Diabetes drugs and heart health: men and women have different outcomes

Popular diabetes drugs have different effects on cardiovascular health in men and women, according to a new study from Washington University School of Medicine in St. Louis.

Even though medications like metformin and rosiglitazone seem to help control blood sugar levels equally for males and females, the differences in heart-related effects surprised researchers.

"We saw dramatic sex differences in how the heart responds to the different therapies," said senior author Robert J. Gropler, M.D., professor of radiology. "Our study suggests that we need to better define which therapies are optimal for women with diabetes and which ones are optimal for men."

The study

Investigators recruited 78 patients who were assigned to one of three groups: a group that received metformin alone, a group that received metformin plus rosiglitazone, or a group that received metformin plus Lovaza – a type of fish oil.

When comparing the three groups without separating men and women, the researchers didn't see differences in heart metabolism. But when the participants were grouped by gender, the drugs showed very different effects on the heart – even while blood sugar remained balanced in all patients.

"The most dramatic difference between men and women is with metformin alone," said Gropler. "Our data show it to have a favorable effect on cardiac metabolism in women and an unfavorable one in men."

Men who took either rosiglitazone or Lovaza with metformin seemed to experience fewer negative heart effects, while women improved heart metabolism further when taking metformin plus rosiglitazone.

Burning fat

Gropler said that previous research shows men and women differ in the way their hearts burn fuel – males tend to burn more glucose, while women burn more fat. This explains why women with diabetes may have a higher instance of aggressive heart failure than men – their hearts are burning more fats.

"We now know there are sex differences at baseline, both in the metabolism of healthy hearts and in the hearts of patients with diabetes," Gropler concluded. "We are adding the message that these sex differences persist in how patients respond to drugs. For patients with diabetes, we are going to have to be more attentive to sex differences when we design therapies."

The study was published in the December issue of the American Journal of Physiology – Heart and Circulatory Physiology.

Source: Washington University School of Medicine