Final height after long-term treatment with triptorelin slow release for central precocious puberty: importance of statural growth after interruption of treatment. French study group of Decapeptyl in Precocious Puberty.

The impact of treatment of central precocious puberty (CPP) with GnRH agonists on final statural height (FH) remains controversial, and guidelines on the optimal time point for interruption of these treatments have not been established. We analyzed the long term results of 58 girls and 8 boys uniformly treated with triptorelin slow release formulation (Decapeptyl, triptorelin-SR) for CPP and compared their FH with predicted height before treatment and with the FH of a historical group of patients not treated with GnRH agonist. The FH SD score was close to 0 and was not different from the genetic target height. In girls, FH was improved by 4.8 +/- 5.8 cm compared with predicted height before treatment and by 8.3 cm by comparison with a historical group. In boys, comparison with a historical group revealed a 13.7-cm improvement, whereas predicted height before treatment was similar to FH. Three variables were independently associated with FH in girls: the bone age/statural age ratio at the onset of treatment (negatively), the height SD score at the end of treatment, and the posttreatment growth spurt (delta FH - height at the end of treatment). The influence of the posttreatment growth spurt, itself dependent on age and bone age at the interruption of treatment, suggests that continuing treatment beyond the age of 11 yr in girls does not improve and could actually decrease FH. This point should be evaluated in a formal controlled trial.