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 recombinant human GH (rhGH) treatment can be safely discontinued earlier remains unclear. Objective This work aimed to investigate if withdrawing rhGH treatment from mid-puberty onward had no negative effect on attained NAH in adolescents who, after retesting, were no longer GH deficient. Methods A prospective multicenter patient preference study was conducted at pediatric endocrinology departments in multiple centers (2017-2024) with follow-up until NAH (SEENEZ GH Study). Participants included 127 adolescents (95 male, 75%) with childhood IIGHD (GH peak 1.7-10 mu g/L) who tested GH sufficient (GH peak >6.7 mu g/L) at mid-puberty. Forty-four continued rhGH (GHcont), 83 discontinued (GHstop). A total of 99% of patients completed the study. Intervention included rhGH treatment continuation vs discontinuation from mid-puberty until NAH. The primary outcome measure was NAH-SDS minus target height (TH)-SDS. The secondary outcome was 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 health-care costs.