Accelerated versus slowly progressive forms of puberty in girls with precocious and early puberty. Gonadotropin suppressive effect and final height obtained with two different analogs.

OBJECTIVES: To distinguish which children with precocious puberty (PP) and early puberty (EP) should be treated and which followed without therapy. To determine the effect of GnRH analog treatment on the final height of treated patients and compare the effect of two different analogs on gonadotropin suppression and final height.

STUDY DESIGN: Sixteen females with PP or EP with a mean chronological age (CA) of 8.8 +/- 1.4 years and a mean bone age (BA) of 10.8 +/- 1.3 years were treated for a mean of 2.7 +/- 1.0 years with a GnRH analog (triptorelin or leuprolide acetate; group A), while 21 girls with a mean CA of 8.5 +/- 1.0 years, a mean BA of 9.7 +/- 1.4 years and a predicted adult height of >155 cm were followed without therapy (group B). Criteria for treatment were one of: a. predicted adult height (PAH) of <155 cm initially or at any time during follow up; b. PAH over 155 cm with a dramatic decrease in PAH over a 6-month follow-up period; c. advanced and rapidly progressing breast development for age (Tanner 3 before the age of 9 years).

RESULTS: GnRHa therapy suppressed gonadotropins in group A, while gonadotropins increased gradually in group B. Height velocity (HV) decreased in group A, while it remained accelerated in group B; BA increased a mean of 1.7 +/- 0.5 years in group A and 3.2 +/- 0.3 years in group B. This resulted in a height increase in group A from a baseline PAH of 153.7 +/- 1.2 cm to a final height (FH) of 160.9 +/- 4.0 cm (p <0.001), clearly above their target height (TH) of 157.7 +/- 4.2 cm. The height of group B children did not change over time (164.1 +/- 4.1 cm before therapy and 166.0 +/- 6.0 cm at FH), both above their TH. The mean leuprolide acetate dose utilized in this study decreased during treatment, while both the initial and final triptorelin dose remained unchanged. Adequate gonadotropin suppression (peak level of LH and FSH of <2 IU/l after i.v. GnRH stimulation) was noted with both leuprolide acetate and triptorelin, although LH suppression was slightly more pronounced with triptorelin. BA advanced 1.8 +/- 0.4 years during leuprolide acetate treatment and 1.5 +/- 0.3 years with triptorelin, so that FH increased a mean of 5.5 +/- 1.3 cm with leuprolide acetate and 8.7 +/- 2.2 cm with triptorelin.

CONCLUSIONS: PAH of <155 cm before or during therapy, PAH of >155 cm with a dramatic decrease in predicted height over a 6-month follow-up period and/or advanced and rapidly progressing breast development in girls with PP or EP were useful parameters in deciding which patients to treat. GnRHa therapy suppressed gonadotropins, HV and bone maturation in children with an accelerated form of PP or EP, resulting in a significant height increase. Final height remained stable over time in untreated patients. Adequate gonadotropin suppression was noted with both analogs, although with the doses of analog used in our study, LH and BA suppression were more pronounced with triptorelin, resulting in a larger height gain.