A medication that controls blood sugar levels may also protect the heart, based on a recent study that links metformin to reduced calcium build-up in men with prediabetes.
Published in the American Heart Association journal Circulation, this study looked at the long-term effects of metformin on the heart. Metformin is a common medication that helps control blood sugar levels in patients with type 2 diabetes. Studies suggest that metformin also helps high-risk patients prevent or delay the development of diabetes. Since diabetes is a major risk factor for heart disease, experts wondered if taking metformin for diabetes prevention also protects the heart.
To learn more, researchers analyzed data from the second phase of a trial called the Diabetes Prevention Program Outcomes Study.
Originally, this study assigned more than 3,200 patients with prediabetes to lifestyle changes, metformin or an inactive placebo pill for three years. After demonstrating the benefits of lifestyle changes and metformin, participants were then given the option to continue with these treatments, most of which did.
Ten years later, more than 2,200 of the original participants underwent imaging tests to measure calcium build-up in the arteries, called coronary artery calcium. Coronary artery calcium, often referred to as CAC, is an early sign of heart disease and is associated with increased risk for heart events.
The average age of participants was 64 at the start of the study, roughly 2/3 of which were women.
Overall, researchers found no difference in calcium build-up among participants assigned to the lifestyle and placebo group after ten years. However, men in the metformin group had significantly less coronary artery calcium than in the placebo group by the end of the study.
Authors also note that there was no association between metformin and coronary artery calcium in women—the reason for which remains unclear. Experts suspect that it may be due to the fact that women tend to have less plaque and calcium build-up than men.
Based on findings, authors conclude that metformin may prevent calcium build-up in men with prediabetes or early diabetes. The next step, according to authors, is to see whether reduced calcium build-up translates to fewer heart events in patients treated with metformin.