Seems an odd result

Top risk of stroke for normal-weight adults: Getting under 6 hours of sleep

The participants had no history of stroke, transient ischemic attack, stroke symptoms or high risk for OSA at the start of the study, being presented today at SLEEP 2012. Researchers from the University of Alabama at Birmingham recorded the first stroke symptoms, along with demographic information, stroke risk factors, depression symptoms and various health behaviors.

After adjusting for body-mass index (BMI), they found a strong association with daily sleep periods of less than six hours and a greater incidence of stroke symptoms for middle-age to older adults, even beyond other risk factors. The study found no association between short sleep periods and stroke symptoms among overweight and obese participants.

"In employed middle-aged to older adults, relatively free of major risk factors for stroke such as obesity and sleep-disordered breathing, short sleep duration may exact its own negative influence on stroke development," said lead author Megan Ruiter, PhD. "We speculate that short sleep duration is a precursor to other traditional stroke risk factors, and once these traditional stroke risk factors are present, then perhaps they become stronger risk factors than sleep duration alone."