title: Knee osteoarthritis and frailty: findings from the Multicenter Osteoarthritis Study and Osteoarthritis Initiative.
abstract: BACKGROUND
  Knee osteoarthritis (OA) and frailty are two conditions that are associated with functional limitation and disability in elders, yet their relation to one another is not known.
  
  
  METHODS
  We included participants from two large, multicenter studies enriched with community dwelling older adults with knee OA (Multicenter Osteoarthritis Study and Osteoarthritis Initiative). Knee OA was defined radiographically (ROA) and symptomatically (SOA). Frailty was defined using the Study of Osteoporotic Fracture index as the presence of ≥2 of the following: (i) weight loss >5% between two consecutive visits; (ii) inability to arise from chair five times without support; (iii) poor energy. Cross-sectional and longitudinal associations of knee OA with prevalent and incident frailty, respectively, were examined using binomial regression with robust variance estimation, adjusting for potential confounders.
  
  
  RESULTS
  In the cross-sectional analyses, frailty was more prevalent among participants with ROA (4.39% vs 2.77%; PR 1.60 [1.07, 2.39]) and SOA (5.88% vs 2.79%; PR 1.92 [1. 35, 2.74]) compared with those without ROA or SOA, respectively. In the longitudinal analyses, risk of developing frailty was greater among those with ROA (4.73% vs 2.50%; RR 1.45 [0.91, 2.30]) and SOA (6.30% vs 2.83%; RR 1.66 [1.11, 2.48]) than those without ROA or SOA, respectively.
  
  
  CONCLUSIONS
  Knee OA is associated with greater prevalence and risk of developing frailty. Understanding the mechanisms linking these two common conditions of older adults would aid in identifying novel targets for treatment or prevention of frailty.
authors: Department of Medicine, Boston University School of Medicine, Massachusetts. demisra@bu.edu.
authors: Devyani
authors: D
authors: Misra
authors: Department of Medicine, Boston University School of Medicine, Massachusetts.
authors: David T
authors: DT
authors: Felson
authors: Department of Medicine, Boston University School of Medicine, Massachusetts.
authors: Rebecca A
authors: RA
authors: Silliman
authors: Department of Epidemiology and Biostatistics, University of California at San Francisco.
authors: Michael
authors: M
authors: Nevitt
authors: Department of Medicine, University of Alabama School of Medicine, Birmingham.
authors: Cora E
authors: CE
authors: Lewis
authors: Department of Epidemiology, University of Iowa.
authors: James
authors: J
authors: Torner
authors: Department of Medicine, Boston University School of Medicine, Massachusetts.
authors: Tuhina
authors: T
authors: Neogi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D053580:Muscle Strength; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*
keywords: Frailty.; Knee; Osteoarthritis