Metabolic Profile in Growth Hormone-Deficient (GHD) Adults after Long-Term Recombinant Human Growth Hormone (rhGH) Therapy

Abstract

The metabolic effects of recombinant human GH (rhGH) therapy in adults are well-documented in the short term. The effects of long-term rhGH therapy beyond 5 yr on metabolic parameters are presently unknown. The aim of the study was to evaluate the long-term effects of rhGH treatment on biochemical and anthropometric parameters in a large cohort of GH-deficient adults. Ninety-eight GH-deficient adult patients treated with rhGH for at least 10 yr were included (mean age, 59.4 yr; 50% female). Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, anthropometric parameters, IGF-I, and glucose were evaluated at baseline and after 5, 10, and 15 yr of treatment. In addition, the prevalence of the metabolic syndrome (MS) and the incidence of cardiovascular events were assessed. Total cholesterol and low-density lipoprotein cholesterol concentrations were lower, and high-density lipoprotein cholesterol levels were significantly higher during long-term rhGH replacement when compared to baseline (all P < 0.001). Both waist circumference (P < 0.001) and body mass index (P = 0.018) were significantly higher after 10 yr, as were fasting plasma glucose levels (P < 0.001). No significant changes were observed in triglycerides, waist-to-hip ratio, and blood pressure during follow-up. In the subset of patients with 15-yr rhGH treatment (n = 43), generally similar metabolic effects were found. MS prevalence was increased after 10 yr of rhGH treatment (57.1 vs. 32.7%; P < 0.001), especially in males (69.4 vs. 32.7%; P < 0.001). Despite improvement of several cardiovascular risk factors, MS prevalence increased significantly during rhGH treatment. The effect of long-term rhGH treatment on overall cardiovascular risk profile needs to be established in a larger cohort.