Treatment with human
recombinant growth hormone (GH) has yielded conflicting results in patients with
congestive heart failure. We analyzed the baseline somatotrophic axis in 50 patients with
dilated cardiomyopathy. Then, a double-blind, randomized, placebo-controlled study of GH was performed. We randomly allocated these patients to treatment with subcutaneous GH (2 IU daily) or placebo for a minimum of 12 weeks. The primary end-points were the effect on left ventricular (LV) mass and systolic wall stress. The secondary endpoint was LV ejection fraction. Severity of
heart failure as determined by cardiac index, LV end-diastolic diameter, and plasma
noradrenaline concentrations correlated markedly with baseline serum
insulin-like growth factor-1 (IGF-1) levels. Patients in the GH group had an increase in LV mass compared with the placebo group (p = 0.0001). There was no significant difference in LV systolic wall stress, mean blood pressure, or systemic vascular resistance between the two groups. New York Heart Association (NYHA) functional classification and distance in 6-minute walk test remained unchanged. The change in
IGF-1 concentrations between GH and placebo group was notably related (p = 0.0001) to the change in LV mass (p = 0.0001). The GH-induced increase of
IGF-1 predicted the changes of ejection fraction (p < 0.05). A marked increase of ejection fraction of 7% was observed in patients whose
IGF-1 increased by more than the median increase, in comparison to the patients with an increase below the median (p = 0.03). Serum levels of
IGF-1 reflecting GH secretion are diminished in relation to severity of
heart failure in patients with
dilated cardiomyopathy. GH-induced increases of
IGF-1 of more than 80 pg/mL caused notable improvement of ejection fraction. There is a marked increase in LV mass in patients with
dilated cardiomyopathy given GH. Changes in LV mass are related to changes in serum
IGF-1 concentrations.