title: Poor sleep is associated with poorer physical performance and greater functional limitations in older women.
abstract: OBJECTIVE
  This study examined the association between disturbed sleep and poorer daytime function in older women.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  2,889 women, mean age 83.5 years, participating in the 2002-2004 examination of the Study of Osteoporotic Fractures.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Participants wore actigraphs for an average +/- SD of 4.1 +/- 0.83 24-hour periods. Actigraphy measured sleep variables were total sleep time and hours awake after sleep onset during the night and daytime napping behavior. Neuromuscular performance measurements included gait speed, chair stands, and grip strength. Functional limitations were assessed as self-reported difficulty with one or more of 6 instrumental activities of daily living (IADL). In fully adjusted, multivariable models, women who slept <6 hours per night walked 3.5% slower than those who slept 6.0-6.8 hours. Those who slept > or =7.5 hours took 4.1% longer to complete 5 chair stands than those who slept 6.8-7.5 hours. With higher wake after sleep onset (> or =1.6 hours compared to <0.7 hours) gait speed was 9.1% slower; it took 7.6% longer to complete 5 chair stands, and odds of functional limitation were 1.8 (95% CI: 1.4, 2.4) higher. Women with 1.0-1.8 hours of daytime sleep had higher odds (1.4 [95% CI: 1.1, 1.8]) of a functional limitation than those with <0.5 hours. Sleep variables did not appear to be associated with grip strength.
  
  
  CONCLUSIONS
  Objectively measured poorer sleep was associated with worse physical function. Future research is needed to identify the underlying mechanisms for the association between poor sleep and functional decline.
authors.affiliation: Department of Epidemiology, University ofPittsburgh, Pittsburgh, PA, USA.
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Goldman
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Terri
authors.initials: T
authors.lastname: Blackwell
authors.forename: Susan K
authors.initials: SK
authors.lastname: Ewing
authors.forename: Robert
authors.initials: R
authors.lastname: Boudreau
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Martica
authors.initials: M
authors.lastname: Hall
authors.forename: Karen A
authors.initials: KA
authors.lastname: Matthews
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D001143:Arousal; D015984:Causality; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology; D015331:Cohort Studies; D015897:Comorbidity; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D017286:Polysomnography; D011596:Psychomotor Disorders / Q000453:epidemiology*; D012044:Regression Analysis; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D016387:Women's Health