Too much sleep increases the risk of stroke in older women

Jul 21 2008

Researchers in the United States have found that for older women too much or too little sleep increases their risk of a stroke.

According to a new study by a team at the Albert Einstein College of Medicine in New York City, the habitual sleep patterns in postmenopausal women could be significant in predicting their risk of an ischemic stroke.

The researchers studied 93,676 postmenopausal women and found that those who regularly slept nine hours or more were 70 percent more likely to have an ischemic stroke, compared with women who slept seven hours a night.

They also found that women who slept six hours or less per night had a 14 percent higher risk of stroke compared to those who slept seven hours a night.

The most common type of stroke is an ischemic stroke which is caused by a blockage in an artery supplying blood to the brain.

The researchers however warn that their findings do not suggest that if women reduce the amount of time they sleep from over nine hours, that they would lower their stroke risk.

The researchers say the increased risk of stroke was only found in postmenopausal women ages 50 to 79 and is not applicable to younger men and women.

Lead author Dr. Jiu-Chiuan Chen says even when other known risk factors were accounted for, sleeping nine hours or more is strongly associated with increased risk of ischemic stroke.

For the research Chen and his colleagues used data from the ten year multi-ethnic Women’s Health Initiative Observational Study; at the time of their enrollment at 40 U.S. clinical centers the women were aged between 50 to 79 years.

The team also found that sleeping longer was associated with being retired or unemployed; smoking, being physically inactive or having cardiovascular disease, diabetes, hypertension, high cholesterol or depression.

According to the U.S. Centers for Disease Control and Prevention (CDC) most adults should get seven to 9 hours of sleep each night, children ages 5 through 12 should get 9 to 11 hours, and adolescents need 8.5 to 9.5.

The research is published in Stroke, a Journal of the American Heart Association.