Metformin Outperforms Common Class of Diabetes Drugs in Study
Researchers analyzed data from nearly 24,000 patients with type 2 diabetes, average age 62, who were treated with one of three drugs called sulfonylureas (glipizide, glyburide, and glimepiride) or with another type of drug called metformin.
Sulfonylureas help decrease blood sugar levels by stimulating the pancreas to produce insulin. Metformin also helps reduce blood sugar levels.
Overall, all three sulfonylureas were associated with a more than 50 percent greater risk of death compared to metformin, according to the study, which was funded by drug company Astra Zeneca.
The researchers also found that, among diabetes patients with heart disease, glipizide was associated with a 41 percent greater risk of death and glyburide was associated with a 38 percent greater risk of death, compared with glimepiride and metformin.
According to one expert not connected to the study, the new data could provide some guidance for patients.
"Patients taking sulfonylureas should be made aware of this increased risk of death and other oral options for glycemic [blood sugar] control should be discussed," said Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City.
The study was to be presented Sunday at The Endocrine Society's annual meeting in Houston.
"We have clearly demonstrated that metformin is associated with a substantial reduction in mortality risk, and, thus, should be the preferred first-line agent, if one has a choice between metformin and a sulfonylurea," said study author Dr. Kevin M. Pantalone, an endocrinologist at Summa Western Reserve Hospital in Cuyahoga Falls, Ohio.
He conducted the study with a team of researchers from Cleveland Clinic.
Another expert said the study may have "enormous clinical implications."
Dr. Minisha Sood, also an endocrinologist at Lenox Hill, said that sulfonylureas may fare worse than metformin because the former might "interfere" with cardiovascular processes that strengthen and protect heart tissue so it becomes more resilient should a cardiac event occur.
"What's interesting about this study is that all three sulfonylureas examined led to increased mortality rates vs. metformin in the entire cohort study, which included patients without coronary artery disease," Sood added. "Does this mean that we shouldn't be prescribing sulfonylureas at all? I think prospective trials are needed to answer that question, so the jury is still out."
Nearly 26 million people in the United States have diabetes, according to the U.S. Centers for Disease Control and Prevention. Many of these patients also have other health problems, including heart disease.
Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about diabetes medicines.
Posted: June 2012