Clinical potential of growth hormone in the treatment of congestive heart failure.
Substantial evidence supports a role for the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis in regulation of normal cardiac growth, structure and function. Moreover, experimental data suggest beneficial effects of GH and IGF-1 on contractility and peripheral resistance in rats with impaired cardiac function. An increased Ca(++) responsiveness is one possible underlying cause for the improvement in contractility, although effects of GH and IGF-1 on apoptosis may also play a more long term role for cardiomyocyte survival. Until recently, studies regarding GH treatment in heart failure were limited to case reports where administration dramatically improved cardiac function. In a small non-blind study of 7 patients with idiopathic dilated cardiomyopathy and congestive heart failure (CHF) without GH deficiency who received treatment with recombinant GH (somatropin) for 3 months, considerable improvement of cardiac function was reported. More recent studies have demonstrated beneficial effects in patients with CHF due to both ischaemic and idiopathic dilated cardiomyopathy, with improvements in haemodynamics when somatropin was added both as a maintenance therapy and as a short term infusion. So far, 2 placebo-controlled studies with somatropin as adjunctive therapy in patients with CHF have been reported, although neither study could confirm previously reported improvement in systolic function and lowering of wall stress. In summary, it is clear that further placebo-controlled clinical trials are mandatory to verify positive effects and to monitor long term safety when somatropin is administered as an agent in the treatment of CHF.
Isgaard
J
J
Research Center for Endocrinology and Metabolism, Göteborg, Sweden. jorgen.isgaard@ss.gu.se
Bergh
C H
CH