Existing arthritis drug might help fight diabetes

The growing concern of type 2 diabetes needs no introduction — so, identifying a drug that is already in circulation that might help to fight the condition would be a welcome discovery.

Type 2 diabetes is rarely out of the headlines — and for good reason. Approximately 30.3 million people in the United States have diabetes, the vast majority of whom have type 2 diabetes.

This equates to about 1 in 10 U.S. citizens. Some states are hit harder than others. In Mississipi, for instance, almost 1 in 7 residents have a diabetes diagnosis.

When you consider that about 1 in 4 people with diabetes do not yet know that they have it, the figures are nothing short of staggering.

It's all the more worrying when you remember that, although type 2 diabetes can be successfully managed in many cases, it is a condition that many will have for life. As such, diabetes is a huge burden on a person physically, mentally, and financially.

Because of the huge numbers involved and the significant suffering that it can bring, research into innovative treatments for type 2 diabetes is constantly rolling on.

In brief, type 2 diabetes is caused by lifestyle factors such as inactivity, poor diet, and obesity. It is a metabolic disorder that causes cells to stop responding to insulin. This has the effect of raising the level of sugar in the blood, which, in turn, damages the organs and systems of the body.

Alongside lifestyle interventions, many people with diabetes take medication to help keep their blood sugar levels in check. Although these can be useful, some have adverse side effects and others become less effective as they are used for longer periods of time. Researchers are keen, therefore, to find better alternatives.

Enter a rheumatoid arthritis drug

Rheumatoid arthritis is an autoimmune condition that can cause swelling, pain, and stiffness in the joints. This chronic condition affects around 1 percent of the world's population.

Interestingly, a drug that has been used to treat rheumatoid arthritis for many years might be of use for individuals with type 2 diabetes.

This might seem surprising as the two conditions are worlds apart, but some links and interactions between the two have been noted over the years.

For instance, people with rheumatoid arthritis are more likely to develop diabetes, and people with diabetes are more likely to develop rheumatoid arthritis. Also, individuals with rheumatoid arthritis who go on to develop type 2 diabetes tend to have a harder time controlling their blood sugar levels.

Leflunomide is an anti-inflammatory drug, approved by the Food and Drug Administration (FDA) for use in arthritis in 1998. Over the years, some scientists have noted that leflunomide seems to lower blood glucose levels and, in obese people, even lead to weight loss. But it has not been clear how or why these interactions occurred.

Recently, Prof. Xiulong Xu and team — from the Institute of Comparative Medicine at Yangzhou University in China — investigated this unexpected relationship in more detail.

How does leflunomide work?

To identify the action of leflunomide in individuals with type 2 diabetes, they utilized two separate mouse models for diabetes. In both models, the drug not only improved blood sugar levels but actually caused cells to begin reacting to insulin again.

The intriguing results are published this week in the Journal of Endocrinology.

"We studied how leflunomide works at a molecular level and found that it targets a protein involved in desensitizing the insulin receptor, which is responsible for instructing the cells to start absorbing sugar from the bloodstream."

Prof. Xiulong Xu

Leflunomide also works at other targets in the body, so it is possible that the anti-diabetic response involves more than one pathway. As such, Prof. Xu and his team plan to carry out more work.

He explains, "We know some inflammatory factors can also desensitize the insulin receptor, and leflunomide is an anti-inflammatory, so it may be that it controls blood sugar partly by its anti-inflammatory effect."

Although the results are encouraging, even two mouse models do not equal one human. Already, the researchers have their sights set on human trials.

Since the drug is already approved for use in humans, hopefully, taking it from rheumatoid arthritis treatment to diabetes treatment would be a relatively swift affair — that is, as long as the upcoming clinical trials back up the researchers' hypothesis, of course.