Endocrine Abstracts

Introduction: Kisspeptins and their cognate receptor GPR-54 (Kiss-1) were found to be regulators of the hypothalamo-pituitary–gonadal axis. It is under debate if the onset of central precocious puberty (CPP) could be triggered by early increase of kisspeptin. We aimed to assess serum kisspeptin levels in girls in order to evaluate its potential as a reliable biochemical marker for differential diagnosis of CPP.

Materials and methods: The girls enrolled in our study were divided into three groups: central precocious puberty (CPP), premature telarche (T) and age-matched healthy controls (H). Hormonal serum levels (LH, FSH, estradiol) were measured by an automated immunochemiluminiscent assay. Kiss-1(112–121)amide was measured in sera, using EIA kit (Phoenix Pharmaceutical, Inc.), sensitivity 0.12 ng/ml, range 0–100 ng/ml, CV intra-assay 5–10%, CV interassay <15%. Statistical analysis – SPSS version 16.0.

Results and discussions: Differential diagnosis between CPP and T was made by basal hormonal levels and after triptorelin test, ovarian ultrasound exam and bone age (BA) assessment. There were no differences between demographic characteristics in all three groups. No correlations were found between kisspeptin levels and age, body mass index, BA, LH, FSH (basal or stimulated), ovarian/uterus volume respectively, neither in the whole lot, nor in each group. A wide range of kisspeptin values in CPP girls (0.85–11.52 ng/ml) was obtained.

Surprinsingly, kisspeptin values were greater in healthy group than in CPP group (P=0.04) and than in T group (NS), showing a decreasing tendency with pubertal evolution.

Conclusions: Our results do not sustain circulating kisspeptin levels as useful biomarkers in differentiating between girls with idiopathic CPP and premature telarche.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.

Key words: kisspeptins, central precocious puberty.