JAMA

Metformin may reduce knee pain in patients with osteoarthritis, obesity

April 30, 2025

Study details: This randomized, double-blind, placebo-controlled trial evaluated the effects of metformin on knee pain in patients with symptomatic knee osteoarthritis and who are overweight or obese. Conducted in Victoria, Australia, the study recruited 107 participants with a BMI of ≥25 and knee pain for ≥6 months. Participants were randomly assigned to receive either 2000 mg/day of metformin (n = 54) or placebo (n = 53) for 6 months.

Results: At 6 months, the metformin group showed a significant reduction in knee pain compared with the placebo group. The mean change in visual analog scale (VAS) pain score was -31.3 mm in the metformin group vs. -18.9 mm in the placebo group, with a between-group difference of -11.4 mm (95% confidence interval [CI], -20.1 to -2.6 mm; P = 0.01). The effect size was 0.43 (95% CI, 0.02-0.83). Common adverse events included diarrhea and abdominal discomfort, occurring more frequently in the metformin group.

Clinical impact: Metformin may be an effective treatment for reducing knee pain in patients with knee osteoarthritis and overweight or obesity. However, due to the modest sample size, further large-scale trials are warranted.

Source:

Pan F, et al. (2025, April 24). JAMA. Metformin for Knee Osteoarthritis in Patients With Overweight or Obesity: A Randomized Clinical Trial. https://pubmed.ncbi.nlm.nih.gov/40274279/