title: Weight change, weight change intention, and the incidence of mobility limitation in well-functioning community-dwelling older adults.
abstract: BACKGROUND
  Obesity increases the risk for functional decline in later years, but the functional consequences of weight change in older adults are currently unclear. The aim of this study was to determine whether weight, weight change, and weight change intention are associated with risk for mobility limitation in elderly persons.
  
  
  METHODS
  This study included 2,932 well-functioning black and white men and women aged 70 to 79 years, participating in the Health, Aging and Body Composition (Health ABC) Study, who were followed for 30 months. At baseline, reported weight change of 5 or more pounds during the previous year and weight change intention were assessed. Mobility limitation was defined as reported difficulty or inability to walk one-quarter mile or to climb 10 steps during two consecutive semiannual assessments during a period of 30 months.
  
  
  RESULTS
  Approximately 30% of participants developed mobility limitation. Higher body mass index (BMI) was associated with increased risk for mobility limitation. Unintentional weight loss in the previous year was associated with increased risk for mobility limitation in the extremely obese, which was defined as BMI >or= 35 (hazard ratios [HR], =3.79; 95% confidence interval [CI], 1.84--7.79), and the normal BMI, which was defined as BMI<25 (HR, 2.55; 95% CI, 1.80--3.60). In persons with BMI 25 to 29.9, intentional weight loss (HR, 1.59; 95% CI, 1.12--2.25) and weight fluctuation with any intention (HR, 1.59; 95% CI, 1.10--2.28) increased the risk for mobility limitation. Unintentional weight gain or fluctuation did not confer additional risk for mobility limitation compared with weight stability, regardless of the level of body weight.
  
  
  CONCLUSIONS
  In this cohort of well-functioning elderly persons, functional consequences of past weight change depended on the type of weight change, intentionality, and current measured body weight.
authors.affiliation: Healthy Aging Research Program, Department of Epidemiology, University of Pittsburgh, PA 15213, USA. jung-sun.lee@mail.cscc.unc.edu
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Lee
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Frances
authors.initials: F
authors.lastname: Tylavsky
authors.forename: Tamara
authors.initials: T
authors.lastname: Harris
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Susan M
authors.initials: SM
authors.lastname: Rubin
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008124:Locomotion; D008297:Male; D009765:Obesity / Q000473:pathology / Q000503:physiopathology; D010414:Pennsylvania; D012111:Residence Characteristics; D013714:Tennessee; D015430:Weight Gain / Q000502:physiology; D015431:Weight Loss / Q000502:physiology