Sodium–glucose co-transporter-2 inhibitors vs metformin in reducing osteoarthritis risk: a retrospective cohort study of health insurance claims and check-up data

We aimed to compare the incidence of osteoarthritis between individuals receiving metformin, the most common anti-hyperglycemic drug, and sodium-glucose co-transporter-2 inhibitors (SGLT-2is). This new-user comparative effectiveness study included individuals aged ≥40 yr in the DeSC claims database (DeSC Healthcare Inc.), with health check-up data from April 2014 to August 2023. Individuals initiated on SGLT-2is were compared with those who were initiated on metformin. The primary outcome was knee osteoarthritis, and the secondary outcomes were hip and hand osteoarthritis. After propensity score matching, Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% CIs. In total, 37 171 individuals were included in the study. Of these, 19 216 (68%) were male, and the mean age was 67 yr (SD, 11 yr). After propensity-score matching, the HRs for incident osteoarthritis with SGLT-2is compared with metformin were 1.03 (95% CI: 0.89-1.19) for the knee, 0.95 (95% CI: 0.63-1.43) for the hip, and 1.38 (95% CI: 0.92-2.07) for the hand. Considering the risk of developing osteoarthritis, SGLT-2is may be a viable alternative to metformin for individuals with diabetes.