Resumen de Sleep-Wake Disturbances in Sedentary Community-Dwelling Elderly Adults with Functional Limitations

Carlos A. Vaz Fragoso, Michael E. Miller, Roger A. Fielding, Abby C. King, Stephen B. Kritchevsky, Mary M. McDermott, Valerie H. Myers, Anne B. Newman, Marco Pahor, Thomas M. Gill

• Objectives: To evaluate sleep�wake disturbances in sedentary community-dwelling elderly adults with functional limitations.

  Design: Cross-sectional.

  Setting: Lifestyle Interventions and Independence in Elder (LIFE) Study.

  Participants: 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).

  Measurements: 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.

  Conclusion: 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.