Adult height after spontaneous pubertal growth or GnRH analog treatment in girls with early puberty: a meta-analysis
In the setting of central precocious puberty (CPP), the motivation for hormonal intervention is to help the child to reach a taller adult stature than she would achieve otherwise. While gonadotropin-releasing hormone analogs (GnRHa) constitute an established treatment for improving adult stature in girls presenting with CPP up to age 6 (true precocious puberty), it is not yet clear whether or not the same is true in the setting of CPP presented in girls beyond age 6 (advance puberty). GnRHa may slow growth velocity, offsetting the anticipated improvement in final height that should have resulted from the increased time before growth plate fusion. Consequently, it's been suggested that growth hormone (GH) should be combined with GnRHa to improve the results.Few controlled prospective studies have been performed with GnRHa in children and many conclusions rely in part on collective expert opinion. Therefore, the literature was searched and relevant studies were selected using the search terms "gonadotropin releasing hormone agonist," "precocious puberty/early puberty," and "GnRH analogue." After selected articles were screened for relevance, the process yielded 8 studies, the results of which were then pooled in a meta-analysis aimed at evaluating the effects of GnRHa therapy both with and without added GH in the setting of early puberty. A significant difference was elucidated in final height and predicted adult height comparing GnRHa and combined GnRHa/GH groups. However, no significant difference was elucidated in final height standard deviation scores (SDS) and initial height SDS when comparing GnRHa and control groups. At the same time, the final analysis revealed no significant difference in final height SDS and initial height SDS when GnRHa and combined GnRHa/GH groups were compared.The results suggest GnRHa therapy may have a positive effect on final adult height in girls with early puberty, while adding GH to the treatment may suggest more advantage. Interpretation of the results requires extreme caution, given the complexity of the outcome analysis. Final height gain may prove to be a more appropriate measure of treatment efficacy in any case.