Excessive daytime drowsiness in older adults may predict a significantly increased risk of stroke, said researchers reporting data on Thursday at the International Stroke Conference in New Orleans.

　　Most people have, from time to time, unintentionally dozed off on the couch watching television or reading a book or even stopped in traffic while driving. But persistent drowsiness during the day usually signals a chronic sleep deficit, and bigger problems. The new study found that people who suffered from "significant dozing" — those who almost always fell asleep involuntarily during the day — were 4.5 times more likely to have a stroke than people in the "no dozing" group. The association between sleepiness and stroke was: the sleepier the person, the higher the risk of stroke.