A recent study has come to the conclusion that three common diabetes medications are associated with a higher incidence of death.

Glipizide, glyburide, and glimepiride, known collectively as sulfonylureas, stimulate the pancreas to produce insulin, which helps decrease blood-sugar levels. They are used primarily by Type 2 diabetes patients. In the past, these medications were considered comparable with one another in terms of safety and effectiveness, but that has been called into question recently. A study compared them to another type of blood-sugar-reducing drug, metformin, spurred by recent findings that some sulfonylureas may be safer than others.

Researchers found that all three sulfonylureas increased the risk for death by 50 percent when compared to metformin. Furthermore, in patients with underlying heart conditions, only glimepiride did not increase the risk for death compared to metformin. Glipizide raised the risk by 41 percent, and glyburide was associated with a 38 percent increase.

This spells bad news for diabetics considering many have cardiovascular disease. While sulfonylureas may not be an option for some diabetics metformin is also available as a generic.

In the United States, 18 million people, or about 5.5 percent of the population, have diabetes, with approximately 7 million additional undiagnosed cases. Many of those people also face other health conditions, like heart disease, high blood pressure, and blindness. The American Diabetes Association believes that as many as 79 million Americans are considered to be “prediabetes,” with blood glucose levels that are higher than average, but are not high enough to be classified as diabetes.

Aside from sulfonylureas and metformin, there are also meglitinides, thiazolidinediones, DPP-4 inhibitors, and alpha-glucosidase inhibitors, which can be used separately or in conjunction with other anti-diabetes medications. All, of course, come with their own usage instructions and potential side effects.

The results of this investigation were presented at The Endocrine Society's 94th Annual Meeting in Houston and should be considered preliminary until published in a peer-reviewed journal.