After a study involving a top-selling diabetes drug, rosiglitazone (Avandia), pharmaceutical giant GlaxoSmithKline started marketing the drug as a medicine to prevent type 2 diabetes in those with prediabetes (impaired glucose tolerance or impaired fasting glucose). But clinical trials can backfire. In this case, rosiglitazone did successfully lower the risk of diabetes, but at the cost of an increased risk of cardiovascular (CV) events.
This is a disturbing finding, notes Steven E. Nissen, MD, chairman of the department of cardiovascular medicine at the Cleveland Clinic and president of the American College of Cardiology. Dr. Nissen says that drugs to prevent and treat diabetes should decrease cardiovascular events, not increase them, since 65% of all diabetics die from cardiovascular complications.
The Study
In the trial known as DREAM (Diabetes REduction Assessment with ramipril and rosiglitazone Medication), researchers found that rosiglitazone reduced by 62% the number of individuals with prediabetes who developed diabetes. Elevated blood sugar (higher than normal), referred to as prediabetes, has received increasing attention from medical experts in recent years, since it puts people at a higher risk of developing full-blown diabetes. Unfortunately, that benefit was offset, as rosiglitazone also slightly increased the incidence of adverse cardiovascular events—such as heart attacks, stroke and most notably heart failure.
The results were very surprising, given that rosiglitazone is not a new drug, says Dc. Nissen. It has been available for many years and is used by hundreds of thousands of Americans. While the increase in cardiovascular problems overall did not meet the standard for statistical significance (with the exception of heart failure), in Dr. Nissen's view, it still raises serious concerns.
Safer Alternatives
Based on his analysis of the DREAM study, use of rosiglitazone to prevent diabetes should not be recommended, says Dr. Nissen. He adds that it should now be used cautiously in diabetics, particularly in those with a CV history. Fortunately, this is not your sole alternative. Dr. Nissen points out those lifestyle alterations (a healthier diet, regular exercise, weight management, etc.) have met with excellent results in preventing or treating type 2 diabetes. And, if necessary, other medications, including metformin (Glucophage) have also proven effective in controlling high blood sugar.
