An observational study of more than 1,000 patients at the Yale Center for Sleep Medicine found that obstructive sleep apnea significantly increases the risk of stroke or death from any cause, and that the risk is linked to sleep apnea severity.

The researchers found the increased risk to be independent of other factors, including hypertension. Participants were over age 50 without a history of heart attack or stroke at the start of the study. They were followed for an average of just under 3.5 years. The report cites support from the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, the Yale Center for Sleep Medicine, and the Veterans Affairs Health Services Research and Development Service, states a NIH release.

Untreated obstructive sleep apnea has been shown to increase the chance of cardiovascular disease and associated risk factors including high blood pressure, heart attack, stroke, and diabetes as well as injuries or deaths from work-related accidents and vehicular crashes. NHLBI is currently supporting several large studies which follow participants over longer periods of time to confirm the longitudinal relationship between sleep apnea and stroke and associated risk factors.

NHLBI is a component of the National Institutes of Health (NIH) of the US Department of Health and Human Services.