News Story - Too much sleep tied to stroke risk in postmenopausalwomen

Too much sleep tied to stroke risk in older women
By Will Dunham
Thu Jul 17, 5:18 PM ET

Regularly getting nine hours or more of sleep per night may increase
the risk of stroke in postmenopausal women, according to a study
published on Thursday.

Only 5 percent of the 93,000 women in the study, who were 50 to 79
years old and from 40 locations around the United States, reported
getting nine hours or more of sleep nightly.

But they had a 60 percent to 70 percent higher risk of stroke compared
to women getting seven hours of sleep per night, the most common sleep
duration, the researchers wrote in the American Heart Association
journal Stroke.

The researchers statistically accounted for known risk factors for
stroke and still found the increased risk in the longer-sleeping
women.

"Whether it's because of sleep apnea or because of restless sleep or
because of any number of things, we don't know," Sylvia Wassertheil-
Smoller of Albert Einstein College of Medicine in New York, one of the
researchers, said in a telephone interview.

"The study definitely does not say that for women who sleep longer, if
they decrease their hours of sleep they'll be better off," Wassertheil-
Smoller, an epidemiologist, added.

The researchers said it is unclear whether the findings would apply to
men and younger women.

The study, which ran from 1994 to 2005, also saw an increased stroke
risk among women who got no more than six hours of sleep a night.

But this was a much smaller effect. The researchers said there was a
14-percent higher risk in this group compared to those getting seven
hours of sleep.

Wassertheil-Smoller noted there are known bad physiological effects
from sleep deprivation that might play a role.

Previous research into sleep duration and risk of stroke or coronary
artery disease provided inconsistent results.

The study found that in this group of postmenopausal women, 8 percent
reported getting five hours or less sleep a night, 27 percent reported
getting six hours, 38 percent reported getting seven hours, and 23
percent reported getting eight hours.

Some 4 percent reported getting nine hours and 1 percent reported
getting 10 hours or more.