Evaluation of Permanent Growth Hormone Deficiency (GHD) in Young Adults with Childhood Onset GHD: A multicenter study

Background: Reconfirming the diagnosis of childhood onset growth hormone deficiency (GHD) in young adults is necessary to demonstrate the need for continuation of GH therapy. Objective: This nationally−based study was planned to establish GH status during adulthood in childhood−onset GH deficient patients and to evaluate factors that would predict persistency of the GHD. Methods: In this multicenter study, 70 GH deficient patients who had reached final height were evaluated after completion of GH treatment. Fifty−two patients (74%) had isolated GHD and 18 patients (26%) had multiple pituitary hormone deficiency (MPHD). Patients who had reached final height and the pubertal Tanner stage 5 were reevaluated for GH status. After at least 6 weeks of cessation of GH treatment, patients were retested with insulin induced hypoglycemia. Results: GHD was found to be transient in 64.3% of all patients. Of the isolated GH deficient patients 82.7% had transient GHD, whereas 88.9% of the MPHD patients showed persistent GHD. Comparison of isolated GH deficient and multiple hormone deficient patients indicated higher peak GH, IGF−I and IGFBP−3 levels in isolated GH deficient patients. No parameter was significantly different in the transiently and persistently GH deficient patients with respect to gender. Although specificity of IGF−I value of less than −2 SD showing persistency of GHD was lower than the specificity of IGFBP−3 value of less than −2 SD (65.7% vs 84%), negative predictive values were similar for the two parameters (85.2% and 84%, respectively). Conclusion: Most of the cases of childhood onset GHD are idiopathic and the GHD is transient. In patients with MPHD, GHD is generally permanent. Low IGF−I and IGFBP−3 levels are supporting findings to show persistency of the GHD. Conflict of interest:None declared.