Risk of Napping: Excessive Daytime Sleepiness and Mortality in an Older Community Population
The research on which this publication was based was performed pursuant to contract number N01-AG-1–2102 with the National Institute on Aging, in support of the Established Populations for Epidemiologic Studies of the Elderly (Duke). Presented at the Annual Scientific Meeting of the American Geriatrics Society, Los Angeles, California, May 1994.
Abstract
OBJECTIVE: To describe the demographic and health-related factors related to excessive daytime sleepiness. To estimate the risk of mortality associated with excessive daytime sleepiness independent of nighttime sleep problems and other factors that limit survival.
DESIGN: Four-year prospective cohort study with annual interviews.
SETTING: One urban and four rural counties in north-central North Carolina.
PARTICIPANTS: Adults 65 years and older (n = 3962) living in the community.
MAIN OUTCOME MEASURES: Excessive daytime sleepiness was measured as, “How often do you get so sleepy during the day or evening that you have to take a nap?” Mortality was based on continuous surveillance of the population by field investigators and abstraction of death certificates.
RESULTS: Point prevalence of excessive daytime sleepiness in this population was 25.2%. Frequent daytime nappers were more likely than infrequent nappers to report nighttime sleep complaints and were more likely to be male and urban-dwellers, to report more depressive symptoms, more limited physical activity, and more functional impairment, and were more likely to be overweight. Of the frequent nappers, 23.9% died, compared with 15.4% of infrequent nappers. In an adjusted Cox proportional hazard model, the 4-year mortality rate was accelerated 1.73 times among older people who nap most of the time and make two or more errors on a cognitive status examination.
CONCLUSION: Excessive napping is associated with impaired sleep hygiene as well as with a broad range of activity-related health deficits among community-dwelling older adults. Frequent napping was associated with impaired sleep hygiene, male gender, urban-dwelling, depressive symptoms, physical activity deficits, functional impairment, and excess weight. Mortality risk was elevated selectively among the most cognitively impaired subjects.
