Risk factors for obstructive sleep apnea (OSA) and the subsequent development of associated problems with this condition, such as cardiovascular complications have been suspected to vary by sex, but until recently, whether the effects of OSA on heart disease is similar for men and women had not been clearly established. Researchers have discovered that OSA is more dangerous for women than for men in their study.

Published in Circulation in October, the results of the research found that gender does play a role between OSA and cardio vascular disease, and that in women, sleep apnea was associated with higher blood levels of troponin (hs-TnT), a biomarker of heart disorders of which the most important is myocardial infarction (heart attack). Also, increased levels of troponin indicate cardiac muscle cell death because the enzyme is released into the blood upon injury to the heart.

“The finding that sleep apnea is associated with evidence of early heart injury and an elevation in long term risk of heart failure, coronary heart disease, enlargement of the heart muscle, and death in women highlights the importance of sleep apnea screening and treatment for women, a group who often are not routinely screened for sleep apnea,” says co-author Susan Redline, MD, MPH, and associate clinical director at the Division of Sleep and Circadian Disorders at BWH.

The study examined post-menopausal women, who are at a greater risk for sleep apnea and heart disease. The study concluded that older women may be at relatively greater risk of sleep apnea related heart disease compared to men.

The study took participants of an average age of approximately 63 years, of whom 23% were men and 10% women having undiagnosed moderate to severe OSA. Over a 14 year follow up, 46% of men and 32% of women experienced a significant adverse cardiac event, death, or had an enlarged heart. Women with moderate to severe OSA were more than 30% likely to experience these adverse heart problems compared to women without OSA. This relationship was not statistically significant in men, suggesting that factors such as age, obesity, hypertension, and diabetes explained most of the observed heart disease risk in the men studied.

“We hope these results focus attention on the importance of sleep apnea in women, who historically are under-diagnosed in this area,” Redline says. Another aspect of this study that we should pay attention to is that even among women with obstructive sleep apnea who don’t get heart disease or attacks, the condition is associated with changes in the heart, which may lead to worse ramifications.