The effects of GH replacement therapy on cardiac morphology and function, exercise capacity and serum lipids in...

To assess effects of GH replacement therapy on cardiac structure and function, exercise capacity as well as serum lipids in elderly patients with GH deficiency (GHD).

Thirty-one patients (six females, 25 males), aged 60-79 years (mean 68 years) with GHD on stable cortisone and thyroxine substitution were studied. All men with gonadotropin deficiency had testosterone and one woman had oestrogen replacement. They were randomized in a double-blind manner to GH or placebo treatment for 6 months, followed by another 12 months GH (Humatrope, Eli Lilly & Co, Uppsala, Sweden). GH dose was 0.017 mg/kg/week for 1 month and then 0.033 mg/kg/week divided into daily subcutaneous injections at bedtime. Echocardiography, exercise capacity tests and serum lipid measurements were performed at 0, 6, 12 and 18 months.

During the 6-month placebo-controlled period there were no significant changes in the placebo group, but in the GH-treated group there was a significant increase in IGF-I to normal levels for age, with median IGF-I from 6.9 to 18.5 nmol/l, increase in resting heart rate and maximal working capacity. During the open GH study, IGF-I increased from 8.7 to 19.2 nmol/l at 6 months and 18.8 nmol/l at 12 months (P

GH substitution to elderly patients with GHD caused only a transient increase in heart rate. At the end of the 12 months there were no significant changes on cardiac noninvasive structural and functional parameters. Maximal working capacity transiently improved. Thus, the therapy was safe without negative effects on cardiac structural and functional noninvasive parameters. Lipid profiles improved with reduction of serum LDL cholesterol accompanied by significant improvement of LDL/HDL ratio and serum HDL cholesterol after 12 months treatment.