Analysis of short- and long-term metabolic effects of growth hormone replacement therapy in adult patients with craniopharyngioma and non-functioning pituitary adenoma

Purpose: Adult patients operated for craniopharyngioma develop more frequently GH deficiency (GHD) than patients operated for non-functioning pituitary adenoma (NFPA). The aim of the study was to compare both short- (1 year) and long-term (5 years) effects of rhGH in 38 GHD adult patients (19 operated for Craniopharyngioma (CP) and 19 for NFPA). Methods: IGF-I levels, body composition (BF %), BMI, lipid profile and glucose homeostasis were evaluated in all patients. Pituitary MRI was performed at baseline and during follow-up, as needed. Results: At baseline no difference between the two groups was observed, apart from a higher prevalence of diabetes insipidus in CP patients (79 vs 21 %). After 12 months, IGF-I SDS normalized and BF % significantly decreased only in the NFPA group. During long-term treatment, decrease in BF % and improvement in lipid profile shown by reduction in total- and LDL-cholesterol were present in NFPA group only, while increase in insulin levels and HbA1c and decrease of QUICKI were observed in CP patients only. Accordingly, after long-term therapy, the prevalence of metabolic syndrome (MS) was significantly higher in CP than in NFPA group (37 % in CP and in 5 % in NFPA group; p <0.05). Conclusion: The present data suggest that CP patients are less sensitive to the positive rhGH effects on lipid profile and BF % and more prone to insulin sensitivity worsening than NFPA patients, resulting in increased prevalence of MS in CP only.