An Australian university has carried out research which, it says, shows that a common diabetes drug can reduce osteoarthritis pain. So, does it? YKC’s Dave Duffy unpicks a claim that’s a little more complex than it first appears.

It certainly sounds encouraging. Metformin, a drug commonly prescribed to treat type 2 diabetes, has been shown to reduce knee arthritis pain over six months. The study, conducted by Melbourne-based Monash University, took 107 participants, none of whom had diabetes but all of whom had osteoarthritis. Some received Metformin. Some took a placebo. The Metformin takers reported a 31-point reduction in pain. The placebo takers reported a 19-point reduction.

We’re not talking a vast reduction in pain, then, when comparing the two, but it’s not insignificant. But what’s actually responsible for that reduction?

A multi-factorial problem

Osteoarthritis is a multifactorial condition, meaning several things can affect and influence it. These include age, sex, genetics, injuries, lifestyle factors and more. Type 2 diabetes is multi-factorial too, influenced by genetics, diet, lifestyle choices etc. One important element common to both conditions, however, is weight.

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Losing weight can have a powerful effect on diabetes, with sustained and significant weight loss potentially sending the diabetes into remission. It can have a powerful effect on osteoarthritis too because joints that don’t have to bear as much weight are less likely to deteriorate as fast, reducing or delaying the need for knee replacement.

Weight loss is one of the most effective non-surgical treatments for osteoarthritis – it’s something I discuss with patients all the time – but it’s not traditionally been easy for obese patients with osteoarthritis (OA) to lose weight because of the pain the OA causes.

Recent weight loss drugs are changing that position, but Metformin also appears to have weight loss benefits. Evidence suggests the drug supports weight loss through appetite suppression and its effects on the gut. Figures differ depending on study, but there is a consistent picture of significant numbers of patients losing up to 5% of bodyweight.

So the question is, is the diabetes drug causing the decrease in OA pain, or is it the weight loss?

Reducing osteoarthritis knee pain: what’s the cause?

You might ask why this matters. If a patient can reduce OA pain, then does it really matter whether that’s a direct result of Metformin or weight loss enabled by Metformin?

Perhaps not. Weight definitely affects osteoarthritis. Your symptoms will get worse faster if you carry excess weight. For whatever reason, it seems Metformin may offer some moderate benefit. It’s just a little difficult to unpick the cause and effect to say with certainty where the benefit is coming from. The study itself notes a larger trial is required, and this would be important to understand the root of the benefit.

If you’re suffering from the pain of osteoarthritis, we can help. Please contact us, or phone us on 03453 052 579.

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