Effect of Short-term Therapy with Recombinant Human Growth Hormone (GH) on Metabolic Parameters and Preclinical Atherosclerotic Markers in Hypopituitary Patients with Growth Hormone Deficiency

Abstract

This study examines the effects of growth hormone replacement on body composition, insulin sensitivity, lipid profile, endothelial dysfunction and carotid intima media thickness in patients with adult-onset growth-hormone (GH) deficiency. Twelve patients with severe GH deficiency received GH replacement for one year. In all patients, the following parameters were evaluated before and after six and twelve months of therapy: fasting glucose, insulin levels and lipid profile, bone mineral density and body composition. Carotid intima media thickness and brachial flow-mediated dilatation were also evaluated by arterial ultrasonography at basal condition and after one year of therapy. No significant changes were seen in body weight and blood pressure, total fat and lean mass, or bone mineral density after six months of GH replacement. There was an increase in triglycerides (p = 0.05), while total and HDL cholesterol, blood glucose, insulin levels did not change significantly. After twelve months, an increase in lean mass and a decrease in fat mass (p < 0.01 vs. baseline), a decrease in insulin resistance (p < 0.01 vs. six months; p = 0.01 vs. baseline) and a decrease in triglycerides (p < 0.01) were observed. Intima media thickness was greater in GH deficiency than in controls (p = 0.01) before therapy, and was unchanged after twelve months of therapy, whereas the flow-mediated dilatation tended to improve (p = 0.05). GH replacement is able to reverse typical metabolic and body composition alterations in patients with adult GH deficiency after twelve months, but it is unable to revert the vascular alteration completely. Flow-mediated dilatation seems to be a more precocious marker of the remission of arterial damage.