THE EFFECT OF GROWTH-HORMONE REPLACEMENT THERAPY FOR UP TO 12 MONTHS ON LIPOPROTEIN COMPOSITION AND LIPOPROTEIN(A) IN GROWTH HORMONE-DEFICIENT ADULTS

The effect of growth hormone replacement therapy in near physiological doses on lipoprotein composition and serum lipoprotein(a) concentrati ons was investigated in growth hormone-deficient subjects. A randomise d, double-blind, placebo-controlled trial of recombinant growth hormon e was undertaken for 6 months followed by an open extension for a furt her 6 months (0.125 IU/kg per week for the first 4 weeks of each 6 mon th period and thereafter 0.25 IU/kg per week). A total of 18 patients with isolated growth hormone deficiency or hypopituitarism were studie d. Lipid concentrations were estimated in lipoprotein fractions and pr otein concentrations were measured in low density lipoprotein (LDL). G lucose and glycated haemoglobin in blood and insulin, cholesterol, tri glyceride, apolipoproteins A-I and B and lipoprotein(a) concentrations were measured in serum. In the placebo-controlled phase fasting brood glucose concentrations increased with growth hormone treatment from 5 .0 +/- 0.2 to 5.8 +/- 0.2 mmol/l (P = 0.02) (mean +/- S.E.M.), althoug h no significant changes were seen in lipids or lipoproteins. In the g roup receiving active treatment total serum cholesterol decreased from 6.0 +/- 0.4 to 5.2 +/- 0.3 mmol/l (P = 0.002) after 6 months, due to reduced LDL cholesterol concentrations. Low density lipoprotein protei n concentrations fell (0.8 +/- 0.1 Versus 0.7 +/- 0.1 g/l) (P = 0.005) , and LDL phospholipid levels decreased from 0.9 +/- 0.1 to 0.7 +/- 0. 1 mmol/l (P = 0.007). Serum cholesterol and LDL composition reverted t o pre-treatment Values by 12 months. Fasting blood glucose remained ab ove pre-treatment values (P = 0.036) and fasting insulin was significa ntly increased (P = 0.044). There was no effect of growth hormone ther apy on serum triglyceride, apolipoprotein or lipoprotein(a) concentrat ions. In conclusion, growth hormone therapy with near physiological do ses has no long term effects on serum lipoprotein(a) concentrations or lipoprotein composition. (C) 1997 Elsevier Science Ireland Ltd.