Issue 97 Item 1 ACC: Retrospective Study Indicates Glitazones Increase Risk For

Use of glitazones was associated with a 50 percent increase in risk of heart failure, according to a retrospective study. ATLANTA, GA — March 19, 2002 — A retrospective analysis of insurance claims data suggests that use of glitazones to manage type 2 diabetes may be associated with a significant increase in risk for heart failure.

Thomas Delea, PhD, of Policy Analysis, Brookline, Massachusetts, United States, presented these findings today at the American College of Cardiology (ACC) 51st Annual Scientific Session.

Using a database of healthcare insurance claims from 35 health insurers, which represent up to 17 million Americans, he studied claims filed from the period of January 1995 to March 2001. Dr. Delea identified 8,288 diabetics who were treated with one or more glitazone (troglitazone, rosiglitazone or pioglitazone) and 41,440 diabetic controls that didn’t use glitazones. Patients who were diagnosed with heart failure in the 12 months prior to the initial claim for a glitazone were excluded from the study.

The initial claim for a glitazone served as the index date. He then searched for claims indicating onset of heart failure. The average follow-up from index date was 8.5 months. During follow-up, the risk for heart failure was "4.5 percent among glitazone users and 2.6 percent in non-users", Dr. Delea said at a press briefing prior to presenting the study.

After adjusting for other potential confounders, the use of glitazones "was still associated with a 50 percent increase in risk of heart failure", he said.

Dr. John Buse, who heads a special committee on heart disease at the American Diabetes Association, said glitazones are useful medications but cautions that they need to be carefully monitored. He said most physicians are aware that the drugs are associated with both plasma volume expansion and edema. "The problem is that the people who need these drugs are the people who are already at the highest risk for heart failure."

Dr. Delea agreed and noted that in his study, glitazone users tended to be older, had diabetic complications, received insulin and had multiple risk factors for heart disease. "But nonetheless, there is a consistency of effect for glitazone," he said. "And the association between glitazone and heart failure is same across all subgroups."

Dr. Delea did caution that the findings are based on "observational data and need to be confirmed in a clinical trial".