Healthcare (Commonwealth Union) – A widely used diabetes medication may help ease knee osteoarthritis pain in individuals who are overweight or obese, potentially postponing the need for knee replacement surgery, according to new research led by Monash University.
The drug, metformin — typically prescribed for managing type 2 diabetes — was found to significantly lessen knee arthritis pain over a six-month period in a clinical study published in JAMA.
The randomized trial evaluated whether metformin could better relieve knee pain than a placebo in people suffering from symptomatic knee osteoarthritis (OA) and carrying excess weight.
Conducted entirely via telehealth, the study involved 107 participants (73 women and 34 men) with an average age of 60. Some participants received up to 2000 mg of metformin daily for six months, while others were given a placebo. None of the participants had diabetes.
Researchers measured knee pain on a scale from 0 to 100, where 100 indicated the highest level of pain. After six months, the group taking metformin experienced a 31.3-point decrease in pain, compared to an 18.9-point reduction among those taking the placebo — a result classified as a moderate improvement.
The findings support the use of metformin as a treatment option for symptomatic knee osteoarthritis (OA) in individuals who are overweight or obese, the researchers reported. However, they noted that due to the relatively small sample size, larger clinical trials are needed to confirm these results.
Lead researcher Professor Flavia Cicuttini, head of the Musculoskeletal Unit at Monash University and Head of Rheumatology at The Alfred, said the study suggests metformin could offer a promising, cost-effective new option for easing knee pain in people with knee OA and excess weight.
Current management strategies for knee OA typically involve lifestyle modifications such as exercise and weight reduction, which many patients find challenging. Available medications, like paracetamol, topical anti-inflammatory agents, and oral anti-inflammatory drugs, offer only limited relief and may not be suitable for everyone due to safety concerns.
Australia has not seen the approval of new OA medications since the introduction of Celebrex (celecoxib) and Vioxx (rofecoxib) in the late 1990s.
Professor Cicuttini pointed out that there are few effective options for relieving knee pain caused by osteoarthritis. As a result, patients and clinicians often turn to alternative measures, including surgical intervention.
This has contributed to significant challenges in managing knee OA both in Australia and around the world, including a rise in the number of knee replacement surgeries being carried out at earlier stages of the disease. This trend reflects the perception that treatment options for knee OA are limited and that knee replacements have long-lasting outcomes.
“At first glance this may seem reasonable, but it is a major problem because patient dissatisfaction with knee replacements is already high at between 20-30 per cent, even when the operation is technically perfect,” explained Professor Cicuttini. “Dissatisfaction rates are highest when the operation is done for early knee OA.
“To go through the effort and cost of a big operation like a knee replacement, only to be unhappy with the results because of ongoing pain and symptoms, is definitely low-quality care. Doing a knee replacement earlier also increases the potential need for the procedure to be redone.
Professor Cicuttini said metformin gives GPs a new option to offer patients, alongside advice on weight loss and exercise and pointed out that Metformin targets knee osteoarthritis in several ways, including by reducing low-grade inflammation and influencing key metabolic pathways. She further indicated that it offers a different approach to relieving knee pain.
Professor Cicuttini and her team are at present engaging with patients, GPs, orthopaedic surgeons, and other healthcare professionals to incorporate metformin into the knee osteoarthritis treatment pathway, aiming to enhance patient outcomes and better target the use of knee replacements.
