title: Napping and 24-hour sleep/wake patterns in healthy elderly and young adults.
abstract: OBJECTIVE
  To examine differences between healthy elderly and young adults in daytime napping, nocturnal sleep, and 24-hour sleep/wake patterns. A second objective was to determine whether elderly subjects with more and less frequent naps differed in their clinical features or nocturnal sleep.
  
  
  METHODS
  Survey by sleep/wake logs and polysomnography. Comparison by age.
  
  
  METHODS
  Sleep/wake logs were completed in the subjects' homes. Polysomnographic studies were conducted on an outpatient basis in a sleep and chronobiology research laboratory.
  
  
  METHODS
  Convenience samples of forty-five healthy subjects over 78 years of age (21M, 24F) and 33 healthy adults between 20 and 30 years of age (20M, 13F).
  
  
  METHODS
  Using self-reports, we estimated the frequency and timing of daytime naps; timing, duration, and quality of nocturnal sleep; and 24-hour patterns of sleep and wakefulness. Also polysomnographic sleep measures.
  
  
  RESULTS
  Compared to young adults, elderly subjects reported a greater mean number of daytime naps (P = .004), shorter nocturnal sleep with more wakefulness and earlier sleep hours (P less than .003 for each), and a trend for a shorter 24-hour sleep fraction. Among the elderly, more-frequent and less-frequent nappers did not differ in clinical ratings, self-report sleep measures, or polysomnographic measures. There was a trend for more sleep-disordered breathing and periodic limb movements in more frequent nappers.
  
  
  CONCLUSIONS
  These findings are consistent with an age-related decrease in amplitude of the circadian sleep propensity rhythm, or with the expression of a semi-circadian (12-hour) sleepiness rhythm. However, we cannot exclude the additional possibility that napping results from lifestyle factors and nocturnal sleep pathologies in a subset of the elderly.
authors.forename: D J
authors.initials: DJ
authors.lastname: Buysse
authors.forename: K E
authors.initials: KE
authors.lastname: Browman
authors.forename: T H
authors.initials: TH
authors.lastname: Monk
authors.forename: C F
authors.initials: CF
authors.lastname: Reynolds
authors.forename: A L
authors.initials: AL
authors.lastname: Fasiczka
authors.forename: D J
authors.initials: DJ
authors.lastname: Kupfer
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002940:Circadian Rhythm; D004358:Drug Therapy / Q000706:statistics & numerical data; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008499:Medical Records; D008991:Monitoring, Physiologic; D012737:Sex Factors; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology