title: Association of sleep characteristics and cognition in older community-dwelling men: the MrOS sleep study.
abstract: OBJECTIVE
  To examine the association of objectively and subjectively measured sleep characteristics with cognition in older men.
  
  
  METHODS
  A population-based cross-sectional study.
  
  
  METHODS
  6 centers in the United States.
  
  
  METHODS
  3,132 community-dwelling older men (mean age 76.4 ± 5.6 years).
  
  
  METHODS
  None.
  
  
  RESULTS
  Objectively measured sleep predictors from wrist actigraphy were total sleep time (TST), sleep efficiency (SE), and wake after sleep onset (WASO). Subjective sleep predictors were self-reported poor sleep (Pittsburgh Sleep Quality Index [PSQI] > 5), excessive daytime sleepiness (EDS, Epworth Sleepiness Scale Score > 10), and TST. Cognitive outcomes were measured with the Modified Mini-Mental State examination (3MS), the Trails B test, and the Digit Vigilance Test (DVT). After adjustment for multiple potential confounders, WASO was modestly related to poorer cognition. Compared to those with WASO < 90 min, men with WASO ≥ 90 min took 6.1 sec longer to complete the Trails B test and had a 0.9-point worse 3MS score, on average (P<0.05). Actigraphically measured long sleepers had a slightly worse 3MS score compared to those with 7-8 h of sleep, but had similar Trails B and DVT completion times. Compared to those who self-reported sleeping 7-8 h, long sleepers (>8 h) on average took 8.6 sec more to complete the Trails B test, had a 0.6-point worse 3MS score, and took 46 sec longer to complete the DVT (P<0.05). PSQI and EDS were not independently related to cognitive outcomes.
  
  
  CONCLUSIONS
  There were modest cross-sectional associations of WASO and self-reported long sleep with cognition among older community-dwelling men. EDS and PSQI were not related to cognition.
authors.affiliation: Research Institute, California Pacific Medical Center, San Francisco, CA 94107, USA. tblackwell@sfcc-cpmc.net
authors.forename: Terri
authors.initials: T
authors.lastname: Blackwell
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Alison
authors.initials: A
authors.lastname: Laffan
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
mesh_terms: D056044:Actigraphy; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D009930:Organic Chemicals; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000503:physiopathology
chemical_list: D009930:Organic Chemicals; C007155:cruzin