A new study found that people with untreated obstructive sleep apnea had an increased risk of stroke. This effect was stronger in men than in women.
The study involved 5,422 people who were 40 years of age and older. They had no history of stroke and had never been treated for sleep apnea. Each person’s sleep was monitored during a home sleep test sometime between 1995 and 1998.
Participants were followed for an average of almost nine years. During this study period 193 of them had a stroke.
Results show that the risk of stroke in men rose with the severity of sleep apnea. Men with moderate to severe sleep apnea were nearly three times more likely to have a stroke than men without sleep apnea or with mild sleep apnea.
"Our findings provide compelling evidence that obstructive sleep apnea is a risk factor for stroke, especially in men," lead author Dr. Susan Redline said in a news release. "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."
In women an increased risk of stroke was found only with more severe levels of OSA. The authors noted that men are more likely than women to develop sleep apnea at younger ages. So the more prominent stroke risk in men might be related to having untreated sleep apnea for longer periods of time.
A stroke is a “brain attack” that occurs when blood flow to the brain is interrupted. It can result from either a blood clot that blocks an artery or from a broken blood vessel. Stroke is the third-leading cause of death in the U.S.
Last year a study reported that the effects of a stroke may be more severe in people who have OSA. Another study suggested that blood flow impairments might explain the link between sleep apnea and stroke.
The good news is that sleep apnea can be treated. CPAP therapy is the treatment of choice for all severity levels of OSA.
“The time is right for researchers to study whether treating sleep apnea could prevent or delay stroke in some individuals,” said Dr. Susan B. Shurin. She is the acting director of the National Heart, Lung, and Blood Institute. The NHLBI funded the study.
Read more about obstructive sleep apnea and CPAP therapy. Get help for sleep apnea at an AASM-accredited sleep center near you.