Influence of Knee Osteoarthritis on Exercise Capacity and Quality of Life in Obese Adults

OBJECTIVE: The objective was to determine whether knee osteoarthritis (OA) reduces exercise ambulatory capacity and impairs quality of life (QOL) in obese individuals. RESEARCH METHODS AND PROCEDURES: There were 56 subjects, with and without knee OA, who were obese. The subjects were evaluated with anthropometric measurements, a body composition assessment, maximal cardiopulmonary exercise test, 6-minute walk test (6-MWT), perceived exertion (RPE), self-reported disability Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Medical Outcomes Study Short Form 36 (SF-36). RESULTS: VO2peak was significantly higher in the controls when compared with the patients (mean +/- standard deviation, 1.584 +/- 0.23 L/kg per min vs. 0.986 +/- 0.20 L/kg per min; p < 0.001). Obese subjects without knee OA walked a significantly longer distance in the 6-MWT than obese patients with knee OA (p < 0.001). We also observed significant negative correlation between VO2max and RPE, WOMAC pain and physical limitation, and bodily pain and general health domains of short-form 36. DISCUSSION: Knee OA reduces exercise and ambulatory capacity and impairs QOL in obese individuals. RPE, WOMAC pain, and SF-36 items might provide information about exercise capacity in the obese subjects with knee OA. Our study confirms that exercise capacity and QOL might be improved by energetic and intensive treatment of pain resulting from knee OA.