title: The effects of weight and physical activity change over 20 years on later-life objective and self-reported disability.
abstract: BACKGROUND
  Weight and health behaviours are known to affect physical disability; however the evidence exploring the impact of changes to these lifestyle factors over the life course on disability is inconsistent. We aimed to explore the roles of weight and activity change between mid and later life on physical disability.
  
  
  METHODS
  Baseline and 20-year clinical follow-up data were collected from 1418 men and women, aged 58-88 years at follow-up, as part of a population-based observational study based in north-west London. At clinic, behavioural data were collected by questionnaire and anthropometry measured. Disability was assessed using a performance-based locomotor function test and self-reported questionnaires on functional limitation and basic activities of daily living (ADLs).
  
  
  RESULTS
  At follow-up, 39% experienced a locomotor dysfunction, 24% a functional limitation and 17% an impairment of ADLs. Weight gain of 10-20% or >20% of baseline, but not weight loss, were associated with increased odds of a functional limitation [odds ratio (OR) 1.69, 95% confidence interval (CI) 1.14-2.49 and OR 2.74, 1.55-4.83, respectively], after full adjustment for covariates. The same patterns were seen for the other disability outcomes. Increased physical activity reduced, and decreased physical activity enhanced the likelihood of disability, independent of baseline behaviours and adiposity. The adverse effects of weight gain appeared to be lessened in the presence of increased later-life physical activity.
  
  
  CONCLUSIONS
  Weight and activity changes between mid and later life have strong implications for physical functioning in older groups. These findings reinforce the importance of the maintenance of healthy weight and behaviour throughout the life course, and the need to promote healthy lifestyles across population groups.
authors.affiliation: International Centre for Circulatory Health, Imperial College London, London, UK emily.williams@ucl.ac.uk.
authors.forename: Emily D
authors.initials: ED
authors.lastname: Williams
authors.affiliation: International Centre for Circulatory Health, Imperial College London, London, UK.
authors.forename: Sophie V
authors.initials: SV
authors.lastname: Eastwood
authors.affiliation: International Centre for Circulatory Health, Imperial College London, London, UK.
authors.forename: Therese
authors.initials: T
authors.lastname: Tillin
authors.affiliation: International Centre for Circulatory Health, Imperial College London, London, UK.
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
authors.affiliation: International Centre for Circulatory Health, Imperial College London, London, UK.
authors.forename: Nishi
authors.initials: N
authors.lastname: Chaturvedi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D015444:Exercise; D005260:Female; D006304:Health Status; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D057566:Self Report; D012959:Socioeconomic Factors; D015430:Weight Gain; D015431:Weight Loss
keywords: Disability; Obesity; Older age; Physical activity; Weight change