title: Risk of napping: excessive daytime sleepiness and mortality in an older community population.
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 nightime sleep problems and other factors that limit survival.
  
  
  METHODS
  Four-year prospective cohort study with annual interviews.
  
  
  METHODS
  One urban and four rural counties in north-central North Carolina.
  
  
  METHODS
  Adults 65 years and older (n = 3962) living in the community.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Hays
authors.forename: D G
authors.initials: DG
authors.lastname: Blazer
authors.forename: D J
authors.initials: DJ
authors.lastname: Foley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D006970:Disorders of Excessive Somnolence / Q000209:etiology* / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D009657:North Carolina / Q000453:epidemiology; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012423:Rural Health; D016019:Survival Analysis; D014504:Urban Health