Metformin lowers risk of osteoarthritis in type 2 diabetes patients: JAMA

In comparison to sulfonylurea medication, metformin treatment was linked with a significantly lower risk of developing osteoarthritis (OA) in a large, nationwide cohort study of people with diabetes, says an article published in the Journal of American Medical Association.

Strong epidemiological evidence is insufficient, although metformin may have a protective relationship against developing osteoarthritis. In order to examine the risk of OA and joint replacement in people with type 2 diabetes treated with metformin against a sulfonylurea, Matthew Baker and colleagues conducted this study.

Between December 2003 and December 2019, claims data from the Optum de identified Clinformatics Data Mart Database were used in this retrospective cohort analysis. Participants comprised people with type 2 diabetes who were 40 years of age or older and had been continuously enrolled for at least a year. Excluded from the study were people who had type 1 diabetes, OA, inflammatory arthritis, or a joint replacement in the past. Age, race, sex, Charlson comorbidity score, and treatment duration were used in time-conditional propensity score matching to construct a common new-user cohort. Data was examined between April and December 2021. The outcomes of interest were joint replacement and incident OA. To determine the adjusted hazard ratios (aHRs) of incident OA and joint replacement, Cox proportional hazard models were utilized.

The key findings of this study were:

20 937 people made up each of the metformin and control groups after time-conditional propensity score matching. 

In the adjusted analysis, metformin treatment decreased the chance of developing OA by 24% compared to sulfonylurea treatment, but there was no significant change in the risk of joint replacement. 

The risk of developing OA remained lower in those on metformin compared to those taking a sulfonylurea in the sensitivity analysis, and the risk of needing a joint replacement was not statistically significant.

Future interventional studies using metformin for the treatment and prevention of OA should be taken into consideration. Our findings confirm preclinical and observational evidence that indicate metformin may have a protective relationship against the development of OA.

Reference: 

Baker, M. C., Sheth, K., Liu, Y., Lu, D., Lu, R., & Robinson, W. H. (2023). Development of Osteoarthritis in Adults With Type 2 Diabetes Treated With Metformin vs a Sulfonylurea. In JAMA Network Open (Vol. 6, Issue 3, p. e233646). American Medical Association (AMA). https://doi.org/10.1001/jamanetworkopen.2023.3646