title: Association between sleep and physical function in older men: the osteoporotic fractures in men sleep study.
abstract: OBJECTIVE
  To determine whether sleep quality is associated with physical function in older men.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Six U.S. centers.
  
  
  METHODS
  Two thousand eight hundred sixty-two community-dwelling men.
  
  
  METHODS
  Total hours of nighttime sleep (TST), wake after sleep onset (WASO), sleep latency (SL), and sleep efficiency (SE) measured using actigraphy; sleep stage distribution, respiratory disturbance index (RDI), and hypoxia measured using polysomnography; measures of physical function: grip strength, walking speed, chair stand, and narrow walk.
  
  
  RESULTS
  In age-adjusted models, <6 or >8 hours TST, SE less than 80%, WASO of 90 minutes or longer, RDI of 30 or greater, and hypoxia were associated with poorer physical function. (Mean grip strength was 2.9% lower and mean walking speed was 4.3% lower in men with WASO >or=90 minutes than men with WASO <90 minutes.) After adjusting for potential covariates, differences in grip strength and walking speed remained significantly associated with WASO of 90 minutes or longer, SE less than 80%, and hypoxia but not with TST or RDI of 30 or greater.
  
  
  CONCLUSIONS
  Greater sleep fragmentation and hypoxia are associated with poorer physical function in older men.
authors.affiliation: Department of Medicine, University of California at San Diego, La Jolla, California, USA. tldam@ucsd.edu
authors.forename: Thuy-Tien L
authors.initials: TT
authors.lastname: Dam
authors.forename: Susan
authors.initials: S
authors.lastname: Ewing
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Kristine
authors.initials: K
authors.lastname: Ensrud
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
authors.forename: Katie
authors.initials: K
authors.lastname: Stone