title: The association of waist circumference with walking difficulty among adults with or at risk of knee osteoarthritis: the Osteoarthritis Initiative.
abstract: Excess weight is a known risk factor for functional limitation and common in adults with knee osteoarthritis (OA). We asked to what extent high waist circumference was linked with developing difficulty with walking speed and distance over 4 years in adults with or at risk of knee OA.
  
  
  
  Using data from the Osteoarthritis Initiative (OAI), we employed World Health Organization (WHO) categories for Body Mass Index (BMI) and waist circumference (small/medium and large). Difficulty with speed was defined by slow gait: <1.2 m/s during a 20-m walk, and difficulty with distance was defined by an inability to walk 400 m. We calculated risk ratios (RR) to examine the likelihood of developing difficulty with distance and speed using obesity and waist circumference as predictors with RRs adjusted for potential confounders (i.e., age, sex, race, education, physical activity, and OA status).
  
  
  
  Participants with obesity and large waists were 2.2 times more likely to have difficulty with speed at 4 years compared to healthy weight and small/medium waisted participants (Adjusted RR 2.2 [95% Confidence interval (CI) 1.6, 3.1], P < .0001). Participants with obesity and a large waist circumference had 2.4 times the risk of developing the inability to walk 400 m compared with those with a healthy BMI and small/medium waist circumference (Adjusted RR 0.9 [95% CI 1.6, 3.7], P < .0001).
  
  
  
  Waist circumference may be a main risk factor for developing difficulty with speed in adults with or at risk of knee OA.
authors: Department of Occupational Therapy, Boston University, Boston, MA, USA; Department of Medicine, Boston University, Boston, MA, USA; Department of Psychological & Brain Sciences, Boston University, Boston, MA, USA. Electronic address: simvgill@bu.edu.
authors: S V
authors: SV
authors: Gill
authors: Department of Physical Therapy, University of Delaware, Newark, DE, USA.
authors: G E
authors: GE
authors: Hicks
authors: Department of Medicine, Boston University, Boston, MA, USA.
authors: Y
authors: Y
authors: Zhang
authors: Department of Medicine, Boston University, Boston, MA, USA.
authors: J
authors: J
authors: Niu
authors: Department of Medicine, Boston University, Boston, MA, USA.
authors: C M
authors: CM
authors: Apovian
authors: Department of Physical Therapy, University of Delaware, Newark, DE, USA.
authors: D K
authors: DK
authors: White
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D008124:Locomotion; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D020370:Osteoarthritis, Knee / Q000150:complications*; D012307:Risk Factors; D055105:Waist Circumference; D016138:Walking
keywords: Body mass index; Gait; Obesity; Osteoarthritis; Waist circumference; Walking