Growth hormone and cardiac function

Impaired cardiovascular function, which may reduce life expectancy, has recently been demonstrated both in GH deficiency and excess. Moreover, experimental and clinical studies support the evidence implicating GH and/or IGF-I in the regulation of heart development. The existence of a specific acromegalic cardiomyophathy characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis which often result in biventricular concentric hypertrophy has been recently demonstrated. By contrast, patients with childhood or adulthood- onset GH deficiency (GHD) present with abnormalities of structure and function of the left ventricle. In these patients, a significant increase in the vascular intima-media thickness and an increased number of atheromatous plaques have also been reported. The abnormalities of cardiovascular system could be partially reverted by suppressing GH and IGF-I levels in acromegaly or after GH replacement therapy in GHD patients. The evidence that GH is able to increase cardiac mass suggested its use in the treatment of chronic heart failure of diverse etiologies. GH administration was demonstrated to induce an improvement in hemodynamics and clinical status in some patients. Although these data should be confirmed in double-blind placebo controlled studies in larger series, the promising results open new perspectives for GH treatment in humans.