Abstract

Objective:To assess by meta-analysis of randomised controlled trials (RCTs) changes in pain and function when overweight patients with knee OA achieve a weight loss.

Methods:Systematic searches were performed and reference lists from the retrieved trials were searched. RCTs were enclosed in the systematic review if they explicitly stated diagnosis of knee OA and reported a weight change as the only difference in intervention from the control group. OMERACT III outcome variables were considered for analysis. Effect size (ES) was calculated using RevMan and meta-regression analyses were performed using the weighted estimates from the random effects analyses.

Results:Among 35 potential trials identified, 4 RCTs including 5 intervention/control groups met our inclusion criteria and provided data from 454 patients. Pooled ES for pain and physical disability were 0.20 (95% CI: 0.00;0.39) and 0.23 (0.04;0.42) at a weight reduction of 6.1 kg (4.7;7.6 kg). Meta-regression analysis showed that disability could be significantly improved when weight was reduced over 5.1%, or at the rate of more than 0.24% reduction per week.

Conclusion:Clinical efficacy on pain reduction was present, although not predictable following weight loss. Meta-regression analysis indicated that physical disability of patients with knee OA and overweight diminished following a moderate weight reduction regime. The analysis supported that a weight loss of more than 5% should be achieved within a 20-week period, i.e. 0.25% per week.