Metformin May Have Opposite Effect in Some Prediabetics

Metformin can cause an increase in glucose production in certain prediabetics.

Findings from a recent study suggest that metformin does not limit glucagon-stimulated glucose in the liver.

"In our clinical trial, metformin treatment appeared to trigger a compensatory increase of glucagon that may mitigate the ability of metformin to lower glucose production in prediabetic individuals and prevent the likelihood of hypoglycemia," said senior researcher K. Sreekumaran Nair, MD, PhD.

According to the study, published in Cell Reports, metformin is thought to limit the action of glucagon, the substances it is made of, or affect the level of enzymes used to make it. However, researchers in the study did not find this to be true for some patients.

Included in the study were 9 prediabetic patients taking metformin. Researchers observed that metformin decreased the liver’s production of glucagon in 6 patients with basal glucagon levels of less than 150 pg/mL.

In 3 patients with basal glucagon levels greater than 150 pg/mL, researchers found that metformin actually increased glucose production in the liver.

According to the study, previous preclinical metformin research used animal or cellular models to examine higher doses or used drugs in the same class as metformin, but are not approved for human use. Researchers state that this may be a cause for their differing results.

Researchers concluded that more research and a more diverse group of patients is needed to verify these results.