Daytime sleepiness predicts death in the elderly

Excessive daytime sleepiness is an independent risk factor for cardiovascular-related mortality as well as mortality from other causes in elderly individuals, French researchers report.

"Complaints of excessive daytime sleepiness are very frequent in the elderly, but there have been few studies relating daytime sleepiness and mortality in the elderly and those results were mixed," lead investigator Dr. Jean-Philippe Empana, from Hopital Paul Brousse, Villejuif, said in a statement.

To this end, the investigators conducted a population-based study in France, called the Three City Study, which included 9,294 subjects, 65 years of age or older, who were recruited between 1999 and 2001. At enrollment, 8,269 of the subjects completed questionnaires regarding excessive daytime sleepiness, sleep complaints, and medication use for anxiety or sleep.

Overall, 18.7 percent of subjects reported feeling sleepy on a regular basis or frequently during the day, the researchers note in their study, soon to be published in the journal Stroke.

During 6 years of follow-up, 762 subjects died, including 196 from cardiovascular disease and 260 from cancer. After adjusting for age, gender, body mass index, previous cardiovascular disease, and other possible contributing factors, excessive daytime sleepiness increased the risk of death by 33 percent.

Accounting for sleep medication use and for depressive symptoms only slightly weakened the association between excessive daytime sleepiness and mortality. Moreover, excessive daytime sleepiness could not be predicted by loud snoring.

Further analysis showed that excessive daytime sleepiness increased the odds of cardiovascular mortality by 49 percent, but had no statistically significant effect on the risk of death due to cancer (12 percent).

"These data may have clinical implications adding to the body of evidence that excessive daytime sleepiness is not a benign but rather an important risk marker of death in community-dwelling elderly," Empana said.

SOURCE: Stroke, April 2009.