Acarbose May Equal Metformin for Diabetes Control

The oral diabetes medicine acarbose (Precose) may be as effective at controlling blood glucose levels as metformin, according to a study recently published in the medical journal The Lancet Diabetes & Endocrinology. Metformin is the most commonly used diabetes drug in the world, with more than 61 million prescriptions for the medicine filled in the United States alone in 2012.

To determine how the alpha-glucosidase inhibitor acarbose and metformin compare in controlling diabetes in an Asian population, researchers at 11 sites in China recruited people with newly diagnosed Type 2 diabetes, ages 30 to 70, who had not been treated with diabetes medicine or who had been treated for no more than a month. Eligible participants had an HbA1c (a marker of glucose control over the previous 2–3 months) of 7% to 10%, a fasting plasma glucose level less than or equal to 200 mg/dl, and a body-mass index (a measure of weight relative to height) of 19 to 30. Enrollees were randomly assigned to receive either acarbose or metformin for 48 weeks.


Over the course of the trial period, 16% of those in the acarbose group and 20% of those in the metformin group discontinued treatment, with a total of 784 people being included in the final analysis. The researchers found that people in the acarbose group had an average HbA1c reduction of 1.11%, compared to an average reduction of 1.12% in the metformin group. Participants in the two groups also experienced identical rates of hypoglycemia (low blood glucose) and serious adverse events. Results did not differ based on body weight, body-mass index, or the dietary percentage of carbohydrate.

“This study is the first head-to-head comparison of metformin and acarbose as initial therapy for Type 2 diabetes after failure of therapeutic lifestyle modification,” according to the researchers. “Metformin should remain as first-line treatment for patients with newly diagnosed Type 2 diabetes, while patients with exaggerated postprandial excursion [high after-meal glucose levels] can be treated with an alpha-glucosidase inhibitor as an alternative therapy before cardiovascular benefits of acarbose are validated and confirmed in ongoing studies.”

Limitations of the study include the absence of a placebo (inactive treatment) control group and the lack of an assessment of gut hormones that could be affected by the two medicines. The authors call for further research comparing acarbose, as well as newer diabetes medicines, to metformin.

For more information, read the article “Acarbose Cuts HbA1c on Par With Metformin,” or see the study’s abstract in The Lancet Diabetes & Endocrinology. And to learn more about metformin or acarbose, click here or here, respectively.