First-Line Diabetes Drug for Your Heart

Metformin for diabetes provides heart benefits over sulfonylureas

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Diabetes drugs can do wonders for patients' blood sugar. However, those drugs also come with some risks, particularly to the heart. A recent study compared the safety of the two most common diabetes drugs.

Diabetes patients taking sulfonylureas may have a higher risk of heart attack, stroke and death compared to patients taking metformin.

"Both drugs do a good job helping control diabetes and preventing nerve damage and eye disease associated with high sugar levels," said Marie R. Griffin, MD, MPH, of Vanderbilt University and senior author of the study.

"All medications have risks - talk to your pharmacist."

Recently, concerns were raised about another diabetes drug called Avandia (rosiglitazone), particularly about the heart risks associated with the drug.

In light of these concerns, Christianne L. Roumie, MD, MPH, of Vanderbilt University, and colleagues thought it was important to look at the cardiovascular effects of the two most commonly prescribed diabetes medications.

Smaller studies in the past have suggested that metformin offers heart-related benefits over other drugs. The study by Dr. Roumie and colleagues confirmed the advantage of metformin in a larger population.

"We demonstrated that for every 1,000 patients who are using metformin for a year there are two fewer heart attacks, strokes or deaths compared with patients who use sulfonylureas," said Dr. Roumie.

"I think this reinforces the recommendation that metformin should be used as the first medication to treat diabetes," she said.

Results from the study showed that rates of death and hospitalization for heart attack or stroke were 18.2 per 1,000 person-years among sulfonylurea users and 10.4 per 1,000 person-years among metformin users.

"We did this study because there was an important knowledge gap about whether metformin was superior to sulfonylureas for prevention of heart disease, stroke and death," said Dr. Griffin.

The study had a couple limitations. First, neither metformin patients nor sulfonylurea patients were compared to diabetes patients who did not take any oral medications. Second, the study population - which consisted entirely of veterans - was mainly men.

Metformin is already the first drug of choice for diabetes patients who need an oral medication to control their blood sugar. However, metformin has not been recommended for patients with kidney problems. For these patients, sulfonylureas may be the better option.

According to Dr. Roumie, this study's findings suggest that some patients taking sulfonylureas may benefit from switching to metformin.

Metformin is marketed under the brand names Fortamet, Glucophage, Glumetza and Riomet. Sulfonylureas are marketed under the brand names Diabeta, Glycron, Glynase, Micronase and Glucotrol.

The study included 253,690 patients starting diabetes treatment. Of these, 98,665 started sulfonylurea therapy and 155,025 started metformin therapy.

The research was funded by the Agency for Healthcare Research and Quality and the U.S. Department of Health and Human Services.

The study was published November 6 in the Annals of Internal Medicine.

Reviewed by: 
Review Date: 
November 8, 2012
Last Updated:
June 10, 2013