The evaluation of medical treatment efficacy will be based on the analysis of changes in anthropometric indexes, IGF-I levels, liver function test, body composition assessed by DEXA Total Body and bioimpedance analysis, liver ultrasounds. At 3 and 6 months, the patients of both subgroups A and B will be clinically re-evaluated, plasma samples for metabolic, liver function tests, and endocrine profile will be obtained, body composition and liver ultrasounds will be determined. At the end of the 6-months period of treatment and observation, the GH response to a subsequent GHRH + Arginine will be re-tested to confirm or to exclude GHD. All the patients with persistent GHD will continue recombinant GH therapy.