Commencing growth hormone replacement in adults with a fixed low dose. Effects on serum lipoproteins, glucose metabolism, body composition, and cardiovascular function

Abstract

The safety and effects of a fixed low dose of growth hormone (GH), 0.17 mg/day was evaluated for 3 months, on glucose metabolism, serum lipids, body composition and cardiac function in 53 GH deficient adults aged 18-78 years. Body composition was determined by dual energy X-ray absorptiometry and total body water was determined by bioelectrical impedance. Echocardiography was used to assess cardiac function and bicycle ergonometry was used to determine exercise capacity. All investigations were performed at baseline and after 3 months. At 3 months, serum levels of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3 and lipoprotein (a) and lean body mass were increased (P<0.05). Total and low density lipoprotein cholesterol levels and fat mass were reduced (P<0.05). There was an increase in the serum glucose value at 120 min after an oral glucose tolerance test performed at 3 months (P<0.05), no other changes in glucose metabolism or in cardiac function were noted. Side-effects were few and mild. This fixed low-dose regime resulted in improvements in body composition and lipid profile, without causing serious side effects. This is therefore a valid method to institute GH replacement in adults.