Gender does not influence prepubertal growth velocity during standard growth hormone therapy--analysis of United States KIGS data.

ABSTRACT

BACKGROUND: Gender is an important determinant that affects the ultimate dose of growth hormone (GH) used for replacement in adult GH deficiency (GHD). Women require larger doses of GH per body weight to achieve comparable age-adjusted serum IGF-I concentrations than do men. OBJECTIVE: To test whether this is entirely a sex steroid effect or biologically inherent in gender. PATIENTS AND METHODS: We examined growth response to GH (0.25-0.35 mg/kg/week) during the first 2 years of therapy in 147 children (44 girls), and in the first 3 years of therapy in 83 of these children (23 girls). Children were aged 3-8 years at onset of therapy, had peak stimulated GH <10 microg/l, and were reported to be prepubertal during the period of analysis. RESULTS: In the relative absence of sex steroid, there was no gender difference in growth velocity SDS or gain in height SDS during 2 or 3 years of GH therapy. CONCLUSIONS: Inherent gender differences in linear growth response to GH prior to puberty may exist, but are not evident in the first years of GH therapy at this GH dose.