title: Sleep-wake disturbances in sedentary community-dwelling elderly adults with functional limitations.
abstract: OBJECTIVE
  To evaluate sleep-wake disturbances in sedentary community-dwelling elderly adults with functional limitations.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Lifestyle Interventions and Independence in Elder (LIFE) Study.
  
  
  METHODS
  Community-dwelling persons (mean age 78.9) who spent fewer than 20 min/wk in the previous month engaged in regular physical activity and fewer than 125 min/wk of moderate physical activity, and had a Short Physical Performance Battery (SPPB) score of <10 (N = 1,635).
  
  
  METHODS
  Mobility was evaluated according to 400-m walk time (slow gait speed defined as <0.8 m/s) and SPPB score (≤ 7 defined moderate to severe mobility impairment). Physical inactivity was defined according to sedentary time, as a percentage of accelerometry wear time with activity of <100 counts/min; participants in the top quartile of sedentary time were classified as having a high sedentary time. Sleep-wake disturbances were evaluated using the Insomnia Severity Index (ISI) (range 0-28; ≥ 8 defined insomnia), Epworth Sleepiness Scale (ESS) (range 0-24; ≥ 10 defined daytime drowsiness), Pittsburgh Sleep Quality Index (PSQI) (range 0-21; >5 defined poor sleep quality), and Berlin Questionnaire (high risk of sleep apnea).
  
  
  RESULTS
  Prevalence rates were 43.5% for slow gait speed and 44.7% for moderate to severe mobility impairment, with 77.0% of accelerometry wear time spent as sedentary time. Prevalence rates were 33.0% for insomnia, 18.1% for daytime drowsiness, 47.8% for poor sleep quality, and 32.9% for high risk of sleep apnea. Participants with insomnia had a mean ISI score of 12.1, those with daytime drowsiness had a mean ESS score of 12.5, and those with poor sleep quality had a mean PSQI score of 9.2. In adjusted models, measures of mobility and physical inactivity were generally not associated with sleep-wake disturbances, using continuous or categorical variables.
  
  
  CONCLUSIONS
  In a large sample of sedentary community-dwelling elderly adults with functional limitations, sleep-wake disturbances were prevalent but only mildly severe and were generally not associated with mobility impairment or physical inactivity.
authors.affiliation: Clinical Epidemiology Research Center, Veterans Affairs Connecticut, West Haven, Connecticut; Department of Medicine, School of Medicine, Yale University, New Haven, Connecticut.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Vaz Fragoso
authors.forename: Michael E
authors.initials: ME
authors.lastname: Miller
authors.forename: Roger A
authors.initials: RA
authors.lastname: Fielding
authors.forename: Abby C
authors.initials: AC
authors.lastname: King
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Mary M
authors.initials: MM
authors.lastname: McDermott
authors.forename: Valerie
authors.initials: V
authors.lastname: Myers
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Marco
authors.initials: M
authors.lastname: Pahor
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gill
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D012111:Residence Characteristics; D057185:Sedentary Behavior; D020178:Sleep Disorders, Circadian Rhythm / Q000209:etiology*
keywords: mobility impairment; physical inactivity; sleep-wake disturbances