Metformin and Joint Replacement Study

Globally, the number of total knee replacement (TKR) and total hip replacement (THR) surgeries is on the rise. One of the main reasons for this increase is osteoarthritis, for which no medications are currently available for prevention or reversal of the disease. Many times, the joint pain and disability are severe enough to require knee and hip replacements.

Researchers have found in a new study that metformin use in patients with type 2 diabetes mellitus (DM) was associated with a significantly reduced risk of total joint replacement, largely due to osteoarthritis. The study demonstrated that metformin use in patients with type 2 DM was associated with significantly reduced risks (around 30%) of total joint replacement largely due to osteoarthritis (OA), suggesting a potential therapeutic effect of metformin on OA.

The study has been published in the Canadian Medical Association Journal.

Observational studies examining the associations of metformin use with OA-related endpoints are rare and inconclusive. While two studies reported that metformin use was associated with reduced annual loss of medial cartilage volume or joint replacement surgery, another study reported no significant association between metformin use and the risk of OA occurrence among patients with type 2 DM. To our knowledge, there is no previous study investigating whether sole metformin use was associated with reduced risk of TKR and/or THR in patients with type 2 DM using population-level data. Therefore, the aim of this study is to examine if metformin prescription is associated with reduced risks of TKR and/or THR in patients with type 2 DM by using a nationwide database of Taiwan's National Health Insurance (NHI).

A team of researchers from China, Taiwan, and Australia aimed to determine whether metformin use was associated with a lower risk of TKR or THR, as evidence to date has been sparse and inconclusive. They analyzed data from 69,706 participants who received a diagnosis of type 2 diabetes in Taiwan between 2000 and 2012 and compared the risk of TKR and/or THR between people taking metformin and those not taking metformin. The mean age was 63 years, and half were women. About 90% of total joint replacements were related to osteoarthritis.

"We found that metformin use in patients with type 2 diabetes mellitus was associated with a significantly reduced risk of joint replacement, suggesting a potential therapeutic effect of metformin in patients with osteoarthritis," writes Dr. Changhai Ding, Clinical Research Center of Zhujiang Hospital, Southern Medical University, Guangzhou, China, with coauthors.

The authors call for randomized controlled trials to determine if metformin use is effective in patients with osteoarthritis.

Reference

Zhaohua Zhu, Jing-Yang Huang, Guangfeng Ruan, Peihua Cao, Shibo Chen, Yan Zhang, Weiyu Han, Tianyu Chen, Xiaoyan Cai, Jia Liu, Yujin Tang, Na Yu, Qian Wang, David J. Hunter, James Cheng-Chung Wei, and Changhai Ding. CMAJ December 19, 2022, 194 (49) E1672-E1684; DOI: https://doi.org/10.1503/cmaj.220952