title: Sarcopenia, cardiopulmonary fitness, and physical disability in community-dwelling elderly people.
abstract: BACKGROUND
  Sarcopenia refers to the loss of skeletal muscle mass with aging. It is believed to be associated with functional impairment and physical disability.
  
  
  OBJECTIVE
  The purposes of this study were: (1) to compare the physical activity, muscle strength (force-generating capacity), cardiopulmonary fitness, and physical disability in community-dwelling elderly people with sarcopenia, borderline sarcopenia, and normal skeletal muscle mass in Taiwan and (2) to test the hypothesis that sarcopenia is associated with physical disability and examine whether the association is mediated by decreased muscle strength or cardiopulmonary fitness.
  
  
  METHODS
  This was a cross-sectional investigation.
  
  
  METHODS
  Two hundred seventy-five community-dwelling elderly people (148 men, 127 women) aged > or =65 years participated in the study. The participants were recruited from communities in the district of Zhongzheng, Taipei. Predicted skeletal muscle mass was estimated using a bioelectrical impedance analysis equation. The skeletal muscle mass index (SMI) was calculated by dividing skeletal muscle mass by height squared. Physical disability was assessed using the Groningen Activity Restriction Scale. Physical activity was assessed using a 7-day recall physical activity questionnaire. Cardiopulmonary fitness was assessed using a 3-minute step test, and grip strength was measured to represent muscle strength.
  
  
  RESULTS
  Cardiopulmonary fitness was significantly lower in elderly people with sarcopenia than in those with normal SMIs. Grip strength and daily energy expenditure (kcal/kg/day) were not significantly different between the participants with sarcopenia and those with normal SMIs. The odds ratio for physical disability between the participants with sarcopenia and those with normal SMIs was 3.03 (95% confidence interval=1.21-7.61). The odds ratio decreased and the significant difference diminished after controlling for cardiopulmonary fitness.
  
  
  CONCLUSIONS
  A causal relationship between sarcopenia and physical activity, cardiopulmonary fitness, and physical disability cannot be established because of the cross-sectional nature of study design.
  
  
  CONCLUSIONS
  Sarcopenia was associated with physical disability in elderly men. The association between sarcopenia and physical disability was mediated to a large extent by decreased cardiopulmonary fitness.
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Meng-Yueh
authors.initials: MY
authors.lastname: Chien
authors.forename: Hsu-Ko
authors.initials: HK
authors.lastname: Kuo
authors.forename: Ying-Tai
authors.initials: YT
authors.lastname: Wu
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D000886:Anthropometry; D001823:Body Composition; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D004562:Electrocardiography; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D055948:Sarcopenia / Q000503:physiopathology*; D011795:Surveys and Questionnaires