Growth Hormone Therapy in Heart Failure: Where Are We Now?

Catherine Demers, MD, MSc, Robert S. McKelvie, MD, PhD

Disclosures

CHF. 2003;9(2) 

In This Article

The Cardiovascular System in States of GH Deficiency and Excess

Studies in patients with GH deficiency have provided further knowledge of the interaction between GH and the cardiovascular system. Patients with GH deficiency present with decreased left ventricular wall thickness, left ventricular dilatation, increased left ventricular systolic wall stress, decreased exercise capacity, and decreased skeletal muscle mass and strength.[18,19,20,21,22,23] Administration of GH to these patients improves cardiac volumes and skeletal muscle mass, with resulting improvements in muscle strength as well as exercise performance.[21,24] In patients with GH deficiency presenting with HF due to dilated cardiomyopathy and unresponsive to digitalis, diuretics, and vasodilators, GH therapy administered for several months led to marked improvements in cardiac dimension, left ventricular ejection fraction, and symptoms.[22,25] These changes suggest that GH not only plays an important role in the development and growth of the human myocardium but also maintains normal left ventricular size and function in adults, with improvement in skeletal muscle mass and strength.

In contrast, acromegaly, the clinical manifestation of prolonged GH excess, is associated with concentric biventricular hypertrophy, hypertension, increased incidence of congestive heart failure, and increased mortality.[10] Cardiac changes associated with acromegaly include increased left and right ventricular mass -- the degree of hypertrophy related to duration of disease rather than circulating levels of GH and IGF-I -- and preserved systolic function with associated diastolic dysfunction.[10] The cardiac manifestations of sustained GH levels lead to nonfunctional hypertrophy with associated interstitial fibrosis. The potential role of physiologic replacement of GH in patients with GH deficiency with associated dilated cardiomyopathy, left ventricular chamber dilatation, and increased wall stress provides some rationale to evaluate the use of GH in the treatment of patients with HF. Proper dosage and length of GH administration is of great importance due to the deleterious effect of prolonged supraphysiologic levels observed in acromegaly, and we should be alerted to early signs of GH excess.

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