CHICAGO, Illinois — The results of meta-analysis presented this week at the American Diabetes Association (ADA) 2013 Scientific Sessions adds new heft to earlier observations that metformin is associated with a reduction in the risk of cardiovascular events while rosiglitazone (Avandia, GlaxoSmithKline) increases the risk, including the risk of heart failure and MI.
Dr Peter Boyle (International Prevention Research Institute, Lyon, France), the lead researcher of the DIABAMON project, a study investigating the safety of glucose-lowering medications, said that while there have been significant reductions in the risk of cardiovascular mortality since the 1950s, the reduction in the risk of coronary disease among patients with diabetes hasn't been quite as dramatic. The group decided to investigate the risks of the drugs, given the controversy surrounding rosiglitazone.
In 29 different studies, metformin was associated with a 10% reduction in the risk of cardiovascular events, with the drug associated with a 10% reduction in the risk of heart failure in seven studies and a 12% reduction in the risk of MI in nine studies. In contrast, rosiglitazone was associated with a 21% increased risk of cardiovascular events in 25 studies, a 27% increased risk of heart failure in 13 studies, and a 17% increased risk of MI in 21 studies.
The findings with pioglitazone, however, were less clear, said Boyle. The meta-analysis revealed a 9% reduction in the risk of cardiovascular events and a 10% reduction in the risk of MI, but no relationship with heart failure.
Boyle cautioned, however, that the medical community has not paid enough attention to the comparator arm in the studies, particularly in meta-analyses that group large numbers of disparate trials and patients together. For example, at least one study compared rosiglitazone with metformin, a drug that reduces the risk of cardiovascular events, and this would affect the relative risks of cardiovascular events observed in that particular trial.
Overall, Boyle told an assembled ADA audience that the results were positive. The finding of a reduction in risk with metformin is encouraging, and the outlook for patients with diabetes is getting a little bit better, he said.
Heartwire from Medscape © 2013 Medscape, LLC
Cite this: CVD Reduced With Metformin, Higher With Rosiglitazone: Meta-Analysis - Medscape - Jun 24, 2013.