Growth Hormone Withdrawal in Mid-Puberty: No Impact on Near Adult Height in Adolescents with Transient Idiopathic GHD

Context In children with idiopathic isolated growth hormone deficiency (IIGHD), GH secretion often normalizes by near adult height (NAH). Whether rhGH treatment can be safely discontinued earlier remains unclear. Objective To investigate if withdrawing rhGH treatment from mid-puberty onwards had no negative effect on attained NAH in adolescents who, after retesting, were no longer GH deficient. Design Prospective multicenter patient preference study (2017-2024) with follow-up until NAH (SEENEZ GH Study). Setting Pediatric endocrinology departments in multiple centers. Patients or Other Participants 127 adolescents (95 male, 75%) with childhood IIGHD (GH peak 1.7–10 µg/L) who tested GH sufficient (GH peak >6.7 µg/L) at mid-puberty. 44 continued rhGH (GHcont), 83 discontinued (GHstop). 99% of patients completed the study. Interventions RhGH treatment continuation vs discontinuation from mid-puberty until NAH. Main Outcome Measures Primary: NAH-SDS minus target height (TH)-SDS. Secondary: NAH-SDS, total pubertal growth (TPG), and predicted vs attained height gain. Results Mean (SD) NAH-SDS minus TH-SDS was -0.17 (0.60) in the GHcont and -0.18 (0.62) in the GHstop group (P=.96). Mean NAH-SDS was -0.91 (0.76) (GHcont) vs -0.78 (0.76) (GHstop) (P=.35). Mean (SD) TPG (from start of puberty) in males was 27.5 cm (7.0; GHcont) vs 25.9 cm (6.2; GHstop) (P =.25) and in females 20.5 cm (5.7; GHcont) vs 20.9 cm (7.6; GHstop) (P = .90). Predicted vs attained height gain based on the prediction model did not differ between groups. Conclusions In adolescents with transient IIGHD, rhGH treatment can be stopped at mid-puberty. These findings support reducing rhGH treatment duration, lowering patient burden and healthcare costs.