Endocrine Abstracts

Aim of this study was to evaluate the impact of rhGH treatment on glucose and lipid metabolism in in 26 patients (17M and 9F, age 47.0±11.1 years) with adult onset GH deficiency. Metabolic parameters (fasting glucose and insulin, glycated haemoglobin, lipid profile, body composition, OGTT) and indices of insulin resistance (IR) and sensitivity (IS), i.e. homeostasis model assessment (HOMA-IR and derived ISI-HOMA), quantitative insulin check index (QUICKI), ISI-composite, insulinogenic index (IGI) and area under the curve (AUC) for glucose and insulin derived from OGTT, were evaluated at baseline, after 1 (n=26) and 3 years (n=15) of rhGH therapy (GH dose: 0.3±0.2 mg/day). At baseline, all patients had low IGF-I levels, high BMI and percent of body fat. Two out of 26 patients had impaired glucose tolerance (IGT). After 1 year, IGF-I normalization, BF% reduction and lean mass increase occurred (P<0.005) and persisted after 3-years treatment. Fasting insulin, glycated haemoglobin, total cholesterol, triglycerides, HOMA-IR, QUICKI, ISI-HOMA, AUC for insulin, IGI and ISI-composite did not differ after 1 and 3 years from baseline, while glucose and LDL-cholesterol levels had a transient increase and reduction after 1 year, respectively. After 3 years HDL-cholesterol levels increased (P<0.05) and basal insulin secretion (HOMA-B%) decreased (P<0.05). AUC for glucose significantly increased after 1 and 3 years of treatment (P<0.02). One patients progressed to diabetes after 1 year, while 5 showed IGT after 3 years. In conclusion, rhGH therapy improves body composition and lipid profile, but causes a small transient increase in fasting glucose. Since deterioration of glucose tolerance, as indicated by increase in AUC for glucose and development of IGT, a strict monitoring of glucose metabolism during long-term GH replacement therapy should be performed.