title: Prospective change in daily walking over 2 years in older adults with or at risk of knee osteoarthritis: the MOST study.
abstract: OBJECTIVE
  Radiographic disease and knee pain are thought to decrease physical activity in people with knee osteoarthritis (OA), but this has not been formally studied. We examined change in objectively measured daily walking over 2 years and evaluated the association of certain risk factors with reduced walking among adults with or at risk of knee OA.
  
  
  METHODS
  Steps/day over 7 days were collected at baseline and 2 years later in subjects with or at risk of knee OA from the Multicenter Osteoarthritis Study using a StepWatch. We evaluated the presence of radiographic knee osteoarthritis (ROA), knee pain, worsening of ROA and pain over 2 years, obesity, depressive symptoms, living situation, catastrophizing, fatigue, widespread pain and comorbidities with 2-year change in daily walking using regression models adjusted for potential confounders.
  
  
  RESULTS
  1318 met inclusion criteria (age 66.9 ± 7.7, 59% women, BMI 30.6 ± 5.9) and walked 126 ± 1700 steps/day fewer steps at 2 years (95% CI [-218, -35]). People with depressive symptoms at baseline walked 455 fewer steps/day [-872, -68], and there was a trend for people with ROA worsening to walk 183 fewer steps/day [-377.5, 11.7]. No other factors met statistical significance for change in daily walking.
  
  
  CONCLUSIONS
  Adults with or at risk of knee OA experienced only minimal declines in daily walking over 2 years. Nonetheless, depressive symptoms and may be worsening ROA are associated with a decline in steps/day in adults with or at risk of knee OA.
authors: Department of Physical Therapy, University of Delaware, Newark, DE, USA. Electronic address: dkw@udel.edu.
authors: D K
authors: DK
authors: White
authors: Department of Kinesiology, University of Massachusetts Amherst, Amherst MA, USA.
authors: C
authors: C
authors: Tudor-Locke
authors: Boston University School of Medicine, Boston, MA, USA.
authors: Y
authors: Y
authors: Zhang
authors: Boston University School of Medicine, Boston, MA, USA.
authors: J
authors: J
authors: Niu
authors: Boston University School of Medicine, Boston, MA, USA.
authors: D T
authors: DT
authors: Felson
authors: Boston University School of Medicine, Boston, MA, USA; MGH Institute of Health Professions, Boston, MA, USA.
authors: K D
authors: KD
authors: Gross
authors: University of San Francisco, San Francisco, CA, USA.
authors: M C
authors: MC
authors: Nevitt
authors: University of Alabama, Birmingham, AL, USA.
authors: C E
authors: CE
authors: Lewis
authors: University of Iowa, Iowa City, IA, USA.
authors: J
authors: J
authors: Torner
authors: Boston University School of Medicine, Boston, MA, USA.
authors: T
authors: T
authors: Neogi
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000150:complications / Q000503:physiopathology*; D003863:Depression / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology*; D011446:Prospective Studies; D012306:Risk; D016138:Walking
keywords: Daily walking; Knee osteoarthritis; Physical activity