Taking metformin for type 2 diabetes may offer protection against developing osteoarthritis compared with taking a sulfonylurea (such as glyburide, glipizide, or glimepiride), according to a new study published in the journal JAMA Network Open.
Metformin is widely considered the first-line prescription drug for type 2 diabetes, and it’s one of the most widely prescribed drugs in the world. In addition to its beneficial effect on blood glucose levels, metformin is linked to a wide range of other health benefits in people who take it for type 2 diabetes — including lower risks of developing dementia (advanced cognitive impairment), certain forms of cancer, and neurodegenerative diseases. Taking the drug is also linked to a lower risk of dying from pneumonia and a lower likelihood of needing joint replacement. The reason behind all of these health benefits may be the effect of metformin on cellular function throughout the body. Unfortunately, many people with newly diagnosed type 2 diabetes stop taking metformin soon after starting on the drug, for reasons that remain somewhat unclear.
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For the latest study, researchers looked at a group of 41,874 people with type 2 diabetes ages 40 and older who were taking either metformin or a sulfonylurea as a diabetes treatment. Each drug group contained 20,937 participants, and the two groups were matched based on their age, sex, race or ethnicity, diabetes treatment duration, and other health conditions. Participants were followed between December 2003 and December 2019, and members of each group took their prescribed diabetes drug for at least 90 days. New cases of osteoarthritis were recorded throughout the study period, based on drug or diagnosis codes in participants’ medical records.
Metformin use linked to lower osteoarthritis risk
The researchers found that compared with participants who took a sulfonylurea, those who took metformin were 24% less likely to develop osteoarthritis. They were also 20% less likely to undergo joint replacement, but this second difference was not statistically significant — meaning it could have been due to chance alone. To confirm their findings, the researchers performed what’s known as a sensitivity analysis — in this case, they calculated the results looking only at participants who had only ever taken either metformin or a sulfonylurea as a diabetes drug. The results of the sensitivity analysis showed that taking metformin was linked to a 23% lower risk of developing osteoarthritis, along with a nonsignificant 4% higher chance of undergoing joint replacement.
“Our study provides further, robust epidemiological evidence that metformin may be associated with protection in the development and progression of [osteoarthritis] in individuals with type 2 diabetes,” the researchers wrote, while noting that future studies in which metformin is prescribed as an intervention could provide even stronger evidence of a protective effect against osteoarthritis.
Want to learn more about metformin? Read “What to Know About Metformin,” “Diabetes Medicine: Metformin,” and “Metformin: The Unauthorized Biography.”
