title: Longitudinal changes in body mass index and body composition over 3 years and relationship to health outcomes in Hong Kong Chinese age 70 and older.
abstract: OBJECTIVE
  To determine longitudinal changes in body mass index (BMI) and body composition with age and the relationship between these changes with mortality, morbidity, functional capacity, and other health outcome measures.
  
  
  METHODS
  A 3-year longitudinal study of a random sample of community-living subjects.
  
  
  METHODS
  Older Chinese in the Hong Kong Special Administrative Region of China.
  
  
  METHODS
  Two thousand and thirty-two Chinese subjects age 70 and older recruited territory-wide by proportional random sampling.
  
  
  METHODS
  Baseline information collected included medical history, self-perceived health, Barthel Index, Geriatric Depression Score, time taken to complete a 16-foot walk, height, weight, mid-arm circumference, arm skin-fold thickness, and waist/hip ratio. Body composition was calculated from prediction equation. Outcome measures included mortality, development of new diseases, Barthel Index, time taken for 16-foot walk, self-perceived health, and Geriatric Depression Score.
  
  
  RESULTS
  All parameters, with the exception of triceps skin-fold thickness in men, decreased, regardless of presence or absence of disease. The decrease in arm circumference, triceps skin-fold thickness, and total body fat (TBF) was greater in women than in men, whereas men had a greater decrease in fat-free mass (FFM). Even in the absence of disease, three times as many subjects lost > or =5kg in weight as gained > or =5kg (15% vs. 5%), and only age could be identified as a contributing factor to this weight loss. In the absence of disease, lower anthropometric indices were associated with greater mortality, development of new disease (in women only), dependency, and poor performance measure. Waist-hip ratio was not associated with mortality or any other health outcomes. Decrease in both FFM and TBF were associated with worse outcomes, the effect being more marked in women.
  
  
  CONCLUSIONS
  In the older population, changes in weight and body composition occur even in the absence of disease and are associated with mortality and physical functioning level. Weight loss rather than weight gain appears to be more important in this population, and promotion of life-style interventions targeted at weight maintenance would be important.
authors.affiliation: Department of Medicine and Therapeutics and Department of Community and Family Medicine, The Chinese University of Hong Kong, Hong Kong.
authors.forename: J
authors.initials: J
authors.lastname: Woo
authors.forename: S C
authors.initials: SC
authors.lastname: Ho
authors.forename: A
authors.initials: A
authors.lastname: Sham
mesh_terms: D000203:Activities of Daily Living; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D002681:China / Q000208:ethnology; D003863:Depression / Q000150:complications / Q000175:diagnosis; D005260:Female; D015577:Geriatric Assessment; D006304:Health Status; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule; D009017:Morbidity; D009026:Mortality; D009765:Obesity / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D011159:Population Surveillance; D011237:Predictive Value of Tests; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D013997:Time Factors