title: Sleep duration associated with mortality in elderly, but not middle-aged, adults in a large US sample.
abstract: OBJECTIVE
  To explore age differences in the relationship between sleep duration and mortality by conducting analyses stratified by age. Both short and long sleep durations have been found to be associated with mortality. Short sleep duration is associated with negative health outcomes, but there is little evidence that long sleep duration has adverse health effects. No epidemiologic studies have published multivariate analyses stratified by age, even though life expectancy is 75 years and the majority of deaths occur in the elderly.
  
  
  METHODS
  Multivariate longitudinal analyses of the first National Health and Nutrition Examination Survey using Cox proportional hazards models.
  
  
  METHODS
  Probability sample (n = 9789) of the civilian noninstitutionalized population of the United States between 1982 and 1992.
  
  
  METHODS
  Subjects aged 32 to 86 years.
  
  
  RESULTS
  In multivariate analyses controlling for many covariates, no relationship was found in middle-aged subjects between short sleep of 5 hours or less and mortality (hazards ratio [HR] = 0.67, 95% confidence interval [CI] 0.43-1.05) or long sleep of 9 hours or more and mortality (HR = 1.04, 95% CI 0.66-1.65). A U-shaped relationship was found only in elderly subjects, with both short sleep duration (HR = 1.27, 95% CI 1.06-1.53) and long sleep duration (HR = 1.36, 95% CI 1.15-1.60) having significantly higher HRs.
  
  
  CONCLUSIONS
  The relationship between sleep duration and mortality is largely influenced by deaths in elderly subjects and by the measurement of sleep durations closely before death. Long sleep duration is unlikely to contribute toward mortality but, rather, is a consequence of medical conditions and age-related sleep changes.
authors: Columbia University, College of Physicians and Surgeons, Department of Psychiatry, Division of Medical Genetics, New York, NY 10032, USA. jeg64@columbia.edu
authors: James E
authors: JE
authors: Gangwisch
authors: Steven B
authors: SB
authors: Heymsfield
authors: Bernadette
authors: B
authors: Boden-Albala
authors: Ruud M
authors: RM
authors: Buijs
authors: Felix
authors: F
authors: Kreier
authors: Mark G
authors: MG
authors: Opler
authors: Thomas G
authors: TG
authors: Pickering
authors: Andrew G
authors: AG
authors: Rundle
authors: Gary K
authors: GK
authors: Zammit
authors: Dolores
authors: D
authors: Malaspina
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015897:Comorbidity; D006970:Disorders of Excessive Somnolence / Q000401:mortality*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012307:Risk Factors; D012494:Sampling Studies; D012892:Sleep Deprivation / Q000401:mortality*; D012893:Sleep Wake Disorders / Q000401:mortality*; D014481:United States