Growth Hormone (GH) Secretion in Patients with Childhood-Onset GH Deficiency: Retesting after One Year of Therapy and at Final Height

Background: Recent studies have shown that many patients treated with growth hormone (GH) during childhood because of idiopathic GH deficiency (GHD) are no longer GH deficient when retested after cessation of GH therapy when final height is achieved. These patients are labelled as transient GHD. We hypothesized that normalization of GH secretion in transient GHD could occur earlier during the course of GH treatment, which could allow earlier cessation of GH treatment. Methods: In a retrospective study, GH secretion was re-evaluated after cessation of GH treatment at final height in 43 patients diagnosed during childhood as idiopathic GHD (10 with multiple pituitary hormonal deficiencies (MPHD) and 33 with isolated GHD (IsGHD)). In a prospective study, GH secretion was re-assessed after interruption of GH treatment given for 1 year in 18 children with idiopathic GHD (2 MPHD, 16 IsGHD). GH secretion was evaluated by glucagon or insulin stimulation tests. Results: In the retrospective study, all the 10 patients with MPHD and 64% of the 33 patients with IsGHD were still deficient at re-evaluation using the paediatric criteria to define GHD (GH peak