SAT-189 Combined Human Growth Hormone and Gonadotropin-Releasing Hormone Analog Therapy improves pubertal growth in children with poor final height prognosis: A Retrospective Observational Study

Abstract Disclosure: I. Flechtner: None. P. Olivier: None. M. Jesuran-Perelroizen: None. M. Viaud: None. G. Pinto: None. D. Samara-Boustani: None. C. Thalassinos: None. D. Kariyawasam: None. M. Polak: None. A. Stoupa: None. Introduction: Growth hormone (GH) therapy is well-established in increasing growth velocity and adult height for specific indications. In cases where final height prognosis remains insufficient despite normal puberty onset, clinicians may combine GH with gonadotropin-releasing hormone analogs (GRHa) to delay epiphyseal maturation. However, evidence supporting the efficacy of this combined therapy remains limited.Objective: To assess, in patients with growth hormone deficiency (GHD) or small for gestational age (SGA), whether the addition of GRHa to GH treatment in children with poor final height prognosis improves growth outcomes compared to GH alone.Materials and Methods: This retrospective, observational cohort study was conducted across three centers. Children with poor height prognosis at puberty onset received at least 12 months of combined GH and GRHa therapy. Growth outcomes, including final height (FH), predicted adult height (PAH), and growth velocity, were compared between the GH+GRHa and GH-alone groups. Heights were expressed in standard deviation scores (SDS). Subgroup analyses were conducted based on the underlying condition (i.e., GHD or SGA).Results: A total of 131 patients were included: 64 treated with GH+GRHa (51% girls) and 67 treated with GH-only (43% girls). At puberty onset (Tanner stage 2), patients in the GH+GRHa group were younger (11.3 ± 1.1 years vs 12.4 ± 1.2 years, p<0.0001) and shorter (SDS; -1.6 ± 0.9 vs -1.2 ± 1, p=0.006) than GH-only group. Pubertal growth was significantly greater in patients with GH+GRHa than GH-only (29.0 ± 4.7 cm vs 25.4 ± 4.5 cm, p=0.002), with the largest height gain observed in girls. Subgroup analysis showed significantly greater pubertal growth in GH+GRHa-treated patients with both GHD (27.7 ± 4.8 cm vs. 23.4 ± 5.5 cm, p=0.0005) and SGA (26.2 ± 5.4 cm vs. 22.2 ± 5.2 cm, p=0.01) compared to GH-only. No significant differences in FH were observed between both treatment groups in patients with SGA (p=0.81). Patients with GHD treated with GH+GRHa (shorter at puberty onset with height SDS; -1.6 ± 1 vs -0.9 ±0.8 in GH-only group, p=0.004) remained significantly smaller than GH-only group (FH SDS; -1.4 ± 0.7 vs -0.4 ± 0.9, p<0.0001). Conclusions: The addition of GRHa to GH therapy in children with GHD or SGA and a poor final height prognosis at puberty onset enhances pubertal growth, regardless of sex or underlying condition. Presentation: Saturday, July 12, 2025