Linked with Depression and Diabetes
The likelihood of being excessively sleepy during the day is more than three times higher among people who report being treated for depression and about twice as high for those with diabetes, according to Edward Bixler and his coworkers at Pennsylvania State University in Hershey, Penn.
Smoking is also linked with daytime sleepiness. The researchers suggest smokers might be using the stimulant effect of nicotine to self-treat their drowsiness.
Bixler's team studied a random sample of more than 16,000 men and women ranging in age from 20 to 100 years, nearly nine per cent of whom reported excessive daytime sleepiness. A random sample of more than 1,700 people received further evaluation in a sleep laboratory.
Depression was the most significant risk factor for excessive daytime sleepiness, followed by body mass index (a measure of obesity), age, typical sleep duration, diabetes, smoking and finally sleep apnea, a condition in which sleep is interrupted by repeated pauses in breathing.
Excessive daytime sleepiness is more common in people younger than 30, the
authors noted, "suggesting the presence of unmet sleep needs and depression,"
and in those older than 75, "suggesting increasing medical illness and health