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.