title: The Association Between Sleep Duration and Hand Grip Strength in Community-Dwelling Older Adults: The Yilan Study, Taiwan.
abstract: Different pathomechanisms may underlie the age-related decline in muscle mass and muscle power in older adults. This study aimed to examine the independent relationship between sleep duration and muscle power.
  
  
  
  Older adults, aged 65 years and older, were randomly selected to participate in a community-based survey in Yilan city, Taiwan. Data on self-reported sleep duration, sociodemographic information, lifestyle, chronic medical and mental health conditions, sleep-related parameters, and anthropometric measurements were collected. Participants who slept ≤4 hr, 5 hr, 6-7 hr, 8 hr, and ≥9 hr were defined as shortest, short, mid-range, long, and longest sleepers, respectively. Muscle power was estimated using hand grip strength.
  
  
  
  A total of 1081 individuals participated. Their average age was 76.3 ± 6.1 years, and 59.4% were female. After controlling for covariates, including muscle mass of the upper extremities, both long (estimated mean [95% confidence interval, CI]: 19.2 [18.2-20.2], p = .03) and longest sleepers (estimated mean [95% CI]: 17.8 [16.4-19.2], p = .001) had weaker hand grip strength than mid-range sleepers (estimated mean [95% CI]: 20.9 [20.3-21.4]). When stratified by sex, the association between longest sleep duration and weaker hand grip strength was noted among men only.
  
  
  
  Older adults with long sleep duration had weaker hand grip strength irrespective of muscle mass. This finding suggests that decreased muscle power may mediate or confound the relationship between long sleep duration and adverse health outcomes.
authors.affiliation: Department of Psychiatry & Center of Sleep Disorders, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hsi-Chung
authors.initials: HC
authors.lastname: Chen
authors.affiliation: Division of Cardiology, Department of Internal Medicine & Community Medicine Center, National Yang-Ming University Hospital, Yilan, Taiwan.|Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Nai-Wei
authors.initials: NW
authors.lastname: Hsu
authors.affiliation: Community Medicine Research Center & Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pesus
authors.initials: P
authors.lastname: Chou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D013624:Taiwan; D013997:Time Factors
keywords: hand grip strength; older adults.; sleep duration