Diabetes Drugs May Help Fight Inflammation

There is growing evidence that a specific class of diabetes drugs may help fight heart disease by also fighting inflammation.

In recent years research has pointed to inflammation as a possible cause of heart disease. And early studies have hinted that the type 2 diabetes drugs Actos and Avandia may help fight heart disease not only by improving blood sugar but also by battling inflammation.

Actos and Avandia belong to the relatively new class of drugs known as thiazolidinediones, or TZDs. They improve blood sugar by reducing insulin resistance, a hallmark of type 2 diabetes. This occurs when the body does not respond as well to the blood-sugar-lowering effects of the hormone insulin.

In a newly published study, researchers compared Actos with an older type of diabetes drug that lowers blood sugar in an entirely different way and does not reduce insulin resistance.

Provocative Information

The studies included results of 173 patients who took either Actos or Amaryl for six months.

Both drugs worked equally well to control blood sugar. But Actos also improved several heart disease risk factors, including cholesterol and markers of inflammation, such as C-reactive protein.

Carotid artery wall thickness, a measure of arteries that supply the brain and an indicator of heart disease, also improved with Actos.

These benefits were not seen in the patients who took Amaryl.

The research was funded by Actos manufacturer Takeda Pharma, and is published in the June 21 issue of the Journal of the American College of Cardiology.

“This is one more bit of provocative information suggesting that TZDs may be a very useful class of drugs for preventing heart disease,” American Diabetes Association (ADA) president Robert Rizza, MD, tells WebMD.

“We won’t know for sure, though, until we see the results from ongoing studies examining the question.”

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Heart Disease, Stroke Leading Causes of Death

Heart disease and stroke are the leading causes of death among people with diabetes, with two out of three diabetes patients eventually dying from one of these conditions.

According to one the new study’s researchers, it makes sense that the TZDs would protect against heart attack and stroke because insulin is active in the lining of the blood vessels. The drugs’ insulin-resistance properties may help reduce inflammation within the lining of the vessels. And less inflammation may mean less heart disease and stroke.

But Andreas Pfutzner, MD, PhD, agrees that larger clinical trials are needed to clarify the true significance of the findings.

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Concerns and a Troubled Past

Because Actos and Avandia can cause fluid retention, they are not recommended for people with moderate to severe heart failure.

In a study reported in September of 2003, University of Texas researchers identified six cases of congestive heart failureamong diabetes patients taking the drugs. They concluded that people with diabetes who have mild heart disease or any problems with their kidneys could be at greater risk of developing heart failure if they take Actos or Avandia.

And the first TZD, sold as Rezulin, was blamed for roughly 60 deaths from liver failure and was taken off the market in the spring of 2000. Some critics have expressed similar concerns about the two remaining TZDs, but they are widely considered to be safe alternatives to Rezulin.

By Salynn Boyles, reviewed by Michael W. Smith, MD

SOURCES: Pfutzner, A. Journal of the American College of Cardiology, June 21, 2005; vol. 45: pp. 1925-1931. Andreas Pfutzner, MD, PhD, Institute for Clinical Research and Development, Mainz, Germany and the University of Applied Sciences, Rheinbach, Germany. Robert Rizza, MD, president, American Diabetes Association; professor of medicine, diabetes, endocrinology, nutrition and metabolism division, Mayo Clinic College of Medicine, Rochester, Minn.