Sleep apnea, a condition where people stop breathing repeatedly while asleep, increases the risk of stroke and death, according to a study from Yale School of Medicine published November 10 in the New England Journal of Medicine.
Stroke is the third leading cause of death in the United States and the leading cause of long-term disability. Some of the known risk factors for stroke include high blood pressure, smoking, diabetes, and high cholesterol. This study discovered sleep apnea as a new risk factor for stroke.
The lead author of the study, H. Klar Yaggi, M.D., assistant professor of medicine in the section of pulmonary critical care medicine, said, “Our study shows that sleep apnea doubles the risk for the development of stroke and death, and severe sleep apnea more than triples the risk. We found that this risk was independent of other risk factors, including high blood pressure.”
Sleep apnea affects as many as one in five adults in the United States. Common symptoms include daytime sleepiness, loud snoring, and pauses in breathing while asleep — often noticed by the bed partner. Being overweight or obese significantly increases risk for sleep apnea, and men are at more risk than women.
Previous studies showed many stroke patients had sleep apnea, but it was not clear whether sleep apnea was the cause or the result of stroke.
The study included 1,022 patients from the Yale Center for Sleep Medicine, of whom 697 had sleep apnea. Stroke or death occurred in 72 patients with sleep apnea, compared to16 in the group without sleep apnea.
“Sleep apnea is a common and serious problem, but it is also highly treatable,” Yaggi said. “If you or someone you know has symptoms of sleep apnea, it is important to discuss this with a doctor.”
The study was supported by a National Institutes of Health Research Service Award Institutional Research Training Grant, Veterans Affairs Health Services Research and Development Career Development Award, and the Yale Center for Sleep Medicine. Co-authors include senior author, Vahid Mohsenin, M.D., John Concato, M.D., Walter Kernan, M.D., Judith Lichtman and Lawrence Brass, M.D., all of Yale.
New England Journal of Medicine: November 10, 2005.
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