IMPE Abstracts

Context: Growth hormone (rhGH) treatment has been shown to be effective in improving growth velocity and the adult height (AH) of short children born SGA if started early on. It is less effective when used to treat short SGA adolescents, as some fail to exhibit catch-up growth.

Objective: The primary objective of this study was to evaluate the impact of Gonadatropin Releasing Hormone analogues (GnRHa), in addition to rhGH, on pubertal growth and near AH in short SGA adolescents.

Patients and Design: Forty-two short SGA adolescents from the KIGS database who had entered puberty (28 females) were treated with rhGH and GnRHa. We fitted a LOESS model to estimate the association between age and height outcomes. Twelve of these children (6 girls) were followed until near AH. Based on age at the start of rhGH therapy we were able to match these subjects to 24 SGA subjects treated with rhGH alone followed until near AH.

Results: Delta height from the start to the end of GnRHa, adjusted for the expected rhGH effect (cm) was significantly dependent on treatment duration (r=0.36; P=0.020). A LOESS regression analysis, showed a decline over time in predicted height SDS in the rhGH alone group vs. an increase in the rhGH and GnRHa group. Height velocity and height velocity SDS outcomes were equal or greater in the rhGH and GnRHa group from approximately 15.5 years of age. Near AH was 154.1 cm in the rhGH alone matched group vs. 157.8 cm in the rhGH and GnRHa cohort. Total pubertal height gain was 19.1 cm in the rhGH alone group vs. 21.8 cm in the rhGH and GnRHa cohort, respectively.

Conclusion: Delaying puberty through short-term GnRHa treatment improves the growth velocity and the near AH of short rhGH treated SGA children.