title: Nocturnal activity and immobility across aging (50-98 years) in healthy persons.
abstract: OBJECTIVE
  To measure the influence of age on measures of nocturnal activity and immobility in 100 healthy subjects aged 50 to 98 years.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Urban population in Leiden. Recordings were performed at home while the subjects maintained their habitual 24-hour pattern of activities.
  
  
  METHODS
  100 subjects without a history of major medical disorders and a normal neurological examination and performance-oriented assessment of gait (Tinetti).
  
  
  METHODS
  Motor activity was recorded during six successive nights with a wrist-worn activity monitor. The occurrence of supra-threshold motor activity was recorded over 15-second epochs. A questionnaire was used to evaluate sleep habits and the occurrence of sleep disturbances. Four mean measures reflecting activity or immobility during the nocturnal period were calculated for each subject.
  
  
  RESULTS
  Only one out of four measures, (ie, the nocturnal proportion of time with movement, increased with age for females. For males, no age effects emerged. The mean duration of nocturnal immobility periods was higher in females than in males. Also, for females, the use of hypnotics increased with successive decades. Sex and the use of hypnotics were significantly related to the mean duration of immobility periods.
  
  
  CONCLUSIONS
  If care is taken not to confound aging with illness, measures of nocturnal activity and immobility reveal only marginal effects of aging.
authors.affiliation: Dept. of Neurology, Academic Hospital, Leiden, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: van Hilten
authors.forename: H A
authors.initials: HA
authors.lastname: Middelkoop
authors.forename: E A
authors.initials: EA
authors.lastname: Braat
authors.forename: E A
authors.initials: EA
authors.lastname: van der Velde
authors.forename: G A
authors.initials: GA
authors.lastname: Kerkhof
authors.forename: G J
authors.initials: GJ
authors.lastname: Ligthart
authors.forename: A
authors.initials: A
authors.lastname: Wauquier
authors.forename: H A
authors.initials: HA
authors.lastname: Kamphuisen
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D000704:Analysis of Variance; D002940:Circadian Rhythm; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D004651:Employment; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D017286:Polysomnography; D012737:Sex Factors; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013997:Time Factors; D014505:Urban Population
chemical_list: D006993:Hypnotics and Sedatives