How does diabetes harm the heart?

Diabetes is hard on the heart, increasing the risk for heart failure by two to three times in men and up to five times in women.

Previous research has implicated high levels of insulin, a hallmark of Type 2 diabetes, as a key factor in heart failure associated with diabetes.

A research team led by E. Dale Abel, MD, PhD, professor and department executive officer of internal medicine in the University of Iowa Carver College of Medicine and director of the Fraternal Order of Eagles Diabetes Research Center at the UI, has now shown that too much insulin in the blood (hyperinsulinemia) contributes to heart failure by triggering a molecular chain reaction that damages heart muscle cells.

Blocking this insulin signaling pathway in heart muscle—with the beta blocker drug carvedilol or the antidepressant paroxetine (Paxil)—reverses some of the heart damage and improves heart function in diabetic mice, even without altering metabolic problems such as high blood sugar and high insulin. The findings, published in the journal Circulation, suggest these drugs might have potential for preventing or treating heart failure associated with Type 2 diabetes.