EFFECT OF GROWTH-HORMONE ON CARDIAC-FUNCTION

At present, there is a growing body of evidence implicating growth hor mone (GH) and/or insulin-like growth factor-I (IGF-I) in the intricate cascade of events connected with the regulation of heart development and hypertrophy. In addition, advanced clinical manifestations of abno rmal GH levels almost always include impaired cardiac function, which may reduce life expectancy. This finding is related both to a primary impairment of heart structure and function and to metabolic changes su ch as hyperlipidaemia, increased body fat and premature atherosclerosi s. Acromegalic cardiomyopathy is better correlated with disease durati on than with CH or IGF-I levels. Myocardial hypertrophy with interstit ial fibrosis, lymphomononuclear infiltration and areas of monocyte nec rosis often result in increased right and left ventricular mass concen tric hypertrophy. Conversely, patients with childhood or adult-onset G M deficiency (GHD) have a reduced left ventricular mass (LVM) and ejec tion fraction (EF) and the indices of left ventricular systolic functi on remained markedly depressed during exercise. Cardiac function is re ported to improve during octreotide and GH replacement treatment in ac romegaly and CHD, respectively. The evidence that GH can increase card iac mass suggests its use in the treatment of idiopathic dilated cardi omyopathy. In a recent study on such patients, the administration of r ecombinant GH (rGH) was demonstrated to increase myocardial mass and r educe the size of the left ventricular chamber, resulting in improved haemodynamics, myocardial energy metabolism and clinical status.