title: Impact of obesity on disability, function, and physical activity: data from the Osteoarthritis Initiative.
abstract: OBJECTIVE
  Older adults with obesity are at risk for osteoarthritis (OA) and are predisposed to functional decline and disability. We examined the association between obesity and disability, physical activity, and quality of life at 6 years.
  
  
  METHODS
  Using data from the longitudinal Osteoarthritis Initiative (OAI), we analysed older adults (age ≥ 60 years) with a body mass index (BMI) at baseline ≥ 18.5 kg/m(2) (n = 2378) using standard BMI categories. Outcomes were assessed at the 6-year follow-up and included: the Late-Life Function and Disability Index (LLDI), the 12-item Short Form Health Survey (SF-12), and the Physical Activity Scale for the Elderly (PASE). Linear regression predicted outcomes based on BMI category, adjusting for age, sex, race, education, smoking, cohort status, radiographic knee OA, co-morbidity scores, and baseline scores when available.
  
  
  RESULTS
  Follow-up data were available for 1727 (71.9%) participants (mean age 67.9 ± 5.3 years; 61.6% female). At baseline, obese subjects compared to overweight and normal were on a greater number of medications (4.28 vs. 3.63 vs. 3.32), had lower gait speeds (1.22 vs. 1.32 vs. 1.36 m/s), higher Charlson scores (0.59 vs. 0.37 vs. 0.30), and higher Western Ontario and McMaster University OA Index (WOMAC) scores (right: 14.8 vs. 10.3 vs. 7.5; left: 14.4 vs. 9.9 vs. 7.5). SF-12 scores at 6 years were lower in obese patients than in overweight or normal [99.5 (95% CI 98.7-100.4) vs. 101.1 (95% CI 100.4-101.8) vs. 102.8 (95% CI 101.8-103.8)], as were PASE scores [115.1 (95% CI 110.3-119.8) vs. 126.2 (95% CI 122.2-130.2) vs. 131.4 (95% CI 125.8-137.0)]. The LLDI limitation component demonstrated differences in obese compared to overweight or normal [78.6 (95% CI 77.4-79.9) vs. 81.2 (95% CI 80.2-82.3) vs. 82.5 (95% CI 81.1-84.0)].
  
  
  CONCLUSIONS
  Obesity was associated with worse physical activity scores, lower quality of life, and higher risk of 6-year disability.
authors.affiliation: a Section of General Internal Medicine, Dartmouth-Hitchcock Medical Center , Lebanon , NH , USA.|b Centers for Health and Aging, Dartmouth College , Lebanon , NH , USA.|c Geisel School of Medicine at Dartmouth , Hanover , NH , USA.|d The Dartmouth Institute, Dartmouth College , Lebanon , NH , USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Batsis
authors.affiliation: b Centers for Health and Aging, Dartmouth College , Lebanon , NH , USA.|c Geisel School of Medicine at Dartmouth , Hanover , NH , USA.|d The Dartmouth Institute, Dartmouth College , Lebanon , NH , USA.|e Section of Rheumatology, Dartmouth-Hitchcock Medical Center , Lebanon , NH , USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Zbehlik
authors.affiliation: b Centers for Health and Aging, Dartmouth College , Lebanon , NH , USA.|c Geisel School of Medicine at Dartmouth , Hanover , NH , USA.|d The Dartmouth Institute, Dartmouth College , Lebanon , NH , USA.
authors.forename: L K
authors.initials: LK
authors.lastname: Barre
authors.affiliation: a Section of General Internal Medicine, Dartmouth-Hitchcock Medical Center , Lebanon , NH , USA.|b Centers for Health and Aging, Dartmouth College , Lebanon , NH , USA.|c Geisel School of Medicine at Dartmouth , Hanover , NH , USA.|d The Dartmouth Institute, Dartmouth College , Lebanon , NH , USA.
authors.forename: J P W
authors.initials: JP
authors.lastname: Bynum
authors.affiliation: f Department of Physical Medicine and Rehabilitation , Dartmouth-Hitchcock Medical Center , Lebanon , NH , USA.
authors.forename: D
authors.initials: D
authors.lastname: Pidgeon
authors.affiliation: b Centers for Health and Aging, Dartmouth College , Lebanon , NH , USA.|c Geisel School of Medicine at Dartmouth , Hanover , NH , USA.|d The Dartmouth Institute, Dartmouth College , Lebanon , NH , USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Bartels
mesh_terms: D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000150:complications* / Q000503:physiopathology* / Q000523:psychology; D020370:Osteoarthritis, Knee / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology; D012307:Risk Factors