Researchers followed the participants for an average of about nine years. They report that during the study, 193 participants had a stroke 85 men (of 2,462 men enrolled) and 108 women (out of 2,960 enrolled).
After adjusting for several cardiovascular risk factors, the researchers found that the effect of sleep apnea on stroke risk was stronger in men than in women. In men, a progressive increase in stroke risk was observed as sleep apnea severity increased from mild levels to moderate to severe levels. In women, however, the increased risk of stroke was significant only with severe levels of sleep apnea.
The researchers suggest that the differences between men and women might be because men are more likely to develop sleep apnea at younger ages. Therefore, they tend to have untreated sleep apnea for longer periods of time than women. "It's possible that the stroke risk is related to cumulative effects of sleep apnea adversely influencing health over many years," said Susan Redline, M.D., MPH, professor of medicine, pediatrics, and epidemiology and biostatistics, at Case Western Reserve University in Cleveland and lead author of the paper.
"Our findings provide compelling evidence that obstructive sleep apnea is a risk factor for stroke, especially in men," noted Redline. "Overall, the increased risk of stroke in men with sleep apnea is comparable to adding 10 years to a man's age. Importantly, we found that increased stroke risk in men occurs even with relatively mild levels of sleep apnea."
"Research on the effects of sleep apnea not only increases our understanding of how
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NIH/National Heart, Lung and Blood Institute