Acromegalic Cardiomyopathy: An Entity on its own? The Effects of GH and IGF-I Excess and Treatment on Cardiovascular Risk Factors

Abstract

Acromegaly is a chronic disease resulting from constantly elevated concentrations of growth hormone (GH) and insulin-like growth factor I (IGF-I). If not adequately treated, GH and IGF-I excess is associated with various cardiovascular risk factors. These symptoms mainly include hypertension and impaired glucose metabolism, which can be observed in approximately one-third of patients. Other comorbidities are dyslipidemia and the presence of obstructive sleep apnea syndrome.

However, even in the absence of conventional cardiovascular risk factors, myocardial hypertrophy can occur, which reflects the impact of GH and IGF-I excess itself on the myocardium and is defined as acromegalic cardiomyopathy. Whereas previous echocardiography-based studies reported a high prevalence of cardiomyopathy, this prevalence is much lower in cardiac magnetic resonance imaging-based studies. Myocardial hypertrophy in acromegaly is due to a homogeneous increase in the intracellular myocardial mass and extracellular myocardial matrix and improves following successful treatment through intracellular changes. Intramyocardial water retention or ectopic lipid accumulation might not be of relevant concern.

Successful treatment significantly improves myocardial morphology, as well as cardiovascular risk factors. In addition to GH/IGF-I-lowering therapy, the diagnosis and treatment of cardiovascular complications is crucial for the successful management of acromegaly.