Diabetes Drugs: Some Work Better Than Others

Not all diabetes drugs are equally effective at preventing death and heart disease over a decade-long period, a new study suggests.

Diabetes patients who take some versions of drugs called insulin secretagogues are 20 to 33 percent more likely to die from any cause over a 10-year period than patients who take the diabetes drug metformin, the study said.

Insulin secretagogues have been around since the 1950s and work by stimulating cells to produce insulin, while metformin works by reducing excess sugar seen in Type 2 diabetes.

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But the findings do not suggest that insulin secretagogues are harmful to people only that some seem to be less effective than metformin , said study researcher Dr. Tina Ken Schramm, a senior resident at the Heart Center at Rigshospitalet Copenhagen University Hospital in Denmark.

Metformin is doctors' first choice for treating Type 2 diabetes, Schramm said. But the drug "is contraindicated in patients with renal failure, severe heart failure and when patients are intolerant to metformin," she told MyHealthNewsDaily, which explains why not all diabetes patients can take metformin.

The study was published today (April 6) in the European Heart Journal.

The drugs' effects

Schramm and her colleagues examined the health status of 107,806 Danish people ages 20 and older who were being treated with insulin secretagogues or metformin between 1997 and 2006. More than half the people in the study were on insulin secretagogues.

Researchers found that people who took the insulin secretagogues glimepiride, glyburide, gliclazide and tolbutamide had a greater risk of having a heart attack or stroke or dying from any cause during the 10-year period, compared with those who took only metformin.

Also, for patients who have had a heart attack before, those who took certain insulin secretagogues were 33 to 50 percent more likely to die from any cause than those on metformin, according to the study.

But the insulin secretagogues gliclazide and repaglinide were equally effective as metformin at preventing death from all causes, researchers said. However, gliclazide was associated with an increased risk of stroke, compared with metformin therapy, in diabetes patients who had had a heart attack.

Wide appeal

Diabetes affects 8.3 percent of the U.S. population, and 26.9 percent of U.S. residents older than 65, according to the National Institutes of Health. The disorder causes heart disease, stroke, kidney failure and blindness, and it is the seventh-leading cause of death in the United States.

Fifty-eight percent of people with diabetes take an oral medication, like metformin and insulin secretagogues, to control the amount of glucose in their blood, according to the NIH.

Most doctors already know to recommend metformin as a first-line treatment for diabetes, but this study provides one of the largest observations of the effectiveness of metformin compared with other commonly used diabetes drugs , said Dr. Darren McGuire, an associate professor of cardiology at the University of Texas Southwestern Medical Center at Dallas, who was not involved with the study.

Insulin secretagogues are commonly used among diabetes patients because their glucose-lowering effects are potent, they're well-tolerated by most patients and they come in a generic form, making them cheaper than some other medications, McGuire said. However, they also carry risks of low blood sugar and can cause weight gain.

It's not completely clear why metformin seems to be better for the heart than insulin secretagogues, he said, especially because metformin is one of the least potent diabetes drugs for treating high blood sugar.

But metformin's positive heart effects "may be due to avoidance of hypoglycemia (low blood sugar) that can have adverse cardiovascular consequences," McGuire told MyHealthNewsDaily.

Pass it on: Metformin works better than some insulin secretagogues for preventing death, heart attack and stroke in diabetes patients.

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Follow MyHealthNewsDaily staff writer Amanda Chan on Twitter @AmandaLChan.