Cardiovascular Effects of Excess Growth Hormone: How Real is the Threat?

Abstract

Patients with acromegaly carry a high risk of developing cardiovascular diseases (CVD). In fact, CVD is the leading cause of mortality among this group of patients. The most frequent cardiovascular complications are heart failure (HF), valvular disease, hypertension, arrhythmias, and coronary artery disease (CAD). The pathophysiology centers on the family of growth hormone (GH). These hormones are involved in normal cardiac development and function; however, excess of insulin-like growth factor-1 (IGF-1), the principally active hormone, can also cause negative effects on the cardiovascular system. HF in acromegaly usually presents with biventricular enlargement and diastolic dysfunction and is strongly associated with the duration of GH excess rather than the degree of hormone elevation. There is a high prevalence of valvular disease affecting aortic and mitral valves among patients with longer disease duration. The development of hypertension in acromegaly may be attributed to the effects of chronic GH/IGF-1 excess on different organ systems, which act via several mechanisms. The aspect of arrhythmia and CAD complicating acromegaly are currently not fully understood.