Metformin could lower the risk of joint replacement in type 2 diabetes patients

The clinical trial included over 40,000 patients with type 2 diabetes.
Mert Erdemir
Magnetic resonance imaging of a knee joint.
Magnetic resonance imaging of a knee joint.

mr.suphachai praserdumrongchai/iStock 

A collaborative study conducted by researchers from China, Taiwan, and Australia has found that metformin use in patients with type 2 diabetes could reduce the risk of joint replacement resulting from "osteoarthritis."

Diabetes mellitus is a known risk factor for osteoarthritis regardless of body mass index, and previous research has shown that insulin resistance also aids in the growth of osteoarthritis. Because of its glucose-lowering effect and safety profile, metformin is frequently the first drug used to treat diabetes mellitus and is the most commonly prescribed prescription globally for individuals with this illness.

On the other hand, osteoarthritis is a chronic condition that causes severe pain and stiffness in joints. If the symptoms are intense, it may be necessary for a patient to go through total knee replacement (TKR) or total hip replacement (THR) surgeries. The condition is quite common; by 2030, the demand for TKR and THR in the U.S. is expected to reach 572,000 annually.

As of today, no drug can either stop or reverse osteoarthritis. Therefore, the research team sought to determine if metformin usage could decrease the risk of TKR or THR.

Metformin could lower the risk of joint replacement in type 2 diabetes patients
Metformin stock image.

Metformin reduces the risk of TKR or THR

The clinical trial was conducted on patients who were diagnosed with type 2 diabetes between the years 2000 and 2012 from the Taiwan National Health Insurance Research Database. Including 40,694 patients, among which 20,347 were treated with metformin and 20,347 were not given metformin, the subjects had a median age of 63.

During the clinical trial, researchers compared the results of those treated with metformin and those not given the drug and found that daily use of metformin lowers the risk of TKR or THR by up to 30 percent.

"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 in the study paper.

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According to the study paper, the findings point to metformin's potential therapeutic value for osteoarthritis patients. Randomized controlled clinical trials are needed to ascertain the efficacy of metformin in osteoarthritis patients.

The study was published in Canadian Medical Association Journal.

Abstract:

Background: It is uncertain whether metformin use is associated with reduced risk of joint replacement in patients with type 2 diabetes mellitus. We aimed to establish whether metformin use was associated with a reduced risk of total knee replacement (TKR) or total hip replacement (THR) among these patients.

Methods: We selected patients with type 2 diabetes mellitus that was diagnosed between 2000 and 2012 from the Taiwan National Health Insurance Research Database. We used prescription time-distribution matching and propensity-score matching to balance potential confounders between metformin users and nonusers. We assessed the risks of TKR or THR using Cox proportional hazards regression.

Results: We included 20 347 participants who were not treated with metformin and 20 347 who were treated with metformin, for a total of 40 694 participants (mean age 63 yr, standard deviation 11 yr; 49.8% were women) after prescription time-distribution matching. Compared with participants who did not use metformin, those who used metformin had lower risks of TKR or THR (adjusted hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.60–0.81 for TKR or THR; adjusted HR 0.71, 95% CI 0.61–0.84 for TKR; adjusted HR 0.61, 95% CI 0.41–0.92 for THR) after adjustment for covariates. Propensity-score matching analyses (10 163 participants not treated with metformin v. 10 163 treated with metformin) and sensitivity analyses using inverse probability of treatment weighting and competing risk regression showed similar results.

Interpretation: Metformin use in patients with type 2 diabetes mellitus was associated with a significantly reduced risk of total joint replacement. Randomized controlled clinical trials in patients with osteoarthritis are warranted to determine whether metformin is effective in decreasing the need for joint replacement.