ESPE Abstracts

Introduction: Most children with isolated GH deficiency (GHD) show a normal GH secretion upon reaching final height (FH). The aimof our study was to identify the predictive factors of persistent GHD and the correlation with the response to recombinant GH (rhGH) therapy in terms of height gain upon reaching FH and compared to target height (TH).

Method: In this retrospective study, we evaluated medical records of GHD subjects treated with rhGH who underwent retesting for persistent GHD during the time interval 2012-2023. For each patient the following data were collected: height SDS, weight SDS, BMI SDS, growth rate, pubertal stage, bone age SDS at different time points (0, 6, 12 months and at treatment discontinuation), TH SDS, type of stimulus and GH peak at diagnosis and at retesting, dose of rhGH, treatment duration, IGF-1 SDS, brain magnetic resonance imaging (MRI).

Results: The sample included 98 patients, 61 males and 37 females, with a mean age of 11.85 y and 11.04 y and a mean height at diagnosis of 138.41±13.7 cm and 131.35±14.3 cm, respectively. Persistent GHD was detected in 35% of patients. No correlation was found with type of stimulation test, GH peak at diagnosis, brain MRI alterations at diagnosis, age at onset, dose of rhGH, treatment duration and type of stimulus at retesting, while a significant correlation was found with IGF-1 SDS at baseline (P <0,05) and with the lower GH peak at retesting (P <0,0001). Female gender was inversely correlated with persistent GHD and showed a higher height gain SDS relatively to TH than males. Growth rate in the first year of treatment was found to be a strong predictor of persistent GHD as well as of a better response to rhGH therapy both in terms of height gain SDS at FH and compared to TH. Furthermore, IGF-1 SDS at baseline and a lower bone age at diagnosis were predictive factors of a better response to rhGH therapy, thus confirming both as prognostic factors for the child’s growth potential.

Conclusion: Further studies are needed to establish clear diagnostic criteria for persistent GHD and, therefore, a possible correlation with the type of GH stimulation test and the cut-off for GH peak at retesting, in order to early identify patients who are candidates for continuing therapy during the transition age.