Growth and Final Height in Girls with Central Precocious Puberty after Long-term Treatment with Depot Gonadoliberin Analogue
Abstract
Objective: Analysis of the growth and factors influencing the final height in girls with central precocious puberty (CPP), treated with a gonadoliberin analogue. Type of study (design): A long-term open clinical study.
Methods: Ten girls with CPP, six of them with idiopathic (ICCP) and four with organicallybased (OCPP) form, respectively, were treated for the period of 3.9+-0,9 y (mean +- S.D.) (range 2.6-6 years) with a depot agonist of gonadoliberin containing the active molecule of triptorelin. The final or almost final height was compared with expected body height acccording to parents (hereditary growth potential) and with a growth prognosis (determined by the projection method) during establishing the diagnosis, at the end of therapy and at menarche.
Factors related to final body height were analyzed. Results: The girls reached final body height of 160.5 +- 6.9 cm, less than the expected height according to their parents (166.0 +- 5.3 cm) (p = 0,03).
Their growth potential was already decreased at the beginning of therapy and improved only insignificantly since then. The height prediction at the time of menarche (162.3 +- 5.4 cm) did not differ from the final height reached (NS).
Significant relations were demonstrated between the final height and age at the beginning of treatment (r = -0.7), the bone age before the end of therapy (r = -0.7) and the growth rate in the first year after the end of therapy (r = 0.7). The higher growth rate in the first year after treatment was observed in girls with a lower bone age at the end of therapy (r = -0.8).
The bone age below 12 years appeared to be optimal for cessation of therapy in our group. Conclusion: Girls who were younger at the beginning of therapy with gonadoliberin therapy reached higher final height.
A timely cessation of the therapy with a gonadoliberin analogue at the bone age of 12 years at the latest proved to be the significant factor for reaching the final height in agreement with the hereditary growth potential.