Background: To evaluate the effect of GnRH-analogue triptoreline on the predicted adult height and final height in central precocious puberty (CPP).
Patients and methods: The study included 14 girls with CPP treated for 1-6 years with triptoreline depot (75 micrograms/kg/28 days/i.m.; group 1). The criteria for diagnosis included the following: compelling evidence of rapid progression of puberty, with a bone age (BA) greater than 2 SD above the mean value for chronological age (CA) associated with poor initial predicted final height and growth speed greater than 2 SD above the mean value for age. In addition we obtained data from 6 untreated girls with advanced puberty and good predicted adult height followed during the same period of time (group II). 7 of 14 girls of group I and 5 of 6 girls of group II attained final height.
Results: A decrease in growth speed and an increase and in CA/BA ratio were observed after three years of treatment (+4.9 +/- 0.7 SD to -1.45 +/- 2.63 SD and 0.62 +/- 0.14 to 0.74 +/- 0.09 respectively; P = 0.034; n = 6). The predicted adult height increased significantly after two years of treatment (153.1 +/- 4.49 to 156.94 +/- 5 cm; p = 0.041; n = 10) and was more evident after three years of treatment (153.84 +/- 5.77 to 160.7 +/- 7.5 cm; p = 0.03; n = 6). The final height of 7 girls of group I who attained it was similar to target height (161 +/- 3.1 vs. 159 +/- 1.3 cm; NS) and greater than initial predicted adult height (161 +/- 3.1 vs. 154 +/- 2.1 cm; p = 0.044) and than final height of the 5 girls of group II (161 +/- 3.1 vs. 154.28 +/- 6.1 cm).
Conclusions: Triptorelin depot improves predicted adult height and final height of girls with early central puberty may be over their target height.