Changes in body mass index in girls with idiopathic central precocious puberty under gonadotropin-releasing hormone analogue therapy: The Spanish registry: The Spanish registry

Background: The influence of gonadotropin-releasing hormone analogue (GnRHa) treatment on body mass index (BMI) evolution in girls with idiopathic central precocious puberty (CPP) is unclear. Hence, we aimed to evaluate the effect of GnRHa treatment on BMI-standard deviation score (SDS) from diagnosis of idiopathic CPP until adult height. Methods: An observational study of girls diagnosed with CPP in Spain was carried out between January 2008 and December 2014. A computer program was designed to process clinical and biological data from patients treated in 55 departments of pediatric endocrinology throughout the country. The inclusion criteria were (1) girls diagnosed with CPP before 8 years of age; (2) born after 1992; (3) with a difference between bone and chronological age of at least 1 year, and (4) with a luteinizing hormone peak >7 U/l during luteinizing hormone-releasing hormone testing. The influence of GnRHa treatment on BMI-SDS evolution was analyzed. Results: Data from 333 girls (22.2% adopted) were evaluated. We report follow-up data at 6, 12, 24, 36, 48 and 60 months and adult height from 269, 232, 198, 153, 105, 56 and 49 girls, respectively. During treatment, there was an increase in BMI-SDS of 0.43 ± 1.17 (95% CI: 0.20-0.64). At adult height (n = 49), BMI-SDS was 1.51 ± 1.38, which was 0.60 ± 1.09 higher than at diagnosis (95% CI: 0.43-0.75). Conclusions: During treatment with GnRHa, girls experience a significant increase in BMI-SDS that persists after therapy is stopped and adult height has been reached.