Sex and body mass index correlate with Western Ontario and McMaster Universities Osteoarthritis Index and quality of life scores in knee osteoarthritis

Elbaz A, Debbi EM, Segal G, Haim A, Halperin N, Agar G, Mor A, Debi R. Sex and body mass index correlate with Western Ontario and McMaster Universities Osteoarthritis Index and quality of life scores in knee osteoarthritis. Objective: To examine the associations of sex, body mass index (BMI), and age with knee osteoarthritis (OA) symptomatic severity. Design: A cross-sectional retrospective analysis. Setting: Patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Data were acquired from a stored database of a private therapy center. Participants: Patients (N=1487) with symptomatic knee OA were evaluated. Interventions: Not applicable. Main Outcome Measures: WOMAC questionnaire and SF-36. Results: BMI correlated significantly with worse knee OA symptoms for all WOMAC and SF-36 subcategories (all P≤.001). Age correlated significantly with worse symptoms only for WOMAC function and SF-36 physical functioning (P=.001 and P=.009, respectively). A significant difference across BMI quintiles was found for all WOMAC and SF-36 subcategories (all P≤.01). Women showed worse knee OA symptoms in all WOMAC and SF-36 subcategories (all P≤.001). There was a significant interaction of sex by BMI in WOMAC pain and WOMAC function (P=.01 and P=.02, respectively). Conclusions: Based on the results of this analysis, it can be concluded that women and patients with a higher BMI with knee OA are at a greater risk for worse symptoms.