Kerri Wachter

The number of cancer survivors in the United States rose from 3 million in 1971 and 9.8 million in 2001 to 11.5 million in 2007, according to a new report by the Centers for Disease Control and Prevention and the National Cancer Institute.

The numbers come from the study “Cancer Survivors in the United States, 2007” (MMWR 2011;60:269-72). The study authors defined a cancer survivor as “a person living with a history of cancer.”

The new numbers highlight the need for more research on the unique physical, psychological, and social issues facing cancer survivors. There is now “a growing number of people who have faced a cancer diagnosis which affects them and their loved ones – from the time of diagnosis through the rest of their lives,” the NCI's Julia H. Rowland, Ph.D., said in a press release.

“Unfortunately for many cancer survivors and those around them, the effect of cancer does not end with the last treatment. … This report underscores the need for continued research, as well as for the development and implementation of best practices to provide optimal care and support for all cancer survivors,” said Dr. Rowland, director of the NCI's Office of Cancer Survivorship.

The study authors analyzed the number of new cancer cases (except in situ and nonmelanoma skin cancers) as well as follow-up data from the NCI's SEER (Surveillance, Epidemiology and End Results) program in 1971–2006. They estimated the number of persons who were ever diagnosed with cancer and were alive on Jan. 1, 2007 (MMWR 2011;60:269-72).

Notably, 65% of cancer survivors on Jan. 1, 2007, received their diagnosis at least 5 years earlier. Also, people aged 65 years or older accounted for 60%. The largest group of cancer survivors was breast cancer survivors (22%), followed by prostate cancer survivors (19%) and colorectal cancer survivors (10%). Women accounted for slightly more than half (54%) of all survivors.

Clinicians can find research tools, publications and other resources through the NCI's Office of Cancer Survivorship at http://cancercontrol.cancer.gov/ocs/

The number of cancer survivors in the United States rose from 3 million in 1971 and 9.8 million in 2001 to 11.5 million in 2007, according to a new report by the Centers for Disease Control and Prevention and the National Cancer Institute.

The numbers come from the study “Cancer Survivors in the United States, 2007” (MMWR 2011;60:269-72). The study authors defined a cancer survivor as “a person living with a history of cancer.”

The new numbers highlight the need for more research on the unique physical, psychological, and social issues facing cancer survivors. There is now “a growing number of people who have faced a cancer diagnosis which affects them and their loved ones – from the time of diagnosis through the rest of their lives,” the NCI's Julia H. Rowland, Ph.D., said in a press release.

“Unfortunately for many cancer survivors and those around them, the effect of cancer does not end with the last treatment. … This report underscores the need for continued research, as well as for the development and implementation of best practices to provide optimal care and support for all cancer survivors,” said Dr. Rowland, director of the NCI's Office of Cancer Survivorship.

The study authors analyzed the number of new cancer cases (except in situ and nonmelanoma skin cancers) as well as follow-up data from the NCI's SEER (Surveillance, Epidemiology and End Results) program in 1971–2006. They estimated the number of persons who were ever diagnosed with cancer and were alive on Jan. 1, 2007 (MMWR 2011;60:269-72).

Notably, 65% of cancer survivors on Jan. 1, 2007, received their diagnosis at least 5 years earlier. Also, people aged 65 years or older accounted for 60%. The largest group of cancer survivors was breast cancer survivors (22%), followed by prostate cancer survivors (19%) and colorectal cancer survivors (10%). Women accounted for slightly more than half (54%) of all survivors.

Clinicians can find research tools, publications and other resources through the NCI's Office of Cancer Survivorship at http://cancercontrol.cancer.gov/ocs/

The number of cancer survivors in the United States rose from 3 million in 1971 and 9.8 million in 2001 to 11.5 million in 2007, according to a new report by the Centers for Disease Control and Prevention and the National Cancer Institute.

The numbers come from the study “Cancer Survivors in the United States, 2007” (MMWR 2011;60:269-72). The study authors defined a cancer survivor as “a person living with a history of cancer.”

The new numbers highlight the need for more research on the unique physical, psychological, and social issues facing cancer survivors. There is now “a growing number of people who have faced a cancer diagnosis which affects them and their loved ones – from the time of diagnosis through the rest of their lives,” the NCI's Julia H. Rowland, Ph.D., said in a press release.

“Unfortunately for many cancer survivors and those around them, the effect of cancer does not end with the last treatment. … This report underscores the need for continued research, as well as for the development and implementation of best practices to provide optimal care and support for all cancer survivors,” said Dr. Rowland, director of the NCI's Office of Cancer Survivorship.

The study authors analyzed the number of new cancer cases (except in situ and nonmelanoma skin cancers) as well as follow-up data from the NCI's SEER (Surveillance, Epidemiology and End Results) program in 1971–2006. They estimated the number of persons who were ever diagnosed with cancer and were alive on Jan. 1, 2007 (MMWR 2011;60:269-72).

Notably, 65% of cancer survivors on Jan. 1, 2007, received their diagnosis at least 5 years earlier. Also, people aged 65 years or older accounted for 60%. The largest group of cancer survivors was breast cancer survivors (22%), followed by prostate cancer survivors (19%) and colorectal cancer survivors (10%). Women accounted for slightly more than half (54%) of all survivors.

Clinicians can find research tools, publications and other resources through the NCI's Office of Cancer Survivorship at http://cancercontrol.cancer.gov/ocs/

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study in 6,700 Dutch women aged 46–57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994–1995. The WHILA Study comprises 6,917 Swedish women aged 50–64 years who participated in a health screening procedure that took place between 1996 and 2000. Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

Women who reported that they had no VMS were used as the reference category in Cox regression analyses based on a mean follow-up of 10.3 years. In total, 48% of all women reported flushing and 35% reported night sweats. The overall mean age at baseline was 53 years but the WHILA cohort was older than the EPOS cohort. During follow-up, 303 women had an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht (Netherlands), and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively. Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not linked with risk of CHD in this group. However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote. They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Greater sympathetic nervous activity may explain the night sweats/CHD link.

Source ©Getty Images/Linda Braucht

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study in 6,700 Dutch women aged 46–57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994–1995. The WHILA Study comprises 6,917 Swedish women aged 50–64 years who participated in a health screening procedure that took place between 1996 and 2000. Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

Women who reported that they had no VMS were used as the reference category in Cox regression analyses based on a mean follow-up of 10.3 years. In total, 48% of all women reported flushing and 35% reported night sweats. The overall mean age at baseline was 53 years but the WHILA cohort was older than the EPOS cohort. During follow-up, 303 women had an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht (Netherlands), and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively. Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not linked with risk of CHD in this group. However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote. They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Greater sympathetic nervous activity may explain the night sweats/CHD link.

Source ©Getty Images/Linda Braucht

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study in 6,700 Dutch women aged 46–57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994–1995. The WHILA Study comprises 6,917 Swedish women aged 50–64 years who participated in a health screening procedure that took place between 1996 and 2000. Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

Women who reported that they had no VMS were used as the reference category in Cox regression analyses based on a mean follow-up of 10.3 years. In total, 48% of all women reported flushing and 35% reported night sweats. The overall mean age at baseline was 53 years but the WHILA cohort was older than the EPOS cohort. During follow-up, 303 women had an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht (Netherlands), and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively. Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not linked with risk of CHD in this group. However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote. They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Greater sympathetic nervous activity may explain the night sweats/CHD link.

Source ©Getty Images/Linda Braucht

Breastfeeding appears to have a protective effect against later obesity for children born to mothers with diabetes during pregnancy, based on an analysis of data from a retrospective cohort study.

The findings could help to prevent childhood obesity in children born to mothers with diabetes during pregnancy. Research has shown that these children have a greater prevalence of obesity in childhood, Tessa L. Crume, Ph.D., of the Colorado School of Public Health at the University of Colorado in Denver and her coinvestigators noted (Diabetes Care 2011;34:641-5).

Both children exposed to diabetes in utero and those unexposed but who had adequate breastfeeding had significantly lower body mass index (BMI), waist circumference, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) at ages 6–13 years than did those who breastfed less.

“Our study provides novel evidence that the effect of exposure to diabetes in utero on childhood adiposity parameters is substantially attenuated by breastfeeding, such that the obesity outcomes in exposed youth who were adequately breastfed were similar to those of unexposed youth. Our data suggest that breastfeeding promotion may be an effective strategy for reducing the increased risk of childhood obesity in the offspring of mothers with diabetes during pregnancy,” wrote Dr. Crume and her colleagues.

The researchers used data from a retrospective cohort study entitled Exploring Perinatal Outcomes Among Children (EPOCH). Participants were aged 6–13 years. In addition, they were multiethnic offspring of singleton pregnancies born at a single hospital in Denver between 1992 and 2002. The mothers were members of the Kaiser Permanente of Colorado Health Plan and were still members and living in Colorado over the study period (2006–2009).

The study included 89 youths who were exposed to diabetes in utero. The researchers also identified a random sample of 397 children who were not exposed to diabetes in utero. Children and their biologic mothers were invited for a research visit during January 2006 to October 2009.

Physician-diagnosed maternal diabetes status was ascertained from the Kaiser Permanente Colorado perinatal database – an electronic database linking neonatal and perinatal medical records. All pregnant women were offered screening at 24–28 weeks. Exposure to diabetes in utero was defined as the presence of preexistent diabetes or gestational diabetes diagnosed during the index pregnancy. Birth weight, gestational age, and maternal prepregnancy weight also were obtained from the database.

Mothers were asked about breastfeeding and formula feeding, timing, and the introduction of other solid foods and beverages. Mixed feeding was commonly reported, so a measure of breast milk-months was developed that incorporated duration and exclusivity. Based on a formula that included those factors, breastfeeding status was categorized as low (less than 6 breast milk-months) and adequate (at least 6 breast milk-months).

The subscapular-to-triceps skinfold ratio (STR) was calculated to assess regional differences in subcutaneous fat distribution. In addition, an MRI of the abdominal region was used to quantify VAT and SAT.

The mean age was 9.6 years for exposed youth and 10.6 years for unexposed youth at the study visit – a difference that was significant. Exposed youth were significantly more likely to be non-Hispanic white or Hispanic, and a larger proportion of exposed youth self-reported a Tanner stage less than 2 (prepubertal). Mothers with diabetes during pregnancy were significantly older on average than mothers whose pregnancies were not complicated by diabetes. Exposed and unexposed offspring were not significantly different in terms of intrauterine growth, socioeconomic factors, or infant feeding practices.

Among adolescents with low breastfeeding status, exposure to diabetes in utero was associated with a 1.7-kg/m

The authors reported that they have no relevant financial disclosures.

View on the News

Study Supports Breastfeeding

Dr. Andreas Plagemann and Dr. Thomas Harder noted that these findings may help answer key questions for the rapidly expanding fields of perinatal programming and developmental origins of health and disease.

“Differentiation and maturation, however, of affected organs and systems, such as the pancreas, adipose tissue, and brain, are not finished at birth. The question therefore arises whether a prolongation of these critical exposures into the neonatal period might have similar effects,” they wrote.

The question of whether continuing exposure after birth to altered fuels through breastfeeding might have consequences for child development. “This study by Crume et al. further supports the notion that a long-term breastfeeding (i.e., longer than 6 months) has a protective effect on later overweight risk in [offspring of diabetic mothers],” they wrote.

DR. PLAGEMANN is head of the division of experimental obstetrics at Charité-University Medicine Berlin. DR. HARDER also is a member of that organization. They reported that they had no relevant financial relationships. They commented in an editorial that accompanied the article by Crume et al. (Diabetes Care 2011;34:779-81).

Breastfeeding appears to have a protective effect against later obesity for children born to mothers with diabetes during pregnancy, based on an analysis of data from a retrospective cohort study.

The findings could help to prevent childhood obesity in children born to mothers with diabetes during pregnancy. Research has shown that these children have a greater prevalence of obesity in childhood, Tessa L. Crume, Ph.D., of the Colorado School of Public Health at the University of Colorado in Denver and her coinvestigators noted (Diabetes Care 2011;34:641-5).

Both children exposed to diabetes in utero and those unexposed but who had adequate breastfeeding had significantly lower body mass index (BMI), waist circumference, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) at ages 6–13 years than did those who breastfed less.

“Our study provides novel evidence that the effect of exposure to diabetes in utero on childhood adiposity parameters is substantially attenuated by breastfeeding, such that the obesity outcomes in exposed youth who were adequately breastfed were similar to those of unexposed youth. Our data suggest that breastfeeding promotion may be an effective strategy for reducing the increased risk of childhood obesity in the offspring of mothers with diabetes during pregnancy,” wrote Dr. Crume and her colleagues.

The researchers used data from a retrospective cohort study entitled Exploring Perinatal Outcomes Among Children (EPOCH). Participants were aged 6–13 years. In addition, they were multiethnic offspring of singleton pregnancies born at a single hospital in Denver between 1992 and 2002. The mothers were members of the Kaiser Permanente of Colorado Health Plan and were still members and living in Colorado over the study period (2006–2009).

The study included 89 youths who were exposed to diabetes in utero. The researchers also identified a random sample of 397 children who were not exposed to diabetes in utero. Children and their biologic mothers were invited for a research visit during January 2006 to October 2009.

Physician-diagnosed maternal diabetes status was ascertained from the Kaiser Permanente Colorado perinatal database – an electronic database linking neonatal and perinatal medical records. All pregnant women were offered screening at 24–28 weeks. Exposure to diabetes in utero was defined as the presence of preexistent diabetes or gestational diabetes diagnosed during the index pregnancy. Birth weight, gestational age, and maternal prepregnancy weight also were obtained from the database.

Mothers were asked about breastfeeding and formula feeding, timing, and the introduction of other solid foods and beverages. Mixed feeding was commonly reported, so a measure of breast milk-months was developed that incorporated duration and exclusivity. Based on a formula that included those factors, breastfeeding status was categorized as low (less than 6 breast milk-months) and adequate (at least 6 breast milk-months).

The subscapular-to-triceps skinfold ratio (STR) was calculated to assess regional differences in subcutaneous fat distribution. In addition, an MRI of the abdominal region was used to quantify VAT and SAT.

The mean age was 9.6 years for exposed youth and 10.6 years for unexposed youth at the study visit – a difference that was significant. Exposed youth were significantly more likely to be non-Hispanic white or Hispanic, and a larger proportion of exposed youth self-reported a Tanner stage less than 2 (prepubertal). Mothers with diabetes during pregnancy were significantly older on average than mothers whose pregnancies were not complicated by diabetes. Exposed and unexposed offspring were not significantly different in terms of intrauterine growth, socioeconomic factors, or infant feeding practices.

Among adolescents with low breastfeeding status, exposure to diabetes in utero was associated with a 1.7-kg/m

The authors reported that they have no relevant financial disclosures.

View on the News

Study Supports Breastfeeding

Dr. Andreas Plagemann and Dr. Thomas Harder noted that these findings may help answer key questions for the rapidly expanding fields of perinatal programming and developmental origins of health and disease.

“Differentiation and maturation, however, of affected organs and systems, such as the pancreas, adipose tissue, and brain, are not finished at birth. The question therefore arises whether a prolongation of these critical exposures into the neonatal period might have similar effects,” they wrote.

The question of whether continuing exposure after birth to altered fuels through breastfeeding might have consequences for child development. “This study by Crume et al. further supports the notion that a long-term breastfeeding (i.e., longer than 6 months) has a protective effect on later overweight risk in [offspring of diabetic mothers],” they wrote.

DR. PLAGEMANN is head of the division of experimental obstetrics at Charité-University Medicine Berlin. DR. HARDER also is a member of that organization. They reported that they had no relevant financial relationships. They commented in an editorial that accompanied the article by Crume et al. (Diabetes Care 2011;34:779-81).

Breastfeeding appears to have a protective effect against later obesity for children born to mothers with diabetes during pregnancy, based on an analysis of data from a retrospective cohort study.

The findings could help to prevent childhood obesity in children born to mothers with diabetes during pregnancy. Research has shown that these children have a greater prevalence of obesity in childhood, Tessa L. Crume, Ph.D., of the Colorado School of Public Health at the University of Colorado in Denver and her coinvestigators noted (Diabetes Care 2011;34:641-5).

Both children exposed to diabetes in utero and those unexposed but who had adequate breastfeeding had significantly lower body mass index (BMI), waist circumference, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) at ages 6–13 years than did those who breastfed less.

“Our study provides novel evidence that the effect of exposure to diabetes in utero on childhood adiposity parameters is substantially attenuated by breastfeeding, such that the obesity outcomes in exposed youth who were adequately breastfed were similar to those of unexposed youth. Our data suggest that breastfeeding promotion may be an effective strategy for reducing the increased risk of childhood obesity in the offspring of mothers with diabetes during pregnancy,” wrote Dr. Crume and her colleagues.

The researchers used data from a retrospective cohort study entitled Exploring Perinatal Outcomes Among Children (EPOCH). Participants were aged 6–13 years. In addition, they were multiethnic offspring of singleton pregnancies born at a single hospital in Denver between 1992 and 2002. The mothers were members of the Kaiser Permanente of Colorado Health Plan and were still members and living in Colorado over the study period (2006–2009).

The study included 89 youths who were exposed to diabetes in utero. The researchers also identified a random sample of 397 children who were not exposed to diabetes in utero. Children and their biologic mothers were invited for a research visit during January 2006 to October 2009.

Physician-diagnosed maternal diabetes status was ascertained from the Kaiser Permanente Colorado perinatal database – an electronic database linking neonatal and perinatal medical records. All pregnant women were offered screening at 24–28 weeks. Exposure to diabetes in utero was defined as the presence of preexistent diabetes or gestational diabetes diagnosed during the index pregnancy. Birth weight, gestational age, and maternal prepregnancy weight also were obtained from the database.

Mothers were asked about breastfeeding and formula feeding, timing, and the introduction of other solid foods and beverages. Mixed feeding was commonly reported, so a measure of breast milk-months was developed that incorporated duration and exclusivity. Based on a formula that included those factors, breastfeeding status was categorized as low (less than 6 breast milk-months) and adequate (at least 6 breast milk-months).

The subscapular-to-triceps skinfold ratio (STR) was calculated to assess regional differences in subcutaneous fat distribution. In addition, an MRI of the abdominal region was used to quantify VAT and SAT.

The mean age was 9.6 years for exposed youth and 10.6 years for unexposed youth at the study visit – a difference that was significant. Exposed youth were significantly more likely to be non-Hispanic white or Hispanic, and a larger proportion of exposed youth self-reported a Tanner stage less than 2 (prepubertal). Mothers with diabetes during pregnancy were significantly older on average than mothers whose pregnancies were not complicated by diabetes. Exposed and unexposed offspring were not significantly different in terms of intrauterine growth, socioeconomic factors, or infant feeding practices.

Among adolescents with low breastfeeding status, exposure to diabetes in utero was associated with a 1.7-kg/m

The authors reported that they have no relevant financial disclosures.

View on the News

Study Supports Breastfeeding

Dr. Andreas Plagemann and Dr. Thomas Harder noted that these findings may help answer key questions for the rapidly expanding fields of perinatal programming and developmental origins of health and disease.

“Differentiation and maturation, however, of affected organs and systems, such as the pancreas, adipose tissue, and brain, are not finished at birth. The question therefore arises whether a prolongation of these critical exposures into the neonatal period might have similar effects,” they wrote.

The question of whether continuing exposure after birth to altered fuels through breastfeeding might have consequences for child development. “This study by Crume et al. further supports the notion that a long-term breastfeeding (i.e., longer than 6 months) has a protective effect on later overweight risk in [offspring of diabetic mothers],” they wrote.

DR. PLAGEMANN is head of the division of experimental obstetrics at Charité-University Medicine Berlin. DR. HARDER also is a member of that organization. They reported that they had no relevant financial relationships. They commented in an editorial that accompanied the article by Crume et al. (Diabetes Care 2011;34:779-81).

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study among 6,700 Dutch women aged 46-57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994-1995. The WHILA Study comprises 6,917 Swedish women aged 50-64 years who participated in a health screening procedure that took place between 1996 and 2000.

Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

The association between VMS and incident CHD was investigated using Cox regression models; women who reported that they had no VMS were used as the reference category. The analyses were based on a mean follow-up of 10.3 years. In total, 48% of all women reported symptoms of flushing and 35% reported symptoms of night sweats. The overall mean age at baseline was 53 years but the mean baseline age was greater in the WHILA cohort than in the EPOS cohort. Women in the EPOS cohort were more likely to have a medium level of completed education and to be current smokers. All other variables were similar for both cohorts. During follow-up, 303 women experienced an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht in the Netherlands, and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively.

Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not associated with risk of CHD in this group.

However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote.

They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Vitals

Source ©Getty Images/Linda Braucht

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study among 6,700 Dutch women aged 46-57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994-1995. The WHILA Study comprises 6,917 Swedish women aged 50-64 years who participated in a health screening procedure that took place between 1996 and 2000.

Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

The association between VMS and incident CHD was investigated using Cox regression models; women who reported that they had no VMS were used as the reference category. The analyses were based on a mean follow-up of 10.3 years. In total, 48% of all women reported symptoms of flushing and 35% reported symptoms of night sweats. The overall mean age at baseline was 53 years but the mean baseline age was greater in the WHILA cohort than in the EPOS cohort. Women in the EPOS cohort were more likely to have a medium level of completed education and to be current smokers. All other variables were similar for both cohorts. During follow-up, 303 women experienced an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht in the Netherlands, and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively.

Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not associated with risk of CHD in this group.

However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote.

They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Vitals

Source ©Getty Images/Linda Braucht

Major Finding: In menopausal women, night sweats were associated with an increased risk of coronary heart disease in analyses adjusted for age (HR, 1.39), multiple variables (HR, 1.33), and cardiovascular risk factors (HR, 1.25). There was no link with hot flushes.

Data Source: An analysis of 10,787 women in two large cohort studies.

Disclosures: The authors did not disclose any financial conflicts of interest.

Night sweats, but not hot flushes, appear to significantly increase the risk of coronary heart disease, based on the results of an analysis of more than 10,000 women in Sweden and the Netherlands.

“Our data show that women with night sweats have a 33% increased CHD risk as compared with asymptomatic women. [Body mass index], blood pressure, and total cholesterol level could not totally explain this association, because after adjustment for these factors, symptoms of night sweats were still associated with a slightly, borderline significantly increased risk of CHD,” wrote Gerrie-Cor M. Gast, Ph.D., and her coinvestigators (Menopause 2011;18:146-51).

The researchers merged two large cohorts of women of menopausal age – the Eindhoven Perimenopausal Osteoporosis Study (EPOS) and the Women's Health in the Lund Area (WHILA) study – to examine possible associations between menopausal vasomotor symptoms (VMS) and risk of CHD. EPOS is a prospective cohort study among 6,700 Dutch women aged 46-57 years, who participated in a screening program established to assess determinants of low bone mineral density during 1994-1995. The WHILA Study comprises 6,917 Swedish women aged 50-64 years who participated in a health screening procedure that took place between 1996 and 2000.

Women with prevalent cases of CHD were excluded, leaving in 10,787 women for the analysis (4,790 from EPOS and 5,997 from WHILA). Both studies were linked to databases that allowed the researchers to gather information about causes of death.

The association between VMS and incident CHD was investigated using Cox regression models; women who reported that they had no VMS were used as the reference category. The analyses were based on a mean follow-up of 10.3 years. In total, 48% of all women reported symptoms of flushing and 35% reported symptoms of night sweats. The overall mean age at baseline was 53 years but the mean baseline age was greater in the WHILA cohort than in the EPOS cohort. Women in the EPOS cohort were more likely to have a medium level of completed education and to be current smokers. All other variables were similar for both cohorts. During follow-up, 303 women experienced an incident CHD event, of which 14 were fatal, noted Dr. Gast, a researcher at the University Medical Center Utrecht in the Netherlands, and her coinvestigators.

The presence of flushing was not associated with risk of CHD (hazard ratio, 1.11). This did not change after multivariable adjustment. However, in the age-adjusted and multivariable-adjusted analyses, the occurrence of night sweats was associated with a significantly increased risk of CHD, with hazard ratios of 1.39 and 1.33, respectively.

Importantly, adjustment for BMI, blood pressure, and total cholesterol level attenuated the association, but symptoms of night sweats were still associated with a slightly, borderline significantly, increased risk of CHD (HR, 1.25).

To minimize the possibility that the use of exogenous hormones modified the risk of CHD, the researchers conducted a separate analysis for the subgroup of 7,100 women who had never used oral contraceptives or hormone therapy. Symptoms of flushing were not associated with risk of CHD in this group.

However, night sweats were still positively and even more strongly associated with a significantly increased CHD risk in the age-adjusted model (HR, 1.46) and multivariable-adjusted model (HR, 1.44) – as well as in the analyses, in which the researchers adjusted for BMI, blood pressure, and total cholesterol (HR, 1.35).

“We do not have a clear pathophysiological explanation for our finding,” the researchers wrote.

They speculated that “a possible mechanism linking night sweats to CHD is the sympathetic nervous system activity, which is thought to be higher in the symptomatic women. An increase in sympathetic nervous system activity is also involved in various vascular abnormalities. Conceivably, this may explain the higher CHD risk in women with night sweats.”

Vitals

Source ©Getty Images/Linda Braucht

Major Finding: In the short term, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19), and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Data Source: A meta-analysis of data from 163 randomized controlled trials with 50,010 adult participants and 46 extension studies with 11,954 adult participants.

Disclosures: Dr. Singh and several of his coauthors reported that they have significant financial relationships with several pharmaceutical companies.

Biologics appear to be associated with a significantly greater rate of total adverse events, withdrawals due to adverse events, and an increased risk of tuberculosis reactivation compared with control agents, based on a meta-analysis involving more than 60,000 patients.

However, there were no significant differences in the rates of serious adverse events, serious infections, lymphoma, and congestive heart failure between biologics and control agents, wrote Dr. Jasvinder A. Singh and his coauthors (Cochrane Database Syst. Rev. 2011 [doi: 10.1002/14651858.CD008794.pub2]); http://www2.cochrane.org/reviews/en/ab008794.html

The results come from a network meta-analysis and Cochrane overview of the adverse effects of biologic drugs that are approved for the treatment of rheumatoid arthritis and other conditions in Europe, the United Kingdom, the United States, Canada, and Australia.

The investigators included randomized controlled trials (RCTs), controlled clinical trials, and open-label extension studies that involved one of the nine biologics for use in any indication and that reported this study's prespecified adverse outcomes. The researchers did not include studies on biologics for the treatment of HIV/AIDS. The nine biologics investigated were abatacept (Orencia), adalimumab (Humira), anakinra (Kineret), certolizumab pegol (Cimzia), etanercept (Enbrel), golimumab (Simponi), infliximab (Remicade), rituximab (Rituxan/MabThera), and tocilizumab (Actemra). They searched the Cochrane Library, Medline, and Embase (through January 2010).

The investigators performed mixed-effects logistic regression using an arm-based, random-effects model within an empirical Bayes framework for the network meta-analysis.

In all, included in the analysis were 163 RCTs with 50,010 adult participants and 46 extension studies with 11,954 adult participants. The median duration was 6 months for the RCTs and 13 months for the extension studies. Given the short duration of the RCTs, all the results should be interpreted as applying to a fairly short time frame.

After the analysis was adjusted for dose, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19) and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Certolizumab pegol was associated with a significantly greater risk of serious infections than was control treatment (OR 3.51), according to the report. Infliximab was associated with a significantly greater risk of withdrawals due to adverse events compared with the control (OR 2.04).

Heart failure and cancer have been of particular concern with the use of biologic drugs.

There appears to be little or no difference in the number of people who experienced heart failure or cancer taking any biologic compared with people who took placebo. However, there were not many cases of congestive heart failure or cancer, so confidence in these results is low.

The researchers also were able to indirectly compare individual biologics.

These analyses revealed that abatacept and anakinra were associated with a significantly lower risk of serious adverse events than were most other biologics. In addition, certolizumab pegol was associated with significantly greater odds of serious infections than were etanercept, adalimumab, abatacept, anakinra, golimumab, infliximab, and rituximab. Abatacept was significantly less likely than infliximab and tocilizumab to be associated with serious infections; abatacept, adalimumab, etanercept, and golimumab were significantly less likely than infliximab to result in withdrawals due to adverse events.

“There is an urgent need for more research regarding the long-term safety of biologics and the comparative safety of different biologics,” they concluded.

Major Finding: In the short term, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19), and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Data Source: A meta-analysis of data from 163 randomized controlled trials with 50,010 adult participants and 46 extension studies with 11,954 adult participants.

Disclosures: Dr. Singh and several of his coauthors reported that they have significant financial relationships with several pharmaceutical companies.

Biologics appear to be associated with a significantly greater rate of total adverse events, withdrawals due to adverse events, and an increased risk of tuberculosis reactivation compared with control agents, based on a meta-analysis involving more than 60,000 patients.

However, there were no significant differences in the rates of serious adverse events, serious infections, lymphoma, and congestive heart failure between biologics and control agents, wrote Dr. Jasvinder A. Singh and his coauthors (Cochrane Database Syst. Rev. 2011 [doi: 10.1002/14651858.CD008794.pub2]); http://www2.cochrane.org/reviews/en/ab008794.html

The results come from a network meta-analysis and Cochrane overview of the adverse effects of biologic drugs that are approved for the treatment of rheumatoid arthritis and other conditions in Europe, the United Kingdom, the United States, Canada, and Australia.

The investigators included randomized controlled trials (RCTs), controlled clinical trials, and open-label extension studies that involved one of the nine biologics for use in any indication and that reported this study's prespecified adverse outcomes. The researchers did not include studies on biologics for the treatment of HIV/AIDS. The nine biologics investigated were abatacept (Orencia), adalimumab (Humira), anakinra (Kineret), certolizumab pegol (Cimzia), etanercept (Enbrel), golimumab (Simponi), infliximab (Remicade), rituximab (Rituxan/MabThera), and tocilizumab (Actemra). They searched the Cochrane Library, Medline, and Embase (through January 2010).

The investigators performed mixed-effects logistic regression using an arm-based, random-effects model within an empirical Bayes framework for the network meta-analysis.

In all, included in the analysis were 163 RCTs with 50,010 adult participants and 46 extension studies with 11,954 adult participants. The median duration was 6 months for the RCTs and 13 months for the extension studies. Given the short duration of the RCTs, all the results should be interpreted as applying to a fairly short time frame.

After the analysis was adjusted for dose, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19) and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Certolizumab pegol was associated with a significantly greater risk of serious infections than was control treatment (OR 3.51), according to the report. Infliximab was associated with a significantly greater risk of withdrawals due to adverse events compared with the control (OR 2.04).

Heart failure and cancer have been of particular concern with the use of biologic drugs.

There appears to be little or no difference in the number of people who experienced heart failure or cancer taking any biologic compared with people who took placebo. However, there were not many cases of congestive heart failure or cancer, so confidence in these results is low.

The researchers also were able to indirectly compare individual biologics.

These analyses revealed that abatacept and anakinra were associated with a significantly lower risk of serious adverse events than were most other biologics. In addition, certolizumab pegol was associated with significantly greater odds of serious infections than were etanercept, adalimumab, abatacept, anakinra, golimumab, infliximab, and rituximab. Abatacept was significantly less likely than infliximab and tocilizumab to be associated with serious infections; abatacept, adalimumab, etanercept, and golimumab were significantly less likely than infliximab to result in withdrawals due to adverse events.

“There is an urgent need for more research regarding the long-term safety of biologics and the comparative safety of different biologics,” they concluded.

Major Finding: In the short term, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19), and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Data Source: A meta-analysis of data from 163 randomized controlled trials with 50,010 adult participants and 46 extension studies with 11,954 adult participants.

Disclosures: Dr. Singh and several of his coauthors reported that they have significant financial relationships with several pharmaceutical companies.

Biologics appear to be associated with a significantly greater rate of total adverse events, withdrawals due to adverse events, and an increased risk of tuberculosis reactivation compared with control agents, based on a meta-analysis involving more than 60,000 patients.

However, there were no significant differences in the rates of serious adverse events, serious infections, lymphoma, and congestive heart failure between biologics and control agents, wrote Dr. Jasvinder A. Singh and his coauthors (Cochrane Database Syst. Rev. 2011 [doi: 10.1002/14651858.CD008794.pub2]); http://www2.cochrane.org/reviews/en/ab008794.html

The results come from a network meta-analysis and Cochrane overview of the adverse effects of biologic drugs that are approved for the treatment of rheumatoid arthritis and other conditions in Europe, the United Kingdom, the United States, Canada, and Australia.

The investigators included randomized controlled trials (RCTs), controlled clinical trials, and open-label extension studies that involved one of the nine biologics for use in any indication and that reported this study's prespecified adverse outcomes. The researchers did not include studies on biologics for the treatment of HIV/AIDS. The nine biologics investigated were abatacept (Orencia), adalimumab (Humira), anakinra (Kineret), certolizumab pegol (Cimzia), etanercept (Enbrel), golimumab (Simponi), infliximab (Remicade), rituximab (Rituxan/MabThera), and tocilizumab (Actemra). They searched the Cochrane Library, Medline, and Embase (through January 2010).

The investigators performed mixed-effects logistic regression using an arm-based, random-effects model within an empirical Bayes framework for the network meta-analysis.

In all, included in the analysis were 163 RCTs with 50,010 adult participants and 46 extension studies with 11,954 adult participants. The median duration was 6 months for the RCTs and 13 months for the extension studies. Given the short duration of the RCTs, all the results should be interpreted as applying to a fairly short time frame.

After the analysis was adjusted for dose, biologics as a group were associated with a significantly greater rate of total adverse events (odds ratio 1.19) and withdrawals due to adverse events (OR 1.32), as well as an increased risk of TB reactivation (OR 4.68), compared with control agents.

Certolizumab pegol was associated with a significantly greater risk of serious infections than was control treatment (OR 3.51), according to the report. Infliximab was associated with a significantly greater risk of withdrawals due to adverse events compared with the control (OR 2.04).

Heart failure and cancer have been of particular concern with the use of biologic drugs.

There appears to be little or no difference in the number of people who experienced heart failure or cancer taking any biologic compared with people who took placebo. However, there were not many cases of congestive heart failure or cancer, so confidence in these results is low.

The researchers also were able to indirectly compare individual biologics.

These analyses revealed that abatacept and anakinra were associated with a significantly lower risk of serious adverse events than were most other biologics. In addition, certolizumab pegol was associated with significantly greater odds of serious infections than were etanercept, adalimumab, abatacept, anakinra, golimumab, infliximab, and rituximab. Abatacept was significantly less likely than infliximab and tocilizumab to be associated with serious infections; abatacept, adalimumab, etanercept, and golimumab were significantly less likely than infliximab to result in withdrawals due to adverse events.

“There is an urgent need for more research regarding the long-term safety of biologics and the comparative safety of different biologics,” they concluded.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Ionizing radiation from backscatter x-ray scanners deployed at airports around the United States pose little cancer risk. In fact, the flight itself poses a greater radiation risk, according to a new analysis.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial," wrote Pratik Mehta of the department of public health at the University of California, Berkeley, and Dr. Rebecca Smith-Bindman, who is the director of the radiology outcomes research lab at the University of California, San Francisco. "If individuals feel vulnerable and are worried about the scans, they might reconsider flying altogether since most of the small but real radiation risk they will receive will come from the flight and not from the exceedingly small exposures from scans."

The researchers estimated the cancer risk associated with exposure to radiation from a backscatter x-ray scan for a very large number of travelers, for a smaller group of more frequent travelers, and for 5-year-old girls – because children are more vulnerable to the effects of radiation exposure. The article was published online March 28 (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.105]) and will appear in the July 25 issue.

All Flyers

The researchers estimated that there would be an additional six cancers over the lifetime of 100 million passengers taking 750 million flights per year. However, "these cancers need to be considered in the context of the 40 million cancers that would develop in these individuals over the course of their lifetimes due to the high underlying cancer risk."

Frequent Flyers

The researchers assumed that among 1 million frequent flyers, who take 10 trips per week for a year for 6 hours each trip, there would be an additional four cancers from the backscatter scans. However, these cancers "need to be considered in the context of the 600 cancers that could occur from the radiation received from flying at high elevations and in context of the 400,000 cancers that would occur in these 1 million individuals over the course of their lifetimes," they wrote.

Five-Year-Old Girls

The researchers used a breast dose of 0.049 mcSv/backscatter scan and an increased risk of breast cancer of 9,140 cases/100,000 5-year-old girls exposed to a sievert of radiation. "We estimate that for every 2 million girls who travel one round trip per week, one additional breast cancer would occur from these scans over their lifetime. This increase of one cancer per 2 million young girls needs to be put into the context of the 250,000 breast cancers that will occur in these girls over the course of their lifetimes owing to the 12% lifetime incidence of breast cancer," the researchers pointed out.

Backscatter x-ray scanners expose an individual to 0.03 to 0.1 mcSv/scan, which amounts to the same dose as 3-9 minutes of exposure to naturally occurring radiation. Importantly, "naturally occurring radiation is higher at the altitudes of commercial air flights because of the greater proximity to the sun." Air travel is associated with an exposure of about 0.04 mcSv/per minute of flight time. In comparison, backscatter x-ray scans deliver radiation that is equivalent to 1-3 minutes of flight time.

Some question the usefulness of these estimates though, given the extremely small dose from a single scan. "It certainly is controversial," Dr. Richard L. Morin said in an interview. "A great number of scientists would say that while no one would disagree with the calculation itself, the problem is with the model." Dr. Morin is the chairman of the American College of Radiology’s safety committee and a professor of radiology at the Mayo Clinic in Jacksonville, Fla.

"There’s really no significant proof of an effect when you’re down at this level. ... In general, most scientific bodies would not make risk estimates of numbers this small because there’s lack of evidence," he said.

Still, the issue is concerning to the public because the Transportation Security Administration has stationed 486 scanners in 78 airports in the United States, according to Mr. Mehta and Dr. Smith-Bindman. Two types of scanners are in use at airports: Millimeter-wave scanners emit very low energy waves, while backscatter scanners use very low-dose x-rays. These machines are more commonly used in the United States.

"In contrast to x-rays used for medical imaging in which variation in transmission of x-rays through the body is used to generate an image, backscatter scanners detect radiation that reflects off of the person imaged ... with the backscatter technology, all of the energy of the scan is absorbed by the most superficial tissues of the body, such as the skin," the authors noted.

The safety of backscatter x-ray machines has been questioned because these scanners use ionizing radiation, which can cause damage to the body. The potential damage depends on the dose; at low doses, radiation causes biological damage that cells can quickly repair. At moderate doses, the cells can become cancerous or changed in ways that lead to other abnormalities such as birth defects. At even higher doses – such as those in radiation oncology – the cells cannot be replaced quickly enough, and serious health problems can occur.

While the doses of ionizing radiation emitted by backscatter machines are exceedingly low, it’s not clear whether the machines pose a health risk. The risk of cancer is an important consideration given that 750 million passengers board airplanes each year. "Even a small risk per person could potentially translate into a significant number of cancers," Mr. Mehta and Dr. Smith-Bindman wrote.

Estimating the cancer risk associated with backscatter x-ray machines is difficult. Estimations of this risk must be based on extrapolation of data from published studies that have demonstrated a cancer-radiation association but were based on much greater levels of radiation exposure. It is usually assumed that cancer risk is directly proportional to dose (linear dose-risk) and that every exposure carries some risk

Another difficulty is that exposure from backscatter machines is concentrated mostly in the skin, and there currently is no model for understanding the relationship between skin exposure and risk of skin cancer. However, "the backscatter x-rays will be concentrated in breast tissue, so the breast exposure from these scans can be used to accurately predict breast cancer risk," the investigators observed.

The researchers estimated backscatter x-ray exposure for three groups and made a few assumptions to calculate the risk. They assumed that all passengers undergo a full-body scan for each trip; that 100 million unique passengers will take 750 million flights per year; and that scan exposure is 0.1 mcSv. They extrapolated the estimates from the linear dose-risk relationship model. In addition, they assumed an increase of 0.08 cancers/Sv of exposure.

Concerns about the scanners remain "in part because the TSA does not permit independent assessment of the machines," the authors noted. It would be prudent for the TSA to permit additional testing to verify the safety of the devices, they added.

"In medicine, we try to balance risks and benefits of everything we do, and thus while the risks are indeed exceedingly small, the scanners should not be deployed unless they provide benefit – improved national security and safety – and consideration of these issues is outside the scope of our expertise." However, "if the scanners are not deemed efficacious, they should not be used," they wrote.

Radiologists tackled the question of potential long-term public health threats posed by backscatter x-ray scans in the April issue of Radiology.

David J. Brenner, Ph.D., argued in one commentary article that from a public health policy perspective, we should have some concerns about the long-term consequences of an extremely large number of people, regardless of how small the individual exposure risk is (Radiology 2011 [doi:10.1148/radiol.11102347]).

"The risks for any individual going through the x-ray backscatter scanners are exceedingly small. However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the x-ray scanners," Dr. Brenner said in a press release. Dr. Brenner is the director of the Center for Radiological Research at Columbia University, New York.

In a separate commentary article, David A. Schauer, Sc.D., argued that summing negligible average risks over large populations or time periods distorts the risk (Radiology 2011 [doi:10.1148/radiol.11102376]). "There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation," he said in a press release. Dr. Schauer is the executive director of the National Council on Radiation Protection and Measurement.

Dr. Schauer does advocate for strict regulatory control of backscatter scanners in order to ensure that benefits exceed cost or harm; that exposures are kept as low as reasonably achievable; and that individual doses are limited. In fact, the NCRP has recommended that these systems not exceed an effective dose of 0.1 mcSv of ionizing radiation per scan.

Both Dr. Brenner and Dr. Schauer agree that scanners using millimeter wave technology should be considered first options for screening passengers because there is no ionizing radiation risk.

Mr. Mehta and Dr. Smith-Bindman reported that they have no financial disclosures. Dr. Morin reported that he has no relevant financial disclosures.

The NRCP had a grant from the Food and Drug Administration for this commentary by Dr. Schauer. Dr. Schauer had no other relevant financial disclosures. Dr. Brenner had no relevant financial disclosures.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.

Individuals who have had a transient ischemic attack are twice more likely than are those in the general population to have a myocardial infarction, indicating that TIA might be a significant risk factor for MI, according to a population-based study that was published online in Stroke on March 24.

In addition, "in the population of patients with TIA we studied, having MI increased the risk of death by a factor of three. This supports the concept of careful primary prevention of CAD [coronary artery disease] in TIA patients, even in the absence of symptoms. It also suggests that screening for CAD in at least some TIA patients may be reasonable," wrote Dr. Joseph D. Burns and his coinvestigators at the Mayo Clinic in Rochester, Minn. (Stroke 2011;42 [doi: 10.1161/STROKEAHA.110.593723]).

The researchers studied a community-based cohort of patients with incident TIA that was identified retrospectively through the Rochester Epidemiology Project Medical Records Linkage System, which holds medical record data for these individuals for all care provided, as well as and autopsy or death certificate information.

The investigators identified a cohort of Rochester residents who had incident TIA during 1985-1994 and a cohort of Olmsted County (Minn.) residents who had incident MI during 1979-2006.

A total of 456 Rochester residents had an incident TIA in 1985-1994. Of these, 15% (68) had a history of MI before TIA and were excluded from the analysis. Therefore the study results pertain to the 388 remaining patients.

On average, patients were 71 years old at the time of TIA and 41% of the patients were male. In terms of cardiovascular risk factors, 62% had hypertension, 11% had diabetes mellitus, and 55% were current or former smokers. Based on TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes, 19% of the TIAs were attributable to large artery atherosclerosis, 13% were cardioembolic, 6% were lacunar, and 5% were attributable to other causes. Importantly, a single etiology could not be clearly established for 57% of the TIAs.

Median follow-up for patients who had a TIA was 10 years. Of these, 44 patients had an MI after the TIA – an average annual incidence of MI after TIA of 0.95%. Median time from index TIA to index MI was 4.6 years. The risk of MI after TIA remained essentially constant over time, based on a survival analysis.

The age-, sex-, and period-specific relative risk for incident MI in patients who had TIA – when compared with that of the general population – was 2.09. Interestingly, this elevated risk was most pronounced in TIA patients younger than 60 years old. For those younger than 60 years, that relative risk was 15.1, when compared with the general population. In comparison, for patients 60 years and older, the age-, sex-, and period-specific relative risk for MI aggregated over three age groups (60-69 years, 70-79 years, and 80 years or older) was 1.93, when compared with the general population.

Using univariate proportional hazards analysis, the researchers found that increasing age and hypertension were associated with an increased risk of incident MI after TIA. Notably, the use of lipid-lowering agents at the time of the TIA showed a trend toward association with an increased risk of MI after TIA.

However, on multivariable analysis, the researchers identified increasing age (hazard ratio, 1.51/10 years), male sex (HR, 2.19), and the use of lipid-lowering therapy at the time of TIA (HR, 3.10) to be independent risk factors for MI after TIA. TIA etiology was not a significant predictor, though this analysis was limited by the fact that a single etiology could not be identified in many patients.

"Our findings regarding the risk conferred by age and sex are consistent with the current understanding of CAD risk factors and pathogenesis," the investigators wrote. "Although hypertension is an important risk factor for CAD, its role as a risk factor for MI after TIA is unclear from our data." Effective treatment of hypertension could have obscured a difference in MI risk, they suggested.

On univariate analysis, the researchers found that patients who had an MI after a TIA were approximately three times more likely to die during follow-up than were those who did not have MI after TIA (HR, 3.19). Even when researchers adjusted for other factors found to be associated with mortality in this group, MI remained a significant and substantial independent predictor of death after TIA.

The authors acknowledged that the study has limitations. "Racial and ethnic differences exist in the epidemiology of CAD and ischemic cerebrovascular disease. Because the population of Rochester is predominantly white, our findings might not be applicable to other racial and ethnic groups."

There was also insufficient data available to assess the effects of lipid and cholesterol disorders – key CAD risk factors – on the risk of MI after TIA. Also, "the cohort size number of events may limit power to detect risk factors for MI after TIA."

The study was supported by the Mayo Clinic. The investigators did not report any relevant financial relationships. Dr. Burns is now affiliated with the departments of neurology and neurosurgery at Boston University.