory device that wirelessly recorded seizures on an external device.

The SD dataset included diaries documenting self-reported seizures, seizure cycles, and medication adherence.

Researchers collected data on hourly concentrations of outdoor CO, nitrogen dioxide (NO₂), particulate matter of 10 μm or less in diameter (PM₁₀), ozone (O₃), and sulfur dioxide (SO₂). The levels were measured at air quality monitoring stations in Australia.

Investigators aggregated hourly observations into daily mean data. All daily concentrations of CO and SO₂ and at least 95% of daily concentrations of NO₂, O₃, and PM₁₀ were within Australian air quality standards, said Mr. Chen.

The study included 49 participants, with epilepsy data on 15 patients in the NeuroVista study and on 34 from the SD dataset.

Overall, 6,692 epileptic seizures on 3,639 seizure days were recorded during 23,349 follow-up days from 2010 to 2012 (NV dataset) and 2018 to 2021 (SD dataset).

The investigators found a significant positive association between CO concentrations and epileptic seizure risks. The relative risk (RR) was 1.04 (95% confidence interval, 1.01–1.07; P < .01) for an interquartile range (IQR) increase of CO (0.13 parts per million).
 

Sex differences

There were no significant relationships for the other four air pollutants. However, Mr. Chen noted that Australia has very low air pollution levels; most usually are within World Health Organization air quality guidelines.

“Our findings may not be generalized to other countries with high air pollution levels,” said Mr. Chen. He noted that the relatively small number of patients in the study may limit the statistical power to detect some associations.

The study showed that females had a significantly increased risk of epileptic seizures when exposed to elevated CO (RR, 1.05; 95% CI, 1.01–1.08; P < .05) and NO₂ (RR, 1.09; 95% CI, 1.01–1.16; P < .05) concentrations. There were no significant associations in males for any air pollutants.

Differences in outdoor activities and behaviors such as smoking and exercise may lead to variations in environmental exposure and help explain the sex differences, said Mr. Chen. These differences may also be due to the study’s limited sample size.

Analyzing the two datasets separately, the researchers found there was a significant association between CO concentration and epileptic seizure risk in the NV dataset (RR, 1.10; 95% CI, 1.03–1.17; P < .01).

There were no significant associations in the SD dataset for any air pollutants. This may be because only clinical seizures – those associated with evident symptoms – are self-reported, said Mr. Chen. He also noted that seizure diaries may be unreliable.

In the NV dataset, the epileptic seizure risk was significantly increased when only subclinical seizures were considered (RR, 1.20; 95% CI, 1.12–1.28; P < .001) for an IQR increase of CO concentration.

The risk was significantly decreased by 13% for subclinical seizures with an IQR increase of PM₁₀ and by 9% for subclinical seizures with an IQR increase of SO₂ concentrations.

These negative associations should be interpreted with caution, inasmuch as the associations were not robust in subsequent subgroup and sensitivity analyses, said Mr. Chen.

There were no significant associations when considering clinical seizures for any air pollutants.

The positive association for subclinical but not clinical seizures suggests that low-level CO exposure may not be strong enough to directly trigger clinical seizures, said Mr. Chen.

Although previous research has demonstrated adverse neurologic effects of exposure to air pollutants, most studies were based on hospital databases or registers. Thus, they may have missed seizures that did not lead to hospital admission.
 

Unclear mechanism

The exact mechanisms linking air pollution to seizures are unclear but probably involve the synergistic interaction of multiple pathways, said Mr. Chen. “Air pollution may affect brain metabolism, alter the immune response of the brain, and induce oxidative stress and neuroinflammation, causing the brain to be more susceptible to seizures,” he noted.

This is the first study to investigate seizure rates through intracranial EEG signals and self-reported seizure diaries. It’s also the first to look into the impact of pollutants at low concentration levels on subclinical seizures.

However, the study has some limitations. Self-reported seizures in the SD dataset might underestimate the influence of air pollution on seizures. The study used postal codes as proxies for exposure to pollution, which could introduce measurement errors and underestimate associations.

In addition, Mr. Chen noted that seizures from the NeuroVista dataset were recorded from patients with drug-resistant focal epilepsy. “Whether our findings can be generalized to other epilepsy types needs further investigation.”

The study could have important clinical and public health implications. For example, said Mr. Chen, it’s possible that seizure risk could be reduced through behavioral interventions, such as avoiding being outside or using an air filtration system when pollutant levels are high.

“Clinicians could counsel their patients to avoid the potential risk of high carbon monoxide exposure,” he said.

CO exposure could be a new factor for seizure risk forecasting, which could reduce the uncertainty of seizures and help guide epilepsy management, Mr. Chen added.

The study was supported by the Melbourne Monash Consciousness Research Seed Funding and an Australian National Health and Medical Research Council Ideas grant. Mr. Chen has disclosed no relevant financial relationships.

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

Elevated concentrations of carbon monoxide (CO) due to air pollution increases the risk of epileptic seizures, a unique new study suggests.

The link between daily outdoor CO exposure and seizure risk was particularly evident for subclinical seizures – those in patients with abnormal electroencephalography (EEG) signals but no clinical symptoms.

“Our findings suggest that people with epilepsy should avoid high CO exposure to reduce potential seizure risk,” said study investigator Zhuying Chen, PhD candidate, department of biomedical engineering, University of Melbourne.

The study was published online in Epilepsia.
 

Pollution’s impact on brain health

Emerging evidence indicates air pollution affects brain health and may increase the risk of hospitalization or outpatient visits for epilepsy. However, little is known about the effect of pollution on the occurrence of epileptic seizures.

The study used two independent long-term seizure datasets – the NeuroVista (NV) study and the Seer App seizure diary (SD). In the NeuroVista study, researchers recorded continuous intracranial iEEG from patients with refractory focal epilepsy who had been implanted with a personal seizure advisory device that wirelessly recorded seizures on an external device.

The SD dataset included diaries documenting self-reported seizures, seizure cycles, and medication adherence.

Researchers collected data on hourly concentrations of outdoor CO, nitrogen dioxide (NO₂), particulate matter of 10 μm or less in diameter (PM₁₀), ozone (O₃), and sulfur dioxide (SO₂). The levels were measured at air quality monitoring stations in Australia.

Investigators aggregated hourly observations into daily mean data. All daily concentrations of CO and SO₂ and at least 95% of daily concentrations of NO₂, O₃, and PM₁₀ were within Australian air quality standards, said Mr. Chen.

The study included 49 participants, with epilepsy data on 15 patients in the NeuroVista study and on 34 from the SD dataset.

Overall, 6,692 epileptic seizures on 3,639 seizure days were recorded during 23,349 follow-up days from 2010 to 2012 (NV dataset) and 2018 to 2021 (SD dataset).

The investigators found a significant positive association between CO concentrations and epileptic seizure risks. The relative risk (RR) was 1.04 (95% confidence interval, 1.01–1.07; P < .01) for an interquartile range (IQR) increase of CO (0.13 parts per million).
 

Sex differences

There were no significant relationships for the other four air pollutants. However, Mr. Chen noted that Australia has very low air pollution levels; most usually are within World Health Organization air quality guidelines.

“Our findings may not be generalized to other countries with high air pollution levels,” said Mr. Chen. He noted that the relatively small number of patients in the study may limit the statistical power to detect some associations.

The study showed that females had a significantly increased risk of epileptic seizures when exposed to elevated CO (RR, 1.05; 95% CI, 1.01–1.08; P < .05) and NO₂ (RR, 1.09; 95% CI, 1.01–1.16; P < .05) concentrations. There were no significant associations in males for any air pollutants.

Differences in outdoor activities and behaviors such as smoking and exercise may lead to variations in environmental exposure and help explain the sex differences, said Mr. Chen. These differences may also be due to the study’s limited sample size.

Analyzing the two datasets separately, the researchers found there was a significant association between CO concentration and epileptic seizure risk in the NV dataset (RR, 1.10; 95% CI, 1.03–1.17; P < .01).

There were no significant associations in the SD dataset for any air pollutants. This may be because only clinical seizures – those associated with evident symptoms – are self-reported, said Mr. Chen. He also noted that seizure diaries may be unreliable.

In the NV dataset, the epileptic seizure risk was significantly increased when only subclinical seizures were considered (RR, 1.20; 95% CI, 1.12–1.28; P < .001) for an IQR increase of CO concentration.

The risk was significantly decreased by 13% for subclinical seizures with an IQR increase of PM₁₀ and by 9% for subclinical seizures with an IQR increase of SO₂ concentrations.

These negative associations should be interpreted with caution, inasmuch as the associations were not robust in subsequent subgroup and sensitivity analyses, said Mr. Chen.

There were no significant associations when considering clinical seizures for any air pollutants.

The positive association for subclinical but not clinical seizures suggests that low-level CO exposure may not be strong enough to directly trigger clinical seizures, said Mr. Chen.

Although previous research has demonstrated adverse neurologic effects of exposure to air pollutants, most studies were based on hospital databases or registers. Thus, they may have missed seizures that did not lead to hospital admission.
 

Unclear mechanism

The exact mechanisms linking air pollution to seizures are unclear but probably involve the synergistic interaction of multiple pathways, said Mr. Chen. “Air pollution may affect brain metabolism, alter the immune response of the brain, and induce oxidative stress and neuroinflammation, causing the brain to be more susceptible to seizures,” he noted.

This is the first study to investigate seizure rates through intracranial EEG signals and self-reported seizure diaries. It’s also the first to look into the impact of pollutants at low concentration levels on subclinical seizures.

However, the study has some limitations. Self-reported seizures in the SD dataset might underestimate the influence of air pollution on seizures. The study used postal codes as proxies for exposure to pollution, which could introduce measurement errors and underestimate associations.

In addition, Mr. Chen noted that seizures from the NeuroVista dataset were recorded from patients with drug-resistant focal epilepsy. “Whether our findings can be generalized to other epilepsy types needs further investigation.”

The study could have important clinical and public health implications. For example, said Mr. Chen, it’s possible that seizure risk could be reduced through behavioral interventions, such as avoiding being outside or using an air filtration system when pollutant levels are high.

“Clinicians could counsel their patients to avoid the potential risk of high carbon monoxide exposure,” he said.

CO exposure could be a new factor for seizure risk forecasting, which could reduce the uncertainty of seizures and help guide epilepsy management, Mr. Chen added.

The study was supported by the Melbourne Monash Consciousness Research Seed Funding and an Australian National Health and Medical Research Council Ideas grant. Mr. Chen has disclosed no relevant financial relationships.

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

Rates of premature return to play (RTP) among student athletes following a sport-related concussion (SRC) have dropped substantially since 2011, according to a recent chart review. Rates of premature return to learn (RTL) are essentially unchanged, however.

“Delay in recovery is the major reason why it’s important not to RTL or RTP prematurely,” said James Carson, MD, associate professor of family and community medicine, University of Toronto.

“That delay in recovery only sets students further back in terms of the stress they get from being delayed with their schoolwork – they could lose their year in school, lose all their social contacts. So, there are a number of psychosocial issues that come into play if recovery is delayed, and that is what premature RTL and premature RTP will do – they delay the student’s recovery,” he emphasized.

The study was published in Canadian Family Physician.
 

Differences by sex

The study involved 241 students who had 258 distinct cases of SRC. The researchers defined premature RTP and RTL as chart records documenting the relapse, recurrence, or worsening of concussion symptoms that accompanied the patient’s RTP or RTL. Between 2011 and 2016, 26.7% of students had evidence of premature RTP, while 42.6% of them had evidence of premature RTL, the authors noted.

Compared with findings from an earlier survey of data from 2006 to 2011, the incidence of premature RTP dropped by 38.6% (P = .0003). In contrast, symptoms associated with premature RTL dropped by only 4.7% from the previous survey. This change was not statistically significant.

There was also a significant difference between males and females in the proportion of SRC cases with relapse of symptoms. Relapse occurred in 43.4% of female athletes with SRC versus 29.7% of male athletes with SRC (P = .023).

Female athletes also had significantly longer times before being cleared for RTP. The mean time was 74.5 days for females, compared with a mean of 42.3 days for male athletes (P < .001). “The median time to RTP clearance was nearly double [for female athletes] at 49 days versus 25 days [for male athletes],” wrote the authors.

The rate of premature RTL was also higher among secondary school students (48.8%), compared with 28% among elementary students and 42% among postsecondary students.
 

More concussions coming?

Before the first consensus conference, organized by the Concussion in Sport Group in 2001, management of concussion was based on rating and grading scales that had no medical evidence to support them, said Dr. Carson. After the consensus conference, it was recommended that physicians manage each concussion individually and, when it came to RTP, recommendations were based upon symptom resolution.

In contrast, there was nothing in the literature regarding how student athletes who sustain a concussion should RTL. Some schools made generous accommodations, and others none. This situation changed around 2011, when experts started publishing data about how better to accommodate student athletes who have a temporary disability for which schools need to introduce temporary accommodations to help them recover.

“Recommendations for RTP essentially had a 12-year head-start,” Dr. Carson emphasized, “and RTL had a much slower start.” Unfortunately, Dr. Carson foresees more athletes sustaining concussions as pandemic restrictions ease over the next few months. “As athletes RTP after the pandemic, they just will not be in game shape,” he said.

“In other words, athletes may not have the neuromuscular control to avoid these injuries as easily,” he added. Worse, athletes may not realize they are not quite ready to return to the expected level of participation so quickly. “I believe this scenario will lead to more concussions that will be difficult to manage in the context of an already strained health care system,” said Dr. Carson.

A limitation of the study was that it was difficult to assess whether all patients followed medical advice consistently.
 

“Very positive shifts”

Commenting on the findings, Nick Reed, PhD, Canada research chair in pediatric concussion and associate professor of occupational science and occupational therapy, University of Toronto, said that sports medicine physicians are seeing “very positive shifts” in concussion awareness and related behaviors such as providing education, support, and accommodations to students within the school environment. “More and more teachers are seeking education to learn what a concussion is and what to do to best support their students with concussion,” he said. Dr. Reed was not involved in the current study.

Indeed, this increasing awareness led to the development of a concussion education tool for teachers – SCHOOLFirst – although Dr. Reed did acknowledge that not all teachers have either the knowledge or the resources they need to optimally support their students with concussion. In the meantime, to reduce the risk of injury, Dr. Reed stressed that it is important for students to wear equipment appropriate for the game being played and to play by the rules.

“It is key to play sports in a way that is fair and respectful and not [engage] in behaviors with the intent of injuring an opponent,” he stressed. It is also important for athletes themselves to know the signs and symptoms of concussion and, if they think they have a concussion, to immediately stop playing, report how they are feeling to a coach, teacher, or parent, and to seek medical assessment to determine if they have a concussion or not.

“The key here is to focus on what the athlete can do after a concussion rather than what they can’t do,” Dr. Reed said. After even a few days of complete rest, students with a concussion can gradually introduce low levels of physical and cognitive activity that won’t make their symptoms worse. This activity can include going back to school with temporary accommodations in place, such as shorter school days and increased rest breaks. “When returning to school and to sport after a concussion, it is important to follow a stepwise and gradual return to activities so that you aren’t doing too much too fast,” Dr. Reed emphasized.

The study was conducted without external funding. Dr. Carson and Dr. Reed reported no conflicts of interest. 

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

Rates of premature return to play (RTP) among student athletes following a sport-related concussion (SRC) have dropped substantially since 2011, according to a recent chart review. Rates of premature return to learn (RTL) are essentially unchanged, however.

“Delay in recovery is the major reason why it’s important not to RTL or RTP prematurely,” said James Carson, MD, associate professor of family and community medicine, University of Toronto.

“That delay in recovery only sets students further back in terms of the stress they get from being delayed with their schoolwork – they could lose their year in school, lose all their social contacts. So, there are a number of psychosocial issues that come into play if recovery is delayed, and that is what premature RTL and premature RTP will do – they delay the student’s recovery,” he emphasized.

The study was published in Canadian Family Physician.
 

Differences by sex

The study involved 241 students who had 258 distinct cases of SRC. The researchers defined premature RTP and RTL as chart records documenting the relapse, recurrence, or worsening of concussion symptoms that accompanied the patient’s RTP or RTL. Between 2011 and 2016, 26.7% of students had evidence of premature RTP, while 42.6% of them had evidence of premature RTL, the authors noted.

Compared with findings from an earlier survey of data from 2006 to 2011, the incidence of premature RTP dropped by 38.6% (P = .0003). In contrast, symptoms associated with premature RTL dropped by only 4.7% from the previous survey. This change was not statistically significant.

There was also a significant difference between males and females in the proportion of SRC cases with relapse of symptoms. Relapse occurred in 43.4% of female athletes with SRC versus 29.7% of male athletes with SRC (P = .023).

Female athletes also had significantly longer times before being cleared for RTP. The mean time was 74.5 days for females, compared with a mean of 42.3 days for male athletes (P < .001). “The median time to RTP clearance was nearly double [for female athletes] at 49 days versus 25 days [for male athletes],” wrote the authors.

The rate of premature RTL was also higher among secondary school students (48.8%), compared with 28% among elementary students and 42% among postsecondary students.
 

More concussions coming?

Before the first consensus conference, organized by the Concussion in Sport Group in 2001, management of concussion was based on rating and grading scales that had no medical evidence to support them, said Dr. Carson. After the consensus conference, it was recommended that physicians manage each concussion individually and, when it came to RTP, recommendations were based upon symptom resolution.

In contrast, there was nothing in the literature regarding how student athletes who sustain a concussion should RTL. Some schools made generous accommodations, and others none. This situation changed around 2011, when experts started publishing data about how better to accommodate student athletes who have a temporary disability for which schools need to introduce temporary accommodations to help them recover.

“Recommendations for RTP essentially had a 12-year head-start,” Dr. Carson emphasized, “and RTL had a much slower start.” Unfortunately, Dr. Carson foresees more athletes sustaining concussions as pandemic restrictions ease over the next few months. “As athletes RTP after the pandemic, they just will not be in game shape,” he said.

“In other words, athletes may not have the neuromuscular control to avoid these injuries as easily,” he added. Worse, athletes may not realize they are not quite ready to return to the expected level of participation so quickly. “I believe this scenario will lead to more concussions that will be difficult to manage in the context of an already strained health care system,” said Dr. Carson.

A limitation of the study was that it was difficult to assess whether all patients followed medical advice consistently.
 

“Very positive shifts”

Commenting on the findings, Nick Reed, PhD, Canada research chair in pediatric concussion and associate professor of occupational science and occupational therapy, University of Toronto, said that sports medicine physicians are seeing “very positive shifts” in concussion awareness and related behaviors such as providing education, support, and accommodations to students within the school environment. “More and more teachers are seeking education to learn what a concussion is and what to do to best support their students with concussion,” he said. Dr. Reed was not involved in the current study.

Indeed, this increasing awareness led to the development of a concussion education tool for teachers – SCHOOLFirst – although Dr. Reed did acknowledge that not all teachers have either the knowledge or the resources they need to optimally support their students with concussion. In the meantime, to reduce the risk of injury, Dr. Reed stressed that it is important for students to wear equipment appropriate for the game being played and to play by the rules.

“It is key to play sports in a way that is fair and respectful and not [engage] in behaviors with the intent of injuring an opponent,” he stressed. It is also important for athletes themselves to know the signs and symptoms of concussion and, if they think they have a concussion, to immediately stop playing, report how they are feeling to a coach, teacher, or parent, and to seek medical assessment to determine if they have a concussion or not.

“The key here is to focus on what the athlete can do after a concussion rather than what they can’t do,” Dr. Reed said. After even a few days of complete rest, students with a concussion can gradually introduce low levels of physical and cognitive activity that won’t make their symptoms worse. This activity can include going back to school with temporary accommodations in place, such as shorter school days and increased rest breaks. “When returning to school and to sport after a concussion, it is important to follow a stepwise and gradual return to activities so that you aren’t doing too much too fast,” Dr. Reed emphasized.

The study was conducted without external funding. Dr. Carson and Dr. Reed reported no conflicts of interest. 

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

Rates of premature return to play (RTP) among student athletes following a sport-related concussion (SRC) have dropped substantially since 2011, according to a recent chart review. Rates of premature return to learn (RTL) are essentially unchanged, however.

“Delay in recovery is the major reason why it’s important not to RTL or RTP prematurely,” said James Carson, MD, associate professor of family and community medicine, University of Toronto.

“That delay in recovery only sets students further back in terms of the stress they get from being delayed with their schoolwork – they could lose their year in school, lose all their social contacts. So, there are a number of psychosocial issues that come into play if recovery is delayed, and that is what premature RTL and premature RTP will do – they delay the student’s recovery,” he emphasized.

The study was published in Canadian Family Physician.
 

Differences by sex

The study involved 241 students who had 258 distinct cases of SRC. The researchers defined premature RTP and RTL as chart records documenting the relapse, recurrence, or worsening of concussion symptoms that accompanied the patient’s RTP or RTL. Between 2011 and 2016, 26.7% of students had evidence of premature RTP, while 42.6% of them had evidence of premature RTL, the authors noted.

Compared with findings from an earlier survey of data from 2006 to 2011, the incidence of premature RTP dropped by 38.6% (P = .0003). In contrast, symptoms associated with premature RTL dropped by only 4.7% from the previous survey. This change was not statistically significant.

There was also a significant difference between males and females in the proportion of SRC cases with relapse of symptoms. Relapse occurred in 43.4% of female athletes with SRC versus 29.7% of male athletes with SRC (P = .023).

Female athletes also had significantly longer times before being cleared for RTP. The mean time was 74.5 days for females, compared with a mean of 42.3 days for male athletes (P < .001). “The median time to RTP clearance was nearly double [for female athletes] at 49 days versus 25 days [for male athletes],” wrote the authors.

The rate of premature RTL was also higher among secondary school students (48.8%), compared with 28% among elementary students and 42% among postsecondary students.
 

More concussions coming?

Before the first consensus conference, organized by the Concussion in Sport Group in 2001, management of concussion was based on rating and grading scales that had no medical evidence to support them, said Dr. Carson. After the consensus conference, it was recommended that physicians manage each concussion individually and, when it came to RTP, recommendations were based upon symptom resolution.

In contrast, there was nothing in the literature regarding how student athletes who sustain a concussion should RTL. Some schools made generous accommodations, and others none. This situation changed around 2011, when experts started publishing data about how better to accommodate student athletes who have a temporary disability for which schools need to introduce temporary accommodations to help them recover.

“Recommendations for RTP essentially had a 12-year head-start,” Dr. Carson emphasized, “and RTL had a much slower start.” Unfortunately, Dr. Carson foresees more athletes sustaining concussions as pandemic restrictions ease over the next few months. “As athletes RTP after the pandemic, they just will not be in game shape,” he said.

“In other words, athletes may not have the neuromuscular control to avoid these injuries as easily,” he added. Worse, athletes may not realize they are not quite ready to return to the expected level of participation so quickly. “I believe this scenario will lead to more concussions that will be difficult to manage in the context of an already strained health care system,” said Dr. Carson.

A limitation of the study was that it was difficult to assess whether all patients followed medical advice consistently.
 

“Very positive shifts”

Commenting on the findings, Nick Reed, PhD, Canada research chair in pediatric concussion and associate professor of occupational science and occupational therapy, University of Toronto, said that sports medicine physicians are seeing “very positive shifts” in concussion awareness and related behaviors such as providing education, support, and accommodations to students within the school environment. “More and more teachers are seeking education to learn what a concussion is and what to do to best support their students with concussion,” he said. Dr. Reed was not involved in the current study.

Indeed, this increasing awareness led to the development of a concussion education tool for teachers – SCHOOLFirst – although Dr. Reed did acknowledge that not all teachers have either the knowledge or the resources they need to optimally support their students with concussion. In the meantime, to reduce the risk of injury, Dr. Reed stressed that it is important for students to wear equipment appropriate for the game being played and to play by the rules.

“It is key to play sports in a way that is fair and respectful and not [engage] in behaviors with the intent of injuring an opponent,” he stressed. It is also important for athletes themselves to know the signs and symptoms of concussion and, if they think they have a concussion, to immediately stop playing, report how they are feeling to a coach, teacher, or parent, and to seek medical assessment to determine if they have a concussion or not.

“The key here is to focus on what the athlete can do after a concussion rather than what they can’t do,” Dr. Reed said. After even a few days of complete rest, students with a concussion can gradually introduce low levels of physical and cognitive activity that won’t make their symptoms worse. This activity can include going back to school with temporary accommodations in place, such as shorter school days and increased rest breaks. “When returning to school and to sport after a concussion, it is important to follow a stepwise and gradual return to activities so that you aren’t doing too much too fast,” Dr. Reed emphasized.

The study was conducted without external funding. Dr. Carson and Dr. Reed reported no conflicts of interest. 

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

Impaired vision in older adults is an underrecognized and modifiable dementia risk factor, new research suggests.

Investigators analyzed estimated population attributable fractions (PAFs) associated with dementia in more than 16,000 older adults. A PAF represents the number of dementia cases that could be prevented if a given risk factor were eliminated.

Results showed the PAF of vision impairment was 1.8%, suggesting that healthy vision had the potential to prevent more than 100,000 cases of dementia in the United States.

“Vision impairment and blindness disproportionately impact older adults, yet vision impairment is often preventable or even correctable,” study investigator Joshua Ehrlich MD, assistant professor of ophthalmology and visual sciences, University of Michigan, Ann Arbor, said in an interview.

Poor vision affects not only how individuals see the world, but also their systemic health and well-being, Dr. Ehrlich said.

“Accordingly, ensuring that older adults receive appropriate eye care is vital to promoting health, independence, and optimal aging,” he added.

The findings were published online in JAMA Neurology.
 

A surprising omission

There is an “urgent need to identify modifiable risk factors for dementia that can be targeted with interventions to slow cognitive decline and prevent dementia,” the investigators wrote.

In 2020, the Lancet Commission report on dementia prevention, intervention, and care proposed a life-course model of 12 potentially modifiable dementia risk factors. This included lower educational level, hearing loss, traumatic brain injury, hypertension, excessive alcohol consumption, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and air pollution.

Together, these factors are associated with about 40% of dementia cases worldwide, the report notes.

Vision impairment was not included in this model, “despite considerable evidence that it is associated with an elevated risk of incident dementia and that it may operate through the same pathways as hearing loss,” the current researchers wrote.

“We have known for some time that vision impairment is a risk factor for dementia [and] we also know that a very large fraction of vision impairment, possibly in excess of 80%, is avoidable or has simply yet to be addressed,” Dr. Ehrlich said.

He and his colleagues found it “surprising that vision impairment had been ignored in key models of modifiable dementia risk factors that are used to shape health policy and resource allocation.” They set out to demonstrate that, “in fact, vision impairment is just as influential as a number of other long accepted modifiable dementia risk factors.”

The investigators assessed data from the Health and Retirement Study (HRS), a panel study that surveys more than 20,000 U.S. adults aged 50 years or older every 2 years.

The investigators applied the same methods used by the Lancet Commission to the HRS dataset and added vision impairment to the Lancet life-course model. Air pollution was excluded in their model “because those data were not readily available in the HRS,” the researchers wrote.

They noted the PAF is “based on the population prevalence and relative risk of dementia for each risk factor” and is “weighted, based on a principal components analysis, to account for communality (clustering of risk factors).”
 

A missed prevention opportunity

The sample included 16,690 participants (54% were women, 51.5% were at least age 65, 80.2% were White, 10.6% were Black, 9.2% were other).

In total, the 12 potentially modifiable risk factors used in the researchers’ model were associated with an estimated 62.4% of dementia cases in the United States, with hypertension as the most prevalent risk factor with the highest weighted PAF.
 

A new focus for prevention

Commenting for this article, Suzann Pershing, MD, associate professor of ophthalmology, Stanford (Calif.) University, called the study “particularly important because, despite growing recognition of its importance in relation to cognition, visual impairment is often an underrecognized risk factor.”

The current research “builds on increasingly robust medical literature linking visual impairment and dementia, applying analogous methods to those used for the life course model recently presented by the Lancet Commission to evaluate potentially modifiable dementia risk factors,” said Dr. Pershing, who was not involved with the study.

The investigators “make a compelling argument for inclusion of visual impairment as one of the potentially modifiable risk factors; practicing clinicians and health care systems may consider screening and targeted therapies to address visual impairment, with a goal of population health and contributing to a reduction in future dementia disease burden,” she added.

In an accompanying editorial), Jennifer Deal, PhD, department of epidemiology and Cochlear Center for Hearing and Public Health, Baltimore, and Julio Rojas, MD, PhD, Memory and Aging Center, department of neurology, Weill Institute for Neurosciences, University of California, San Francisco, call the findings “an important reminder that dementia is a social problem in which potentially treatable risk factors, including visual impairment, are highly prevalent in disadvantaged populations.”

The editorialists noted that 90% of cases of vision impairment are “preventable or have yet to be treated. The two “highly cost-effective interventions” of eyeglasses and/or cataract surgery “remain underused both in the U.S. and globally, especially in disadvantaged communities,” they wrote.

They added that more research is needed to “test the effectiveness of interventions to preserve cognitive health by promoting healthy vision.”

The study was supported by grants from the National Institute on Aging, the National Institutes of Health, and Research to Prevent Blindness. The investigators reported no relevant financial relationships. Dr. Deal reported having received grants from the National Institute on Aging. Dr. Rojas reported serving as site principal investigator on clinical trials for Eli Lilly and Eisai and receiving grants from the National Institute on Aging. Dr. Pershing is a consultant for Acumen, and Verana Health (as DigiSight Technologies).

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

Impaired vision in older adults is an underrecognized and modifiable dementia risk factor, new research suggests.

Investigators analyzed estimated population attributable fractions (PAFs) associated with dementia in more than 16,000 older adults. A PAF represents the number of dementia cases that could be prevented if a given risk factor were eliminated.

Results showed the PAF of vision impairment was 1.8%, suggesting that healthy vision had the potential to prevent more than 100,000 cases of dementia in the United States.

“Vision impairment and blindness disproportionately impact older adults, yet vision impairment is often preventable or even correctable,” study investigator Joshua Ehrlich MD, assistant professor of ophthalmology and visual sciences, University of Michigan, Ann Arbor, said in an interview.

Poor vision affects not only how individuals see the world, but also their systemic health and well-being, Dr. Ehrlich said.

“Accordingly, ensuring that older adults receive appropriate eye care is vital to promoting health, independence, and optimal aging,” he added.

The findings were published online in JAMA Neurology.
 

A surprising omission

There is an “urgent need to identify modifiable risk factors for dementia that can be targeted with interventions to slow cognitive decline and prevent dementia,” the investigators wrote.

In 2020, the Lancet Commission report on dementia prevention, intervention, and care proposed a life-course model of 12 potentially modifiable dementia risk factors. This included lower educational level, hearing loss, traumatic brain injury, hypertension, excessive alcohol consumption, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and air pollution.

Together, these factors are associated with about 40% of dementia cases worldwide, the report notes.

Vision impairment was not included in this model, “despite considerable evidence that it is associated with an elevated risk of incident dementia and that it may operate through the same pathways as hearing loss,” the current researchers wrote.

“We have known for some time that vision impairment is a risk factor for dementia [and] we also know that a very large fraction of vision impairment, possibly in excess of 80%, is avoidable or has simply yet to be addressed,” Dr. Ehrlich said.

He and his colleagues found it “surprising that vision impairment had been ignored in key models of modifiable dementia risk factors that are used to shape health policy and resource allocation.” They set out to demonstrate that, “in fact, vision impairment is just as influential as a number of other long accepted modifiable dementia risk factors.”

The investigators assessed data from the Health and Retirement Study (HRS), a panel study that surveys more than 20,000 U.S. adults aged 50 years or older every 2 years.

The investigators applied the same methods used by the Lancet Commission to the HRS dataset and added vision impairment to the Lancet life-course model. Air pollution was excluded in their model “because those data were not readily available in the HRS,” the researchers wrote.

They noted the PAF is “based on the population prevalence and relative risk of dementia for each risk factor” and is “weighted, based on a principal components analysis, to account for communality (clustering of risk factors).”
 

A missed prevention opportunity

The sample included 16,690 participants (54% were women, 51.5% were at least age 65, 80.2% were White, 10.6% were Black, 9.2% were other).

In total, the 12 potentially modifiable risk factors used in the researchers’ model were associated with an estimated 62.4% of dementia cases in the United States, with hypertension as the most prevalent risk factor with the highest weighted PAF.
 

A new focus for prevention

Commenting for this article, Suzann Pershing, MD, associate professor of ophthalmology, Stanford (Calif.) University, called the study “particularly important because, despite growing recognition of its importance in relation to cognition, visual impairment is often an underrecognized risk factor.”

The current research “builds on increasingly robust medical literature linking visual impairment and dementia, applying analogous methods to those used for the life course model recently presented by the Lancet Commission to evaluate potentially modifiable dementia risk factors,” said Dr. Pershing, who was not involved with the study.

The investigators “make a compelling argument for inclusion of visual impairment as one of the potentially modifiable risk factors; practicing clinicians and health care systems may consider screening and targeted therapies to address visual impairment, with a goal of population health and contributing to a reduction in future dementia disease burden,” she added.

In an accompanying editorial), Jennifer Deal, PhD, department of epidemiology and Cochlear Center for Hearing and Public Health, Baltimore, and Julio Rojas, MD, PhD, Memory and Aging Center, department of neurology, Weill Institute for Neurosciences, University of California, San Francisco, call the findings “an important reminder that dementia is a social problem in which potentially treatable risk factors, including visual impairment, are highly prevalent in disadvantaged populations.”

The editorialists noted that 90% of cases of vision impairment are “preventable or have yet to be treated. The two “highly cost-effective interventions” of eyeglasses and/or cataract surgery “remain underused both in the U.S. and globally, especially in disadvantaged communities,” they wrote.

They added that more research is needed to “test the effectiveness of interventions to preserve cognitive health by promoting healthy vision.”

The study was supported by grants from the National Institute on Aging, the National Institutes of Health, and Research to Prevent Blindness. The investigators reported no relevant financial relationships. Dr. Deal reported having received grants from the National Institute on Aging. Dr. Rojas reported serving as site principal investigator on clinical trials for Eli Lilly and Eisai and receiving grants from the National Institute on Aging. Dr. Pershing is a consultant for Acumen, and Verana Health (as DigiSight Technologies).

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

Impaired vision in older adults is an underrecognized and modifiable dementia risk factor, new research suggests.

Investigators analyzed estimated population attributable fractions (PAFs) associated with dementia in more than 16,000 older adults. A PAF represents the number of dementia cases that could be prevented if a given risk factor were eliminated.

Results showed the PAF of vision impairment was 1.8%, suggesting that healthy vision had the potential to prevent more than 100,000 cases of dementia in the United States.

“Vision impairment and blindness disproportionately impact older adults, yet vision impairment is often preventable or even correctable,” study investigator Joshua Ehrlich MD, assistant professor of ophthalmology and visual sciences, University of Michigan, Ann Arbor, said in an interview.

Poor vision affects not only how individuals see the world, but also their systemic health and well-being, Dr. Ehrlich said.

“Accordingly, ensuring that older adults receive appropriate eye care is vital to promoting health, independence, and optimal aging,” he added.

The findings were published online in JAMA Neurology.
 

A surprising omission

There is an “urgent need to identify modifiable risk factors for dementia that can be targeted with interventions to slow cognitive decline and prevent dementia,” the investigators wrote.

In 2020, the Lancet Commission report on dementia prevention, intervention, and care proposed a life-course model of 12 potentially modifiable dementia risk factors. This included lower educational level, hearing loss, traumatic brain injury, hypertension, excessive alcohol consumption, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and air pollution.

Together, these factors are associated with about 40% of dementia cases worldwide, the report notes.

Vision impairment was not included in this model, “despite considerable evidence that it is associated with an elevated risk of incident dementia and that it may operate through the same pathways as hearing loss,” the current researchers wrote.

“We have known for some time that vision impairment is a risk factor for dementia [and] we also know that a very large fraction of vision impairment, possibly in excess of 80%, is avoidable or has simply yet to be addressed,” Dr. Ehrlich said.

He and his colleagues found it “surprising that vision impairment had been ignored in key models of modifiable dementia risk factors that are used to shape health policy and resource allocation.” They set out to demonstrate that, “in fact, vision impairment is just as influential as a number of other long accepted modifiable dementia risk factors.”

The investigators assessed data from the Health and Retirement Study (HRS), a panel study that surveys more than 20,000 U.S. adults aged 50 years or older every 2 years.

The investigators applied the same methods used by the Lancet Commission to the HRS dataset and added vision impairment to the Lancet life-course model. Air pollution was excluded in their model “because those data were not readily available in the HRS,” the researchers wrote.

They noted the PAF is “based on the population prevalence and relative risk of dementia for each risk factor” and is “weighted, based on a principal components analysis, to account for communality (clustering of risk factors).”
 

A missed prevention opportunity

The sample included 16,690 participants (54% were women, 51.5% were at least age 65, 80.2% were White, 10.6% were Black, 9.2% were other).

In total, the 12 potentially modifiable risk factors used in the researchers’ model were associated with an estimated 62.4% of dementia cases in the United States, with hypertension as the most prevalent risk factor with the highest weighted PAF.
 

A new focus for prevention

Commenting for this article, Suzann Pershing, MD, associate professor of ophthalmology, Stanford (Calif.) University, called the study “particularly important because, despite growing recognition of its importance in relation to cognition, visual impairment is often an underrecognized risk factor.”

The current research “builds on increasingly robust medical literature linking visual impairment and dementia, applying analogous methods to those used for the life course model recently presented by the Lancet Commission to evaluate potentially modifiable dementia risk factors,” said Dr. Pershing, who was not involved with the study.

The investigators “make a compelling argument for inclusion of visual impairment as one of the potentially modifiable risk factors; practicing clinicians and health care systems may consider screening and targeted therapies to address visual impairment, with a goal of population health and contributing to a reduction in future dementia disease burden,” she added.

In an accompanying editorial), Jennifer Deal, PhD, department of epidemiology and Cochlear Center for Hearing and Public Health, Baltimore, and Julio Rojas, MD, PhD, Memory and Aging Center, department of neurology, Weill Institute for Neurosciences, University of California, San Francisco, call the findings “an important reminder that dementia is a social problem in which potentially treatable risk factors, including visual impairment, are highly prevalent in disadvantaged populations.”

The editorialists noted that 90% of cases of vision impairment are “preventable or have yet to be treated. The two “highly cost-effective interventions” of eyeglasses and/or cataract surgery “remain underused both in the U.S. and globally, especially in disadvantaged communities,” they wrote.

They added that more research is needed to “test the effectiveness of interventions to preserve cognitive health by promoting healthy vision.”

The study was supported by grants from the National Institute on Aging, the National Institutes of Health, and Research to Prevent Blindness. The investigators reported no relevant financial relationships. Dr. Deal reported having received grants from the National Institute on Aging. Dr. Rojas reported serving as site principal investigator on clinical trials for Eli Lilly and Eisai and receiving grants from the National Institute on Aging. Dr. Pershing is a consultant for Acumen, and Verana Health (as DigiSight Technologies).

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

Extraverts and individuals who are disciplined are less likely to experience cognitive decline later in life, whereas those with neuroticism have an increased risk for cognitive dysfunction, new research shows.

Investigators analyzed data from almost 2,000 individuals enrolled in the Rush Memory and Aging Project (MAP) – a longitudinal study of older adults living in the greater Chicago metropolitan region and northeastern Illinois – with recruitment that began in 1997 and continues through today. Participants received a personality assessment as well as annual assessments of their cognitive abilities.

Those with high scores on measures of conscientiousness were significantly less likely to progress from normal cognition to mild cognitive impairment (MCI) during the study. In fact, scoring an extra 1 standard deviation on the conscientiousness scale was associated with a 22% lower risk of transitioning from no cognitive impairment (NCI) to MCI. On the other hand, scoring an additional 1 SD on a neuroticism scale was associated with a 12% increased risk of transitioning to MCI.

Participants who scored high on extraversion, as well as those who scored high on conscientiousness or low on neuroticism, tended to maintain normal cognitive functioning longer than other participants.

“Personality traits reflect relatively enduring patterns of thinking and behaving, which may cumulatively affect engagement in healthy and unhealthy behaviors and thought patterns across the lifespan,” lead author Tomiko Yoneda, PhD, a postdoctoral researcher in the department of medical social sciences, Northwestern University, Chicago, said in an interview.

“The accumulation of lifelong experiences may then contribute to susceptibility of particular diseases or disorders, such as mild cognitive impairment, or contribute to individual differences in the ability to withstand age-related neurological changes,” she added.

The study was published online in the Journal of Personality and Social Psychology.
 

Competing risk factors

Personality traits “reflect an individual’s persistent patterns of thinking, feeling, and behaving,” Dr. Yoneda said.

“For example, conscientiousness is characterized by competence, dutifulness, and self-discipline, while neuroticism is characterized by anxiety, depressive symptoms, and emotional instability. Likewise, individuals high in extraversion tend to be enthusiastic, gregarious, talkative, and assertive,” she added.

Previous research “suggests that low conscientiousness and high neuroticism are associated with an increased risk of cognitive impairment,” she continued. However, “there is also an increased risk of death in older adulthood – in other words, these outcomes are ‘competing risk factors.’”

Dr. Yoneda said her team wanted to “examine the impact of personality traits on the simultaneous risk of transitioning to mild cognitive impairment, dementia, and death.”  

For the study, the researchers analyzed data from 1,954 participants in MAP (mean age at baseline 80 years, 73.7% female, 86.8% White), who received a personality assessment and annual assessments of their cognitive abilities.

To assess personality traits – in particular, conscientiousness, neuroticism, and extraversion – the researchers used the NEO Five Factor Inventory (NEO-FFI). They also used multistate survival modeling to examine the potential association between these traits and transitions from one cognitive status category to another (NCI, MCI, and dementia) and to death.
 

Cognitive healthspan

By the end of the study, over half of the sample (54%) had died.

Most transitions showed “relative stability in cognitive status across measurement occasions.”

• NCI to NCI (n = 7,368)
• MCI to MCI (n = 1,244)
• Dementia to dementia (n = 876)

There were 725 “backward transitions” from MCI to NCI, “which may reflect improvement or within-person variability in cognitive functioning, or learning effects,” the authors note.

There were only 114 “backward transitions” from dementia to MCI and only 12 from dementia to NCI, “suggesting that improvement in cognitive status was relatively rare, particularly once an individual progresses to dementia.”

After adjusting for demographics, depressive symptoms, and apolipoprotein (APOE) ε4 allele, the researchers found that personality traits were the most important factors in the transition from NCI to MCI.

Higher conscientiousness was associated with a decreased risk of transitioning from NCI to MCI (hazard ratio, 0.78; 95% confidence interval, 0.72-0.85). Conversely, higher neuroticism was associated with an increased risk of transitioning from NCI to MCI (HR, 1.12; 95% CI, 1.04-1.21) and a significantly decreased likelihood of transition back from MCI to NCI (HR, 0.90; 95% CI, 0.81-1.00).

Scoring ~6 points on a conscientiousness scale ranging from 0-48 (that is, 1 SD on the scale) was significantly associated with ~22% lower risk of transitioning forward from NCI to MCI, while scoring ~7 more points on a neuroticism scale (1 SD) was significantly associated with ~12% higher risk of transitioning from NCI to MCI.

Higher extraversion was associated with an increased likelihood of transitioning from MCI back to NCI (HR, 1.12; 95% CI, 1.03-1.22), and although extraversion was not associated with a longer total lifespan, participants who scored high on extraversion, as well as those who scored low on conscientiousness or low on neuroticism, maintained normal cognitive function longer than other participants.

“Our results suggest that high conscientiousness and low neuroticism may protect individuals against mild cognitive impairment,” said Dr. Yoneda.

Importantly, individuals who were either higher in conscientiousness, higher in extraversion, or lower in neuroticism had more years of “cognitive healthspan,” meaning more years without cognitive impairment,” she added.

In addition, “individuals lower in neuroticism and higher in extraversion were more likely to recover after receiving an MCI diagnosis, suggesting that these traits may be protective even after an individual starts to progress to dementia,” she said.

The authors note that the study focused on only three of the Big Five personality traits, while the other 2 – openness to experience and agreeableness – may also be associated with cognitive aging processes and mortality.

Nevertheless, given the current results, alongside extensive research in the personality field, aiming to increase conscientiousness through persistent behavioral change is one potential strategy for promoting healthy cognitive aging, Dr. Yoneda said.
 

‘Invaluable window’

In a comment, Brent Roberts, PhD, professor of psychology, University of Illinois Urbana-Champaign, said the study provides an “invaluable window into how personality affects the process of decline and either accelerates it, as in the role of neuroticism, or decelerates it, as in the role of conscientiousness.”

“I think the most fascinating finding was the fact that extraversion was related to transitioning from MCI back to NCI. These types of transitions have simply not been part of prior research, and it provides utterly unique insights and opportunities for interventions that may actually help people recover from a decline,” said Dr. Roberts, who was not involved in the research.

Claire Sexton, DPhil, Alzheimer’s Association director of scientific programs and outreach, called the paper “novel” because it investigated the transitions between normal cognition and mild impairment and between mild impairment and dementia.

Dr. Sexton, who was associated with this research team, cautioned that is it observational, “so it can illuminate associations or correlations, but not causes. As a result, we can’t say for sure what the mechanisms are behind these potential connections between personality and cognition, and more research is needed.”

The research was supported by the Alzheimer Society Research Program, Social Sciences and Humanities Research Council, and the National Institute on Aging of the National Institutes of Health. Dr. Yoneda and co-authors, Dr. Roberts, and Dr. Sexton have disclosed no relevant financial relationships.

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

Extraverts and individuals who are disciplined are less likely to experience cognitive decline later in life, whereas those with neuroticism have an increased risk for cognitive dysfunction, new research shows.

Investigators analyzed data from almost 2,000 individuals enrolled in the Rush Memory and Aging Project (MAP) – a longitudinal study of older adults living in the greater Chicago metropolitan region and northeastern Illinois – with recruitment that began in 1997 and continues through today. Participants received a personality assessment as well as annual assessments of their cognitive abilities.

Those with high scores on measures of conscientiousness were significantly less likely to progress from normal cognition to mild cognitive impairment (MCI) during the study. In fact, scoring an extra 1 standard deviation on the conscientiousness scale was associated with a 22% lower risk of transitioning from no cognitive impairment (NCI) to MCI. On the other hand, scoring an additional 1 SD on a neuroticism scale was associated with a 12% increased risk of transitioning to MCI.

Participants who scored high on extraversion, as well as those who scored high on conscientiousness or low on neuroticism, tended to maintain normal cognitive functioning longer than other participants.

“Personality traits reflect relatively enduring patterns of thinking and behaving, which may cumulatively affect engagement in healthy and unhealthy behaviors and thought patterns across the lifespan,” lead author Tomiko Yoneda, PhD, a postdoctoral researcher in the department of medical social sciences, Northwestern University, Chicago, said in an interview.

“The accumulation of lifelong experiences may then contribute to susceptibility of particular diseases or disorders, such as mild cognitive impairment, or contribute to individual differences in the ability to withstand age-related neurological changes,” she added.

The study was published online in the Journal of Personality and Social Psychology.
 

Competing risk factors

Personality traits “reflect an individual’s persistent patterns of thinking, feeling, and behaving,” Dr. Yoneda said.

“For example, conscientiousness is characterized by competence, dutifulness, and self-discipline, while neuroticism is characterized by anxiety, depressive symptoms, and emotional instability. Likewise, individuals high in extraversion tend to be enthusiastic, gregarious, talkative, and assertive,” she added.

Previous research “suggests that low conscientiousness and high neuroticism are associated with an increased risk of cognitive impairment,” she continued. However, “there is also an increased risk of death in older adulthood – in other words, these outcomes are ‘competing risk factors.’”

Dr. Yoneda said her team wanted to “examine the impact of personality traits on the simultaneous risk of transitioning to mild cognitive impairment, dementia, and death.”  

For the study, the researchers analyzed data from 1,954 participants in MAP (mean age at baseline 80 years, 73.7% female, 86.8% White), who received a personality assessment and annual assessments of their cognitive abilities.

To assess personality traits – in particular, conscientiousness, neuroticism, and extraversion – the researchers used the NEO Five Factor Inventory (NEO-FFI). They also used multistate survival modeling to examine the potential association between these traits and transitions from one cognitive status category to another (NCI, MCI, and dementia) and to death.
 

Cognitive healthspan

By the end of the study, over half of the sample (54%) had died.

Most transitions showed “relative stability in cognitive status across measurement occasions.”

• NCI to NCI (n = 7,368)
• MCI to MCI (n = 1,244)
• Dementia to dementia (n = 876)

There were 725 “backward transitions” from MCI to NCI, “which may reflect improvement or within-person variability in cognitive functioning, or learning effects,” the authors note.

There were only 114 “backward transitions” from dementia to MCI and only 12 from dementia to NCI, “suggesting that improvement in cognitive status was relatively rare, particularly once an individual progresses to dementia.”

After adjusting for demographics, depressive symptoms, and apolipoprotein (APOE) ε4 allele, the researchers found that personality traits were the most important factors in the transition from NCI to MCI.

Higher conscientiousness was associated with a decreased risk of transitioning from NCI to MCI (hazard ratio, 0.78; 95% confidence interval, 0.72-0.85). Conversely, higher neuroticism was associated with an increased risk of transitioning from NCI to MCI (HR, 1.12; 95% CI, 1.04-1.21) and a significantly decreased likelihood of transition back from MCI to NCI (HR, 0.90; 95% CI, 0.81-1.00).

Scoring ~6 points on a conscientiousness scale ranging from 0-48 (that is, 1 SD on the scale) was significantly associated with ~22% lower risk of transitioning forward from NCI to MCI, while scoring ~7 more points on a neuroticism scale (1 SD) was significantly associated with ~12% higher risk of transitioning from NCI to MCI.

Higher extraversion was associated with an increased likelihood of transitioning from MCI back to NCI (HR, 1.12; 95% CI, 1.03-1.22), and although extraversion was not associated with a longer total lifespan, participants who scored high on extraversion, as well as those who scored low on conscientiousness or low on neuroticism, maintained normal cognitive function longer than other participants.

“Our results suggest that high conscientiousness and low neuroticism may protect individuals against mild cognitive impairment,” said Dr. Yoneda.

Importantly, individuals who were either higher in conscientiousness, higher in extraversion, or lower in neuroticism had more years of “cognitive healthspan,” meaning more years without cognitive impairment,” she added.

In addition, “individuals lower in neuroticism and higher in extraversion were more likely to recover after receiving an MCI diagnosis, suggesting that these traits may be protective even after an individual starts to progress to dementia,” she said.

The authors note that the study focused on only three of the Big Five personality traits, while the other 2 – openness to experience and agreeableness – may also be associated with cognitive aging processes and mortality.

Nevertheless, given the current results, alongside extensive research in the personality field, aiming to increase conscientiousness through persistent behavioral change is one potential strategy for promoting healthy cognitive aging, Dr. Yoneda said.
 

‘Invaluable window’

In a comment, Brent Roberts, PhD, professor of psychology, University of Illinois Urbana-Champaign, said the study provides an “invaluable window into how personality affects the process of decline and either accelerates it, as in the role of neuroticism, or decelerates it, as in the role of conscientiousness.”

“I think the most fascinating finding was the fact that extraversion was related to transitioning from MCI back to NCI. These types of transitions have simply not been part of prior research, and it provides utterly unique insights and opportunities for interventions that may actually help people recover from a decline,” said Dr. Roberts, who was not involved in the research.

Claire Sexton, DPhil, Alzheimer’s Association director of scientific programs and outreach, called the paper “novel” because it investigated the transitions between normal cognition and mild impairment and between mild impairment and dementia.

Dr. Sexton, who was associated with this research team, cautioned that is it observational, “so it can illuminate associations or correlations, but not causes. As a result, we can’t say for sure what the mechanisms are behind these potential connections between personality and cognition, and more research is needed.”

The research was supported by the Alzheimer Society Research Program, Social Sciences and Humanities Research Council, and the National Institute on Aging of the National Institutes of Health. Dr. Yoneda and co-authors, Dr. Roberts, and Dr. Sexton have disclosed no relevant financial relationships.

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

Extraverts and individuals who are disciplined are less likely to experience cognitive decline later in life, whereas those with neuroticism have an increased risk for cognitive dysfunction, new research shows.

Investigators analyzed data from almost 2,000 individuals enrolled in the Rush Memory and Aging Project (MAP) – a longitudinal study of older adults living in the greater Chicago metropolitan region and northeastern Illinois – with recruitment that began in 1997 and continues through today. Participants received a personality assessment as well as annual assessments of their cognitive abilities.

Those with high scores on measures of conscientiousness were significantly less likely to progress from normal cognition to mild cognitive impairment (MCI) during the study. In fact, scoring an extra 1 standard deviation on the conscientiousness scale was associated with a 22% lower risk of transitioning from no cognitive impairment (NCI) to MCI. On the other hand, scoring an additional 1 SD on a neuroticism scale was associated with a 12% increased risk of transitioning to MCI.

Participants who scored high on extraversion, as well as those who scored high on conscientiousness or low on neuroticism, tended to maintain normal cognitive functioning longer than other participants.

“Personality traits reflect relatively enduring patterns of thinking and behaving, which may cumulatively affect engagement in healthy and unhealthy behaviors and thought patterns across the lifespan,” lead author Tomiko Yoneda, PhD, a postdoctoral researcher in the department of medical social sciences, Northwestern University, Chicago, said in an interview.

“The accumulation of lifelong experiences may then contribute to susceptibility of particular diseases or disorders, such as mild cognitive impairment, or contribute to individual differences in the ability to withstand age-related neurological changes,” she added.

The study was published online in the Journal of Personality and Social Psychology.
 

Competing risk factors

Personality traits “reflect an individual’s persistent patterns of thinking, feeling, and behaving,” Dr. Yoneda said.

“For example, conscientiousness is characterized by competence, dutifulness, and self-discipline, while neuroticism is characterized by anxiety, depressive symptoms, and emotional instability. Likewise, individuals high in extraversion tend to be enthusiastic, gregarious, talkative, and assertive,” she added.

Previous research “suggests that low conscientiousness and high neuroticism are associated with an increased risk of cognitive impairment,” she continued. However, “there is also an increased risk of death in older adulthood – in other words, these outcomes are ‘competing risk factors.’”

Dr. Yoneda said her team wanted to “examine the impact of personality traits on the simultaneous risk of transitioning to mild cognitive impairment, dementia, and death.”  

For the study, the researchers analyzed data from 1,954 participants in MAP (mean age at baseline 80 years, 73.7% female, 86.8% White), who received a personality assessment and annual assessments of their cognitive abilities.

To assess personality traits – in particular, conscientiousness, neuroticism, and extraversion – the researchers used the NEO Five Factor Inventory (NEO-FFI). They also used multistate survival modeling to examine the potential association between these traits and transitions from one cognitive status category to another (NCI, MCI, and dementia) and to death.
 

Cognitive healthspan

By the end of the study, over half of the sample (54%) had died.

Most transitions showed “relative stability in cognitive status across measurement occasions.”

• NCI to NCI (n = 7,368)
• MCI to MCI (n = 1,244)
• Dementia to dementia (n = 876)

There were 725 “backward transitions” from MCI to NCI, “which may reflect improvement or within-person variability in cognitive functioning, or learning effects,” the authors note.

There were only 114 “backward transitions” from dementia to MCI and only 12 from dementia to NCI, “suggesting that improvement in cognitive status was relatively rare, particularly once an individual progresses to dementia.”

After adjusting for demographics, depressive symptoms, and apolipoprotein (APOE) ε4 allele, the researchers found that personality traits were the most important factors in the transition from NCI to MCI.

Higher conscientiousness was associated with a decreased risk of transitioning from NCI to MCI (hazard ratio, 0.78; 95% confidence interval, 0.72-0.85). Conversely, higher neuroticism was associated with an increased risk of transitioning from NCI to MCI (HR, 1.12; 95% CI, 1.04-1.21) and a significantly decreased likelihood of transition back from MCI to NCI (HR, 0.90; 95% CI, 0.81-1.00).

Scoring ~6 points on a conscientiousness scale ranging from 0-48 (that is, 1 SD on the scale) was significantly associated with ~22% lower risk of transitioning forward from NCI to MCI, while scoring ~7 more points on a neuroticism scale (1 SD) was significantly associated with ~12% higher risk of transitioning from NCI to MCI.

Higher extraversion was associated with an increased likelihood of transitioning from MCI back to NCI (HR, 1.12; 95% CI, 1.03-1.22), and although extraversion was not associated with a longer total lifespan, participants who scored high on extraversion, as well as those who scored low on conscientiousness or low on neuroticism, maintained normal cognitive function longer than other participants.

“Our results suggest that high conscientiousness and low neuroticism may protect individuals against mild cognitive impairment,” said Dr. Yoneda.

Importantly, individuals who were either higher in conscientiousness, higher in extraversion, or lower in neuroticism had more years of “cognitive healthspan,” meaning more years without cognitive impairment,” she added.

In addition, “individuals lower in neuroticism and higher in extraversion were more likely to recover after receiving an MCI diagnosis, suggesting that these traits may be protective even after an individual starts to progress to dementia,” she said.

The authors note that the study focused on only three of the Big Five personality traits, while the other 2 – openness to experience and agreeableness – may also be associated with cognitive aging processes and mortality.

Nevertheless, given the current results, alongside extensive research in the personality field, aiming to increase conscientiousness through persistent behavioral change is one potential strategy for promoting healthy cognitive aging, Dr. Yoneda said.
 

‘Invaluable window’

In a comment, Brent Roberts, PhD, professor of psychology, University of Illinois Urbana-Champaign, said the study provides an “invaluable window into how personality affects the process of decline and either accelerates it, as in the role of neuroticism, or decelerates it, as in the role of conscientiousness.”

“I think the most fascinating finding was the fact that extraversion was related to transitioning from MCI back to NCI. These types of transitions have simply not been part of prior research, and it provides utterly unique insights and opportunities for interventions that may actually help people recover from a decline,” said Dr. Roberts, who was not involved in the research.

Claire Sexton, DPhil, Alzheimer’s Association director of scientific programs and outreach, called the paper “novel” because it investigated the transitions between normal cognition and mild impairment and between mild impairment and dementia.

Dr. Sexton, who was associated with this research team, cautioned that is it observational, “so it can illuminate associations or correlations, but not causes. As a result, we can’t say for sure what the mechanisms are behind these potential connections between personality and cognition, and more research is needed.”

The research was supported by the Alzheimer Society Research Program, Social Sciences and Humanities Research Council, and the National Institute on Aging of the National Institutes of Health. Dr. Yoneda and co-authors, Dr. Roberts, and Dr. Sexton have disclosed no relevant financial relationships.

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

Emotional or sexual abuse in childhood may increase risk of multiple sclerosis (MS) in women, and risk may increase further with exposure to multiple kinds of abuse, according to the first prospective cohort study of its kind.

More research is needed to uncover underlying mechanisms of action, according to lead author Karine Eid, MD, a PhD candidate at Haukeland University Hospital, Bergen, Norway, and colleagues.

“Trauma and stressful life events have been associated with an increased risk of autoimmune disorders,” the investigators wrote in the Journal Of Neurology, Neurosurgery, & Psychiatry. “Whether adverse events in childhood can have an impact on MS susceptibility is not known.”

The present study recruited participants from the Norwegian Mother, Father and Child cohort, a population consisting of Norwegian women who were pregnant from 1999 to 2008. Of the 77,997 participating women, 14,477 reported emotional, sexual, and/or physical abuse in childhood, while the remaining 63,520 women reported no abuse. After a mean follow-up of 13 years, 300 women were diagnosed with MS, among whom 24% reported a history of childhood abuse, compared with 19% among women who did not develop MS.

To look for associations between childhood abuse and risk of MS, the investigators used a Cox model adjusted for confounders and mediators, including smoking, obesity, adult socioeconomic factors, and childhood social status. The model revealed that emotional abuse increased the risk of MS by 40% (hazard ratio [HR] 1.40; 95% confidence interval [CI], 1.03-1.90), and sexual abuse increased the risk of MS by 65% (HR 1.65; 95% CI, 1.13-2.39).

Although physical abuse alone did not significantly increase risk of MS (HR 1.31; 95% CI, 0.83-2.06), it did contribute to a dose-response relationship when women were exposed to more than one type of childhood abuse. Women exposed to two out of three abuse categories had a 66% increased risk of MS (HR 1.66; 95% CI, 1.04-2.67), whereas women exposed to all three types of abuse had the highest risk of MS, at 93% (HR 1.93; 95% CI, 1.02-3.67).

Dr. Eid and colleagues noted that their findings are supported by previous retrospective research, and discussed possible mechanisms of action.

“The increased risk of MS after exposure to childhood sexual and emotional abuse may have a biological explanation,” they wrote. “Childhood abuse can cause dysregulation of the hypothalamic-pituitary-adrenal axis, lead to oxidative stress, and induce a proinflammatory state decades into adulthood. Psychological stress has been shown to disrupt the blood-brain barrier and cause epigenetic changes that may increase the risk of neurodegenerative disorders, including MS.

“The underlying mechanisms behind this association should be investigated further,” they concluded.
 

Study findings should guide interventions

Commenting on the research, Ruth Ann Marrie, MD, PhD, professor of medicine and community health sciences and director of the multiple sclerosis clinic at Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, said that the present study “has several strengths compared to prior studies – including that it is prospective and the sample size.”

Dr. Marrie, who was not involved in the study, advised clinicians in the field to take note of the findings, as patients with a history of abuse may need unique interventions.

“Providers need to recognize the higher prevalence of childhood maltreatment in people with MS,” Dr. Marrie said in an interview. “These findings dovetail with others that suggest that adverse childhood experiences are associated with increased mental health concerns and pain catastrophizing in people with MS. Affected individuals may benefit from additional psychological supports and trauma-informed care.”

Tiffany Joy Braley, MD, associate professor of neurology, and Carri Polick, RN and PhD candidate at the school of nursing, University of Michigan, Ann Arbor, who published a case report last year highlighting the importance of evaluating stress exposure in MS, suggested that the findings should guide interventions at both a system and patient level.

“Although a cause-and-effect relationship cannot be established by the current study, these and related findings should be considered in the context of system level and policy interventions that address links between environment and health care disparities,” they said in a joint, written comment. “Given recent impetus to provide trauma-informed health care, these data could be particularly informative in neurological conditions which are associated with high mental health comorbidity. Traumatic stress screening practices could lead to referrals for appropriate support services and more personalized health care.”

While several mechanisms have been proposed to explain the link between traumatic stress and MS, more work is needed in this area, they added.

This knowledge gap was acknowledged by Dr. Marrie.

“Our understanding of the etiology of MS remains incomplete,” Dr. Marrie said. “We still need a better understanding of mechanisms by which adverse childhood experiences lead to MS, how they interact with other risk factors for MS (beyond smoking and obesity), and whether there are any interventions that can mitigate the risk of developing MS that is associated with adverse childhood experiences.”

The investigators disclosed relationships with Novartis, Biogen, Merck, and others. Dr. Marrie receives research support from the Canadian Institutes of Health Research, the National Multiple Sclerosis Society, MS Society of Canada, the Consortium of Multiple Sclerosis Centers, Crohn’s and Colitis Canada, Research Manitoba, and the Arthritis Society; she has no pharmaceutical support. Dr. Braley and Ms. Polick reported no conflicts of interest.

Emotional or sexual abuse in childhood may increase risk of multiple sclerosis (MS) in women, and risk may increase further with exposure to multiple kinds of abuse, according to the first prospective cohort study of its kind.

More research is needed to uncover underlying mechanisms of action, according to lead author Karine Eid, MD, a PhD candidate at Haukeland University Hospital, Bergen, Norway, and colleagues.

“Trauma and stressful life events have been associated with an increased risk of autoimmune disorders,” the investigators wrote in the Journal Of Neurology, Neurosurgery, & Psychiatry. “Whether adverse events in childhood can have an impact on MS susceptibility is not known.”

The present study recruited participants from the Norwegian Mother, Father and Child cohort, a population consisting of Norwegian women who were pregnant from 1999 to 2008. Of the 77,997 participating women, 14,477 reported emotional, sexual, and/or physical abuse in childhood, while the remaining 63,520 women reported no abuse. After a mean follow-up of 13 years, 300 women were diagnosed with MS, among whom 24% reported a history of childhood abuse, compared with 19% among women who did not develop MS.

To look for associations between childhood abuse and risk of MS, the investigators used a Cox model adjusted for confounders and mediators, including smoking, obesity, adult socioeconomic factors, and childhood social status. The model revealed that emotional abuse increased the risk of MS by 40% (hazard ratio [HR] 1.40; 95% confidence interval [CI], 1.03-1.90), and sexual abuse increased the risk of MS by 65% (HR 1.65; 95% CI, 1.13-2.39).

Although physical abuse alone did not significantly increase risk of MS (HR 1.31; 95% CI, 0.83-2.06), it did contribute to a dose-response relationship when women were exposed to more than one type of childhood abuse. Women exposed to two out of three abuse categories had a 66% increased risk of MS (HR 1.66; 95% CI, 1.04-2.67), whereas women exposed to all three types of abuse had the highest risk of MS, at 93% (HR 1.93; 95% CI, 1.02-3.67).

Dr. Eid and colleagues noted that their findings are supported by previous retrospective research, and discussed possible mechanisms of action.

“The increased risk of MS after exposure to childhood sexual and emotional abuse may have a biological explanation,” they wrote. “Childhood abuse can cause dysregulation of the hypothalamic-pituitary-adrenal axis, lead to oxidative stress, and induce a proinflammatory state decades into adulthood. Psychological stress has been shown to disrupt the blood-brain barrier and cause epigenetic changes that may increase the risk of neurodegenerative disorders, including MS.

“The underlying mechanisms behind this association should be investigated further,” they concluded.
 

Study findings should guide interventions

Commenting on the research, Ruth Ann Marrie, MD, PhD, professor of medicine and community health sciences and director of the multiple sclerosis clinic at Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, said that the present study “has several strengths compared to prior studies – including that it is prospective and the sample size.”

Dr. Marrie, who was not involved in the study, advised clinicians in the field to take note of the findings, as patients with a history of abuse may need unique interventions.

“Providers need to recognize the higher prevalence of childhood maltreatment in people with MS,” Dr. Marrie said in an interview. “These findings dovetail with others that suggest that adverse childhood experiences are associated with increased mental health concerns and pain catastrophizing in people with MS. Affected individuals may benefit from additional psychological supports and trauma-informed care.”

Tiffany Joy Braley, MD, associate professor of neurology, and Carri Polick, RN and PhD candidate at the school of nursing, University of Michigan, Ann Arbor, who published a case report last year highlighting the importance of evaluating stress exposure in MS, suggested that the findings should guide interventions at both a system and patient level.

“Although a cause-and-effect relationship cannot be established by the current study, these and related findings should be considered in the context of system level and policy interventions that address links between environment and health care disparities,” they said in a joint, written comment. “Given recent impetus to provide trauma-informed health care, these data could be particularly informative in neurological conditions which are associated with high mental health comorbidity. Traumatic stress screening practices could lead to referrals for appropriate support services and more personalized health care.”

While several mechanisms have been proposed to explain the link between traumatic stress and MS, more work is needed in this area, they added.

This knowledge gap was acknowledged by Dr. Marrie.

“Our understanding of the etiology of MS remains incomplete,” Dr. Marrie said. “We still need a better understanding of mechanisms by which adverse childhood experiences lead to MS, how they interact with other risk factors for MS (beyond smoking and obesity), and whether there are any interventions that can mitigate the risk of developing MS that is associated with adverse childhood experiences.”

The investigators disclosed relationships with Novartis, Biogen, Merck, and others. Dr. Marrie receives research support from the Canadian Institutes of Health Research, the National Multiple Sclerosis Society, MS Society of Canada, the Consortium of Multiple Sclerosis Centers, Crohn’s and Colitis Canada, Research Manitoba, and the Arthritis Society; she has no pharmaceutical support. Dr. Braley and Ms. Polick reported no conflicts of interest.

Emotional or sexual abuse in childhood may increase risk of multiple sclerosis (MS) in women, and risk may increase further with exposure to multiple kinds of abuse, according to the first prospective cohort study of its kind.

More research is needed to uncover underlying mechanisms of action, according to lead author Karine Eid, MD, a PhD candidate at Haukeland University Hospital, Bergen, Norway, and colleagues.

“Trauma and stressful life events have been associated with an increased risk of autoimmune disorders,” the investigators wrote in the Journal Of Neurology, Neurosurgery, & Psychiatry. “Whether adverse events in childhood can have an impact on MS susceptibility is not known.”

The present study recruited participants from the Norwegian Mother, Father and Child cohort, a population consisting of Norwegian women who were pregnant from 1999 to 2008. Of the 77,997 participating women, 14,477 reported emotional, sexual, and/or physical abuse in childhood, while the remaining 63,520 women reported no abuse. After a mean follow-up of 13 years, 300 women were diagnosed with MS, among whom 24% reported a history of childhood abuse, compared with 19% among women who did not develop MS.

To look for associations between childhood abuse and risk of MS, the investigators used a Cox model adjusted for confounders and mediators, including smoking, obesity, adult socioeconomic factors, and childhood social status. The model revealed that emotional abuse increased the risk of MS by 40% (hazard ratio [HR] 1.40; 95% confidence interval [CI], 1.03-1.90), and sexual abuse increased the risk of MS by 65% (HR 1.65; 95% CI, 1.13-2.39).

Although physical abuse alone did not significantly increase risk of MS (HR 1.31; 95% CI, 0.83-2.06), it did contribute to a dose-response relationship when women were exposed to more than one type of childhood abuse. Women exposed to two out of three abuse categories had a 66% increased risk of MS (HR 1.66; 95% CI, 1.04-2.67), whereas women exposed to all three types of abuse had the highest risk of MS, at 93% (HR 1.93; 95% CI, 1.02-3.67).

Dr. Eid and colleagues noted that their findings are supported by previous retrospective research, and discussed possible mechanisms of action.

“The increased risk of MS after exposure to childhood sexual and emotional abuse may have a biological explanation,” they wrote. “Childhood abuse can cause dysregulation of the hypothalamic-pituitary-adrenal axis, lead to oxidative stress, and induce a proinflammatory state decades into adulthood. Psychological stress has been shown to disrupt the blood-brain barrier and cause epigenetic changes that may increase the risk of neurodegenerative disorders, including MS.

“The underlying mechanisms behind this association should be investigated further,” they concluded.
 

Study findings should guide interventions

Commenting on the research, Ruth Ann Marrie, MD, PhD, professor of medicine and community health sciences and director of the multiple sclerosis clinic at Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, said that the present study “has several strengths compared to prior studies – including that it is prospective and the sample size.”

Dr. Marrie, who was not involved in the study, advised clinicians in the field to take note of the findings, as patients with a history of abuse may need unique interventions.

“Providers need to recognize the higher prevalence of childhood maltreatment in people with MS,” Dr. Marrie said in an interview. “These findings dovetail with others that suggest that adverse childhood experiences are associated with increased mental health concerns and pain catastrophizing in people with MS. Affected individuals may benefit from additional psychological supports and trauma-informed care.”

Tiffany Joy Braley, MD, associate professor of neurology, and Carri Polick, RN and PhD candidate at the school of nursing, University of Michigan, Ann Arbor, who published a case report last year highlighting the importance of evaluating stress exposure in MS, suggested that the findings should guide interventions at both a system and patient level.

“Although a cause-and-effect relationship cannot be established by the current study, these and related findings should be considered in the context of system level and policy interventions that address links between environment and health care disparities,” they said in a joint, written comment. “Given recent impetus to provide trauma-informed health care, these data could be particularly informative in neurological conditions which are associated with high mental health comorbidity. Traumatic stress screening practices could lead to referrals for appropriate support services and more personalized health care.”

While several mechanisms have been proposed to explain the link between traumatic stress and MS, more work is needed in this area, they added.

This knowledge gap was acknowledged by Dr. Marrie.

“Our understanding of the etiology of MS remains incomplete,” Dr. Marrie said. “We still need a better understanding of mechanisms by which adverse childhood experiences lead to MS, how they interact with other risk factors for MS (beyond smoking and obesity), and whether there are any interventions that can mitigate the risk of developing MS that is associated with adverse childhood experiences.”

The investigators disclosed relationships with Novartis, Biogen, Merck, and others. Dr. Marrie receives research support from the Canadian Institutes of Health Research, the National Multiple Sclerosis Society, MS Society of Canada, the Consortium of Multiple Sclerosis Centers, Crohn’s and Colitis Canada, Research Manitoba, and the Arthritis Society; she has no pharmaceutical support. Dr. Braley and Ms. Polick reported no conflicts of interest.

Long-term cannabis use is linked to hippocampal atrophy and poorer cognitive function in midlife – known risk factors for dementia.

A large prospective, longitudinal study showed long-term cannabis users had an intelligence quotient (IQ) decline from age 18 to midlife (mean, 5.5 IQ points), poorer learning and processing speed, compared with childhood, and self-reported memory and attention problems. Long-term cannabis users also showed hippocampal atrophy at midlife (age 45), which combined with mild midlife cognitive deficits, all known risk factors for dementia.

“Long-term cannabis users – people who have used cannabis from 18 or 19 years old and continued using through midlife – showed cognitive deficits, compared with nonusers. They also showed more severe cognitive deficits, compared with long-term alcohol users and long-term tobacco users. But people who used infrequently or recreationally in midlife did not show as severe cognitive deficits. Cognitive deficits were confined to cannabis users,” lead investigator Madeline Meier, PhD, associate professor of psychology, Arizona State University, Tempe, said in an interview.

“Long-term cannabis users had smaller hippocampal volume, but we also found that smaller hippocampal volume did not explain the cognitive deficits among the long-term cannabis users,” she added.

The study was recently published online in the American Journal of Psychiatry.
 

Growing use in Boomers

Long-term cannabis use has been associated with memory problems. Studies examining the impact of cannabis use on the brain have shown conflicting results. Some suggest regular use in adolescence is associated with altered connectivity and reduced volume of brain regions involved in executive functions such as memory, learning, and impulse control compared with those who do not use cannabis.

Others found no significant structural differences between the brains of cannabis users and nonusers.

An earlier, large longitudinal study in New Zealand found that persistent cannabis use (with frequent use starting in adolescence) was associated with a loss of an average of six (or up to eight) IQ points measured in mid-adulthood.

Cannabis use is increasing among Baby Boomers – a group born between 1946 and 1964 – who used cannabis at historically high rates as young adults, and who now use it at historically high rates in midlife and as older adults.

To date, case-control studies, which are predominantly in adolescents and young adults, have found that cannabis users show subtle cognitive deficits and structural brain differences, but it is unclear whether these differences in young cannabis users might be larger in midlife and in older adults who have longer histories of use.

The study included a representative cohort of 1,037 individuals in Dunedin, New Zealand, born between April 1972 and March 1973, and followed from age 3 to 45.

Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 

“Most of the previous research has focused on adolescent and young-adult cannabis users. What we’re looking at here is long-term cannabis users in midlife, and we’re finding that long-term users show cognitive deficits. But we’re not just looking at a snapshot of people in midlife, we’re also doing a longitudinal comparison – comparing them to themselves in childhood. We saw that long-term cannabis users showed a decline in IQ from childhood to adulthood,” said Dr. Meier. 

Participants in the study are members of the Dunedin Longitudinal Study, a representative birth cohort (n = 1,037; 91% of eligible births; 52% male) born between April 1972 and March 1973 in Dunedin, New Zealand, who participated in the first assessment at age 3.

This cohort matched socioeconomic status (SES), key health indicators, and demographics. Assessments were carried out at birth and ages 3, 5, 7, 9, 11, 13, 15, 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 
 

Shrinking hippocampal volume

Cannabis use, cognitive function, and hippocampal volume were assessed comparing long-term cannabis users (n = 84) against five distinct groups:

• Lifelong cannabis nonusers (n = 196) – to replicate the control group most often reported in the case-control literature
• Midlife recreational cannabis users (n = 65) – to determine if cognitive deficits and structural brain differences are apparent in nonproblem users – the majority of cannabis users
• Long-term tobacco users (n = 75)
• Long-term alcohol users (n = 57) – benchmark comparisons for any cannabis findings and to disentangle potential cannabis effects from tobacco and alcohol effects
• Cannabis quitters (n = 58) – to determine whether differences are apparent after cessation

Tests were conducted on dose-response associations using continuously measured persistence of cannabis use, rigorously adjusting for numerous confounders derived from multiple longitudinal waves and data sources.

The investigators also tested whether associations between continuously measured persistence of cannabis use and cognitive deficits were mediated by hippocampal volume differences.

The hippocampus was the area of focus because it has a high density of cannabinoid receptors and is also instrumental for learning and memory, which is one of the most consistently impaired cognitive domains in cannabis users, and has been the brain region that most consistently emerges as smaller in cannabis users relative to controls. Structural MRI was done at age 45 for 875 participants (93% of age 45 participants).

Of 997 cohort members still alive at age 45, 938 (94.1%) were assessed at age 45. Age 45 participants did not differ significantly from other participants on childhood SES, childhood self-control, or childhood IQ. Cognitive functioning among midlife recreational cannabis users was similar to representative cohort norms, suggesting that infrequent recreational cannabis use in midlife is unlikely to compromise cognitive functioning.

However, long-term cannabis users did not perform significantly worse on any test than cannabis quitters. Cannabis quitters showed subtle cognitive deficits that may explain inconsistent findings on the benefits of cessation.

Smaller hippocampal volume is thought to be a possible mediator of cannabis-related cognitive deficits because the hippocampus is rich in CB1 receptors and is involved in learning and memory.

Long-term cannabis users had smaller bilateral volume in total hippocampus and 5 of 12 structurally and functionally distinct subregions (tail, hippocampal amygdala transition area, CA1, molecular layer, and dentate gyrus), and significantly smaller volumes than midlife recreational cannabis users in the left and right hippocampus, and 3 of 12 subfields (tail, CA1, and molecular layer), compared with non-users, consistent with case-control studies.
 

More potent

“If you’ve been using cannabis very long term and now are in midlife, you might want to consider quitting. Quitting is associated with slightly better cognitive performance in midlife. We also need to watch for risk of dementia. We know that people who show cognitive deficits at midlife are at elevated risk for later life dementia. And the deficits we saw among long-term cannabis users (although fairly mild), they were in the range in terms of effect size of what we see among people in other studies who have gone on to develop dementia in later life,” said Dr. Meier.

The study findings conflict with those of other studies, including one by the same research group, which compared the cognitive functioning of twins who were discordant for cannabis use and found little evidence of cannabis-related cognitive deficits. Because long-term cannabis users also use tobacco, alcohol, and other illicit drugs, disentangling cannabis effects from other substances is challenging.

“Long-term cannabis users tend to be long-term polysubstance users, so it’s hard to isolate,” said Dr. Meier.

Additionally, some group sizes were small, raising concerns about low statistical power.

“Group sizes were small but we didn’t rely only on those group comparisons; however, we did find statistical differences. We also tested highly statistically powered dose-response associations between persistence of cannabis use over ages 18-45 and each of our outcomes (IQ, learning, and processing speed in midlife) while adjusting possible alternate explanations such as low childhood IQ, other substance use, [and] socioeconomic backgrounds.

“These dose-response associations used large sample sizes, were highly powered, and took into account a number of alternative explanations. These two different approaches showed very similar findings and one bolstered the other,” said Dr. Meier.

The study’s results were based on individuals who began using cannabis in the 1980s or ‘90s, but the concentration of tetrahydrocannabinol (THC) has risen in recent years.

“When the study began, THC concentration was approximately 4%. Over the last decade we have seen it go up to 12% or even higher. A recent study surveying U.S. dispensaries found 20% THC. If THC accounts for impairment, then the effects can be larger [with higher concentrations]. One of the challenges in the U.S. is that there are laws prohibiting researchers from testing cannabis, so we have to rely on product labels, which we know are unreliable,” said Dr. Meier.

A separate report is forthcoming with results of exploratory analyses of associations between long-term cannabis use and comprehensive MRI measures of global and regional gray and white matter.

The data will also be used to answer a number of different questions about cognitive deficits, brain structure, aging preparedness, social preparedness (strength of social networks), financial and health preparedness, and biological aging (the pace of aging relative to chronological age) in long-term cannabis users, Dr. Meier noted.
 

‘Fantastic’ research

Commenting on the research for this news organization , Andrew J. Saxon, MD, professor, department of psychiatry & behavioral sciences at University of Washington, Seattle, and a member of the American Psychiatric Association’s Council on Addiction Psychiatry, said the study “provides more evidence that heavy and regular cannabis use is not benign behavior.”

“It’s a fantastic piece of research in which they enrolled participants at birth and have followed them up to age 45. In most of the other research that has been done, we have no idea what their baseline was. What’s so remarkable here is that they can clearly demonstrate the loss of IQ points from childhood to age 45,” said Dr. Saxon.

“It is clear that, in people using cannabis long term, cognition is impaired. It would be good to have a better handle on how much cognitive function can be regained if you quit, because that could be a motivator for quitting in people where cannabis is having an adverse effect on their lives,” he added.

On the issue of THC potency, Dr. Saxon said that, while it’s true the potency of cannabis is increasing in terms of THC concentrations, the question is: “Do people who use cannabis use a set amount or do they imbibe until they achieve the state of altered consciousness that they’re seeking? Although there has been some research in the area of self-regulation and cannabis potency, we do not yet have the answers to determine if there is any causation,” said Dr. Saxon.

Dr. Meier and Dr. Saxon reported no relevant financial conflicts of interest.

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

Long-term cannabis use is linked to hippocampal atrophy and poorer cognitive function in midlife – known risk factors for dementia.

A large prospective, longitudinal study showed long-term cannabis users had an intelligence quotient (IQ) decline from age 18 to midlife (mean, 5.5 IQ points), poorer learning and processing speed, compared with childhood, and self-reported memory and attention problems. Long-term cannabis users also showed hippocampal atrophy at midlife (age 45), which combined with mild midlife cognitive deficits, all known risk factors for dementia.

“Long-term cannabis users – people who have used cannabis from 18 or 19 years old and continued using through midlife – showed cognitive deficits, compared with nonusers. They also showed more severe cognitive deficits, compared with long-term alcohol users and long-term tobacco users. But people who used infrequently or recreationally in midlife did not show as severe cognitive deficits. Cognitive deficits were confined to cannabis users,” lead investigator Madeline Meier, PhD, associate professor of psychology, Arizona State University, Tempe, said in an interview.

“Long-term cannabis users had smaller hippocampal volume, but we also found that smaller hippocampal volume did not explain the cognitive deficits among the long-term cannabis users,” she added.

The study was recently published online in the American Journal of Psychiatry.
 

Growing use in Boomers

Long-term cannabis use has been associated with memory problems. Studies examining the impact of cannabis use on the brain have shown conflicting results. Some suggest regular use in adolescence is associated with altered connectivity and reduced volume of brain regions involved in executive functions such as memory, learning, and impulse control compared with those who do not use cannabis.

Others found no significant structural differences between the brains of cannabis users and nonusers.

An earlier, large longitudinal study in New Zealand found that persistent cannabis use (with frequent use starting in adolescence) was associated with a loss of an average of six (or up to eight) IQ points measured in mid-adulthood.

Cannabis use is increasing among Baby Boomers – a group born between 1946 and 1964 – who used cannabis at historically high rates as young adults, and who now use it at historically high rates in midlife and as older adults.

To date, case-control studies, which are predominantly in adolescents and young adults, have found that cannabis users show subtle cognitive deficits and structural brain differences, but it is unclear whether these differences in young cannabis users might be larger in midlife and in older adults who have longer histories of use.

The study included a representative cohort of 1,037 individuals in Dunedin, New Zealand, born between April 1972 and March 1973, and followed from age 3 to 45.

Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 

“Most of the previous research has focused on adolescent and young-adult cannabis users. What we’re looking at here is long-term cannabis users in midlife, and we’re finding that long-term users show cognitive deficits. But we’re not just looking at a snapshot of people in midlife, we’re also doing a longitudinal comparison – comparing them to themselves in childhood. We saw that long-term cannabis users showed a decline in IQ from childhood to adulthood,” said Dr. Meier. 

Participants in the study are members of the Dunedin Longitudinal Study, a representative birth cohort (n = 1,037; 91% of eligible births; 52% male) born between April 1972 and March 1973 in Dunedin, New Zealand, who participated in the first assessment at age 3.

This cohort matched socioeconomic status (SES), key health indicators, and demographics. Assessments were carried out at birth and ages 3, 5, 7, 9, 11, 13, 15, 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 
 

Shrinking hippocampal volume

Cannabis use, cognitive function, and hippocampal volume were assessed comparing long-term cannabis users (n = 84) against five distinct groups:

• Lifelong cannabis nonusers (n = 196) – to replicate the control group most often reported in the case-control literature
• Midlife recreational cannabis users (n = 65) – to determine if cognitive deficits and structural brain differences are apparent in nonproblem users – the majority of cannabis users
• Long-term tobacco users (n = 75)
• Long-term alcohol users (n = 57) – benchmark comparisons for any cannabis findings and to disentangle potential cannabis effects from tobacco and alcohol effects
• Cannabis quitters (n = 58) – to determine whether differences are apparent after cessation

Tests were conducted on dose-response associations using continuously measured persistence of cannabis use, rigorously adjusting for numerous confounders derived from multiple longitudinal waves and data sources.

The investigators also tested whether associations between continuously measured persistence of cannabis use and cognitive deficits were mediated by hippocampal volume differences.

The hippocampus was the area of focus because it has a high density of cannabinoid receptors and is also instrumental for learning and memory, which is one of the most consistently impaired cognitive domains in cannabis users, and has been the brain region that most consistently emerges as smaller in cannabis users relative to controls. Structural MRI was done at age 45 for 875 participants (93% of age 45 participants).

Of 997 cohort members still alive at age 45, 938 (94.1%) were assessed at age 45. Age 45 participants did not differ significantly from other participants on childhood SES, childhood self-control, or childhood IQ. Cognitive functioning among midlife recreational cannabis users was similar to representative cohort norms, suggesting that infrequent recreational cannabis use in midlife is unlikely to compromise cognitive functioning.

However, long-term cannabis users did not perform significantly worse on any test than cannabis quitters. Cannabis quitters showed subtle cognitive deficits that may explain inconsistent findings on the benefits of cessation.

Smaller hippocampal volume is thought to be a possible mediator of cannabis-related cognitive deficits because the hippocampus is rich in CB1 receptors and is involved in learning and memory.

Long-term cannabis users had smaller bilateral volume in total hippocampus and 5 of 12 structurally and functionally distinct subregions (tail, hippocampal amygdala transition area, CA1, molecular layer, and dentate gyrus), and significantly smaller volumes than midlife recreational cannabis users in the left and right hippocampus, and 3 of 12 subfields (tail, CA1, and molecular layer), compared with non-users, consistent with case-control studies.
 

More potent

“If you’ve been using cannabis very long term and now are in midlife, you might want to consider quitting. Quitting is associated with slightly better cognitive performance in midlife. We also need to watch for risk of dementia. We know that people who show cognitive deficits at midlife are at elevated risk for later life dementia. And the deficits we saw among long-term cannabis users (although fairly mild), they were in the range in terms of effect size of what we see among people in other studies who have gone on to develop dementia in later life,” said Dr. Meier.

The study findings conflict with those of other studies, including one by the same research group, which compared the cognitive functioning of twins who were discordant for cannabis use and found little evidence of cannabis-related cognitive deficits. Because long-term cannabis users also use tobacco, alcohol, and other illicit drugs, disentangling cannabis effects from other substances is challenging.

“Long-term cannabis users tend to be long-term polysubstance users, so it’s hard to isolate,” said Dr. Meier.

Additionally, some group sizes were small, raising concerns about low statistical power.

“Group sizes were small but we didn’t rely only on those group comparisons; however, we did find statistical differences. We also tested highly statistically powered dose-response associations between persistence of cannabis use over ages 18-45 and each of our outcomes (IQ, learning, and processing speed in midlife) while adjusting possible alternate explanations such as low childhood IQ, other substance use, [and] socioeconomic backgrounds.

“These dose-response associations used large sample sizes, were highly powered, and took into account a number of alternative explanations. These two different approaches showed very similar findings and one bolstered the other,” said Dr. Meier.

The study’s results were based on individuals who began using cannabis in the 1980s or ‘90s, but the concentration of tetrahydrocannabinol (THC) has risen in recent years.

“When the study began, THC concentration was approximately 4%. Over the last decade we have seen it go up to 12% or even higher. A recent study surveying U.S. dispensaries found 20% THC. If THC accounts for impairment, then the effects can be larger [with higher concentrations]. One of the challenges in the U.S. is that there are laws prohibiting researchers from testing cannabis, so we have to rely on product labels, which we know are unreliable,” said Dr. Meier.

A separate report is forthcoming with results of exploratory analyses of associations between long-term cannabis use and comprehensive MRI measures of global and regional gray and white matter.

The data will also be used to answer a number of different questions about cognitive deficits, brain structure, aging preparedness, social preparedness (strength of social networks), financial and health preparedness, and biological aging (the pace of aging relative to chronological age) in long-term cannabis users, Dr. Meier noted.
 

‘Fantastic’ research

Commenting on the research for this news organization , Andrew J. Saxon, MD, professor, department of psychiatry & behavioral sciences at University of Washington, Seattle, and a member of the American Psychiatric Association’s Council on Addiction Psychiatry, said the study “provides more evidence that heavy and regular cannabis use is not benign behavior.”

“It’s a fantastic piece of research in which they enrolled participants at birth and have followed them up to age 45. In most of the other research that has been done, we have no idea what their baseline was. What’s so remarkable here is that they can clearly demonstrate the loss of IQ points from childhood to age 45,” said Dr. Saxon.

“It is clear that, in people using cannabis long term, cognition is impaired. It would be good to have a better handle on how much cognitive function can be regained if you quit, because that could be a motivator for quitting in people where cannabis is having an adverse effect on their lives,” he added.

On the issue of THC potency, Dr. Saxon said that, while it’s true the potency of cannabis is increasing in terms of THC concentrations, the question is: “Do people who use cannabis use a set amount or do they imbibe until they achieve the state of altered consciousness that they’re seeking? Although there has been some research in the area of self-regulation and cannabis potency, we do not yet have the answers to determine if there is any causation,” said Dr. Saxon.

Dr. Meier and Dr. Saxon reported no relevant financial conflicts of interest.

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

Long-term cannabis use is linked to hippocampal atrophy and poorer cognitive function in midlife – known risk factors for dementia.

A large prospective, longitudinal study showed long-term cannabis users had an intelligence quotient (IQ) decline from age 18 to midlife (mean, 5.5 IQ points), poorer learning and processing speed, compared with childhood, and self-reported memory and attention problems. Long-term cannabis users also showed hippocampal atrophy at midlife (age 45), which combined with mild midlife cognitive deficits, all known risk factors for dementia.

“Long-term cannabis users – people who have used cannabis from 18 or 19 years old and continued using through midlife – showed cognitive deficits, compared with nonusers. They also showed more severe cognitive deficits, compared with long-term alcohol users and long-term tobacco users. But people who used infrequently or recreationally in midlife did not show as severe cognitive deficits. Cognitive deficits were confined to cannabis users,” lead investigator Madeline Meier, PhD, associate professor of psychology, Arizona State University, Tempe, said in an interview.

“Long-term cannabis users had smaller hippocampal volume, but we also found that smaller hippocampal volume did not explain the cognitive deficits among the long-term cannabis users,” she added.

The study was recently published online in the American Journal of Psychiatry.
 

Growing use in Boomers

Long-term cannabis use has been associated with memory problems. Studies examining the impact of cannabis use on the brain have shown conflicting results. Some suggest regular use in adolescence is associated with altered connectivity and reduced volume of brain regions involved in executive functions such as memory, learning, and impulse control compared with those who do not use cannabis.

Others found no significant structural differences between the brains of cannabis users and nonusers.

An earlier, large longitudinal study in New Zealand found that persistent cannabis use (with frequent use starting in adolescence) was associated with a loss of an average of six (or up to eight) IQ points measured in mid-adulthood.

Cannabis use is increasing among Baby Boomers – a group born between 1946 and 1964 – who used cannabis at historically high rates as young adults, and who now use it at historically high rates in midlife and as older adults.

To date, case-control studies, which are predominantly in adolescents and young adults, have found that cannabis users show subtle cognitive deficits and structural brain differences, but it is unclear whether these differences in young cannabis users might be larger in midlife and in older adults who have longer histories of use.

The study included a representative cohort of 1,037 individuals in Dunedin, New Zealand, born between April 1972 and March 1973, and followed from age 3 to 45.

Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 

“Most of the previous research has focused on adolescent and young-adult cannabis users. What we’re looking at here is long-term cannabis users in midlife, and we’re finding that long-term users show cognitive deficits. But we’re not just looking at a snapshot of people in midlife, we’re also doing a longitudinal comparison – comparing them to themselves in childhood. We saw that long-term cannabis users showed a decline in IQ from childhood to adulthood,” said Dr. Meier. 

Participants in the study are members of the Dunedin Longitudinal Study, a representative birth cohort (n = 1,037; 91% of eligible births; 52% male) born between April 1972 and March 1973 in Dunedin, New Zealand, who participated in the first assessment at age 3.

This cohort matched socioeconomic status (SES), key health indicators, and demographics. Assessments were carried out at birth and ages 3, 5, 7, 9, 11, 13, 15, 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. 
 

Shrinking hippocampal volume

Cannabis use, cognitive function, and hippocampal volume were assessed comparing long-term cannabis users (n = 84) against five distinct groups:

• Lifelong cannabis nonusers (n = 196) – to replicate the control group most often reported in the case-control literature
• Midlife recreational cannabis users (n = 65) – to determine if cognitive deficits and structural brain differences are apparent in nonproblem users – the majority of cannabis users
• Long-term tobacco users (n = 75)
• Long-term alcohol users (n = 57) – benchmark comparisons for any cannabis findings and to disentangle potential cannabis effects from tobacco and alcohol effects
• Cannabis quitters (n = 58) – to determine whether differences are apparent after cessation

Tests were conducted on dose-response associations using continuously measured persistence of cannabis use, rigorously adjusting for numerous confounders derived from multiple longitudinal waves and data sources.

The investigators also tested whether associations between continuously measured persistence of cannabis use and cognitive deficits were mediated by hippocampal volume differences.

The hippocampus was the area of focus because it has a high density of cannabinoid receptors and is also instrumental for learning and memory, which is one of the most consistently impaired cognitive domains in cannabis users, and has been the brain region that most consistently emerges as smaller in cannabis users relative to controls. Structural MRI was done at age 45 for 875 participants (93% of age 45 participants).

Of 997 cohort members still alive at age 45, 938 (94.1%) were assessed at age 45. Age 45 participants did not differ significantly from other participants on childhood SES, childhood self-control, or childhood IQ. Cognitive functioning among midlife recreational cannabis users was similar to representative cohort norms, suggesting that infrequent recreational cannabis use in midlife is unlikely to compromise cognitive functioning.

However, long-term cannabis users did not perform significantly worse on any test than cannabis quitters. Cannabis quitters showed subtle cognitive deficits that may explain inconsistent findings on the benefits of cessation.

Smaller hippocampal volume is thought to be a possible mediator of cannabis-related cognitive deficits because the hippocampus is rich in CB1 receptors and is involved in learning and memory.

Long-term cannabis users had smaller bilateral volume in total hippocampus and 5 of 12 structurally and functionally distinct subregions (tail, hippocampal amygdala transition area, CA1, molecular layer, and dentate gyrus), and significantly smaller volumes than midlife recreational cannabis users in the left and right hippocampus, and 3 of 12 subfields (tail, CA1, and molecular layer), compared with non-users, consistent with case-control studies.
 

More potent

“If you’ve been using cannabis very long term and now are in midlife, you might want to consider quitting. Quitting is associated with slightly better cognitive performance in midlife. We also need to watch for risk of dementia. We know that people who show cognitive deficits at midlife are at elevated risk for later life dementia. And the deficits we saw among long-term cannabis users (although fairly mild), they were in the range in terms of effect size of what we see among people in other studies who have gone on to develop dementia in later life,” said Dr. Meier.

The study findings conflict with those of other studies, including one by the same research group, which compared the cognitive functioning of twins who were discordant for cannabis use and found little evidence of cannabis-related cognitive deficits. Because long-term cannabis users also use tobacco, alcohol, and other illicit drugs, disentangling cannabis effects from other substances is challenging.

“Long-term cannabis users tend to be long-term polysubstance users, so it’s hard to isolate,” said Dr. Meier.

Additionally, some group sizes were small, raising concerns about low statistical power.

“Group sizes were small but we didn’t rely only on those group comparisons; however, we did find statistical differences. We also tested highly statistically powered dose-response associations between persistence of cannabis use over ages 18-45 and each of our outcomes (IQ, learning, and processing speed in midlife) while adjusting possible alternate explanations such as low childhood IQ, other substance use, [and] socioeconomic backgrounds.

“These dose-response associations used large sample sizes, were highly powered, and took into account a number of alternative explanations. These two different approaches showed very similar findings and one bolstered the other,” said Dr. Meier.

The study’s results were based on individuals who began using cannabis in the 1980s or ‘90s, but the concentration of tetrahydrocannabinol (THC) has risen in recent years.

“When the study began, THC concentration was approximately 4%. Over the last decade we have seen it go up to 12% or even higher. A recent study surveying U.S. dispensaries found 20% THC. If THC accounts for impairment, then the effects can be larger [with higher concentrations]. One of the challenges in the U.S. is that there are laws prohibiting researchers from testing cannabis, so we have to rely on product labels, which we know are unreliable,” said Dr. Meier.

A separate report is forthcoming with results of exploratory analyses of associations between long-term cannabis use and comprehensive MRI measures of global and regional gray and white matter.

The data will also be used to answer a number of different questions about cognitive deficits, brain structure, aging preparedness, social preparedness (strength of social networks), financial and health preparedness, and biological aging (the pace of aging relative to chronological age) in long-term cannabis users, Dr. Meier noted.
 

‘Fantastic’ research

Commenting on the research for this news organization , Andrew J. Saxon, MD, professor, department of psychiatry & behavioral sciences at University of Washington, Seattle, and a member of the American Psychiatric Association’s Council on Addiction Psychiatry, said the study “provides more evidence that heavy and regular cannabis use is not benign behavior.”

“It’s a fantastic piece of research in which they enrolled participants at birth and have followed them up to age 45. In most of the other research that has been done, we have no idea what their baseline was. What’s so remarkable here is that they can clearly demonstrate the loss of IQ points from childhood to age 45,” said Dr. Saxon.

“It is clear that, in people using cannabis long term, cognition is impaired. It would be good to have a better handle on how much cognitive function can be regained if you quit, because that could be a motivator for quitting in people where cannabis is having an adverse effect on their lives,” he added.

On the issue of THC potency, Dr. Saxon said that, while it’s true the potency of cannabis is increasing in terms of THC concentrations, the question is: “Do people who use cannabis use a set amount or do they imbibe until they achieve the state of altered consciousness that they’re seeking? Although there has been some research in the area of self-regulation and cannabis potency, we do not yet have the answers to determine if there is any causation,” said Dr. Saxon.

Dr. Meier and Dr. Saxon reported no relevant financial conflicts of interest.

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