The recent results observed in precocious puberty and the hope that interrupting puberty might increase adult height have led to an attempt to use GnRH agonist(GnRHa) in children with premature puberty and a poor growth prognosis. We aimed to analyze the growth promoting effect of GnRHa in girls with early puberty and low predicted adult height(PAH).

Thirty six girls were recruited. They were grouped according to the GnRHa treatment period(group 1>6 mo, n=18; group 2<6 mo, n=18). The following variables were analyzed before and after GnRHa treatment : chronological age(CA), bone age(BA), Δage(CA-BA), height, target height (TH), PAH, serum IGF-1, IGFBP-3.

Duration of the GnRHa treatment was 0.89±0.81 yr(1.37±0.92 yr in group 1, and 0.41± 0.08 yr in group 2). Before treatment, none of the variables were different between the two groups. There were no differences in the following variables the between two groups at the end of treatment : CA, BA, Δage, PAH, serum IGF-1, IGFBP-3. But, growth velocity(GV) and PAH increment during treatment were significantly reduced in group 1. Compared with initial PAH, PAH at the end of treatment was significantly increased(3.7±3.2 cm). The last serum levels of IGF-1 and IGFBP-3 were lower than those before treatment.

Even though last PAH didn't approach TH, short term GnRHa administration in early puberty with low predicted PAH was somewhat effective. But, GnRHa administration suppressed the growth hormone-IGF-1 axis. Therefore, it is recommended that growth hormone(GH) should be used in combination with GnRHa.