According to research presented at the American Diabetes Association’s 69th Scientific Sessions, using rosiglitazone (brand name Avandia) in combination with metformin or a sulfonylurea does not increase the risk for cardiovascular disease or death in people with Type 2 diabetes. But some scientists have met these results with skepticism, claiming that the study does not have enough statistical power to resolve any of the controversy surrounding this drug.
The Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycemia in Diabetes (RECORD) study was initiated in 2001 to determine the effects of rosiglitazone on blood glucose control and cardiovascular events. The investigators, from Newcastle University in the United Kingdom, enrolled 4,447 people with diabetes who were taking either metformin or a sulfonylurea. Roughly half of the participants were given rosiglitazone in addition to their usual medicine, while the other half of the participants were in a control group that received a combination of metformin and a sulfonylurea.
At the end of roughly six years, approximately the same number of people in both groups — 321 people in the rosiglitazone group and 323 people in the control group — had been hospitalized or had died due to a cardiovascular event, indicating that, in appropriately selected people, rosiglitazone does not present an increased risk of cardiovascular events compared to the other commonly used diabetes medicines. The research did find that rosiglitazone increases the risk of bone fracture, particularly in women, and doubles the risk of heart failure. However, in terms of overall cardiovascular risk, including the risk of heart failure, rosiglitazone was deemed to be safe.
Dr. Steven E. Nissen, who drew attention to a possible cardiovascular risk of rosiglitazone in a 2007 meta-analysis (a type of research in which statistics from several studies are combined and examined), feels that the RECORD study has serious shortcomings. In an interview with WebMD’s Heartwire, he noted that “significantly more patients in the Avandia-treatment group received statins, a class of drugs known to reduce risk of coronary events. Essentially, the study sought to neutralize the unfavorable lipid effects of the drug by administering statins more often to patients in the Avandia group. This imbalance biases the study in favor of Avandia and distorts the results.” He also indicated that over 30% of people included in RECORD were no longer on the treatment to which they had been randomized.
The study’s authors did note that the trial had less statistical power than initially planned because the overall occurrence of cardiovascular events was lower than anticipated. But according to the researchers, “It is good to have robust evidence that this useful medication does perform similarly to other glucose-lowering medications in regard of cardiovascular events… The data on fractures and heart failure are known class events, and here the study provides useful data to help clinicians and people with diabetes decide when it is not safe to use rosiglitazone.”
For more information, see the study’s abstract, or read “Combination Therapy For Type 2 Diabetes With Rosiglitazone (RECORD Study) Shows No Increase Of Cardiovascular Disease Or Death,” by Stephanie Brunner.