Effectiveness of weight-loss interventions for reducing pain and disability in people with common musculoskeletal disorders: A systematic review with meta-analysis

Objective: To assess the effectiveness of weight-loss interventions on pain and disability in people with knee and hip osteoarthritis (OA) and spinal pain. Design: Intervention systematic review. Literature Search: Twelve online databases and clinical trial registries. Study Selection Criteria: Randomized controlled trials of any weight-loss intervention (eg, diet, physical activity, surgical, pharmaceutical) that reported pain or disability outcomes in people with knee or hip OA or spinal pain. Data Synthesis: We calculated mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs). We used the Cochrane risk of bias tool to assess risk of bias and the Grading of Recommendations Assessment, Development, and Evaluation tool to judge credibility of evidence. Results: Twenty-two trials with 3602 participants were included. There was very low- to very low-credibility evidence for a moderate effect of weight-loss interventions on pain intensity (10 trials, n = 1806; SMD, -0.54; 95% CI: -0.86, -0.22; I2 = 87%, P<.001) and a small effect on disability (11 trials, n = 1821; SMD, -0.32; 95% CI: -0.49, -0.14; I2 = 58%, P <.001) compared to minimal care for people with OA. For knee OA, there was low- to moderate-credibility evidence that weight-loss interventions were not more effective than exercise only for pain intensity and disability, respectively (4 trials, n = 673; SMD, -0.13; 95% CI: -0.40, 0.14; I2 = 55%; 5 trials, n = 737; SMD, -0.20; 95% CI: -0.41, 0.00; I2 = 32%). Conclusion: Weight-loss interventions may provide small to moderate improvements in pain and disability for OA compared to minimal care. There was limited and inconclusive evidence for weight-loss interventions targeting spinal pain.