Effects of meaningful weight loss beyond symptomatic relief in adults with knee osteoarthritis and obesity: a systematic review and meta-analysis

Existing clinical guidelines recommend weight loss for adults with knee osteoarthritis and obesity, but the supporting evidence to date remains inadequate. There is also no pooled data on physical function and quality of life. This study aims to examine the efficacy of weight loss on pain, self-reported disability, physical function and quality of life in adults with knee osteoarthritis and obesity. A systematic database search (from 1990 to June 2017) was conducted, and seven studies were eligible for inclusion. The meta-analyses demonstrated that a 5% to 10% weight loss significantly improved pain (effect size 0.33, 95% confidence intervals 0.17 to 0.48), self-reported disability (effect size 0.42, 95% confidence intervals 0.25 to 0.59) and quality of life (physical) (effect size 0.39, 95% confidence intervals 0.24 to 0.54). The results were based on adults with mean body mass index 33.6 to 36.4 kg m⁻² and mild to moderate knee osteoarthritis. Results for physical function were inconclusive due to the lack of eligible studies and incomprehensive outcome measures used.