diabetic cardiomyopathy

Diabetes can damage the heart in obvious ways — by speeding up coronary artery disease — but it can also harm the heart muscle directly. Diabetic cardiomyopathy is heart-muscle dysfunction attributable to diabetes itself, occurring even when the coronary arteries are not significantly blocked and blood pressure and valves are normal. In other words, the sugar-related disease, not clogged arteries, is the culprit.

Chronically high blood sugar and the metabolic disturbances of diabetes are thought to stiffen and scar the heart muscle, alter how it uses energy, and impair the tiny blood vessels within it. Early on, the most typical problem is impaired relaxation — the ventricle becomes stiff and fills poorly (diastolic dysfunction) — which can progress toward heart failure with preserved ejection fraction; in some, contraction also weakens over time.

Because it often develops silently and overlaps with the coronary disease, high blood pressure, and obesity that frequently accompany diabetes, it can be hard to isolate as a single diagnosis, and the concept is partly one of exclusion. Management centres on good blood-sugar and blood-pressure control, weight and lifestyle measures, and certain diabetes medications (such as SGLT2 inhibitors) that have been shown to benefit the heart.