The Relationship Between Precocious Puberty and Premature Thelarche withSerum Irisin Levels

Abstract

Background and Aims: Irisin is a newly discovered adipomyokine that occurs by the cleaved from a transmembrane protein called -Fibronectintype III domain containing 5- (FNDC5). Previously, there was a change in irisin levels in different prepubertal and pubertal stages.Although the mechanisms that trigger the onset of puberty cannot be explained yet, there is a hypothesis that peripheral adipose tissue and adipokines secreted there may induce the initiation of puberty by stimulating the central neural network.The aim of our study was to compare the levels of irisin in prepubertal and prepubertal children and to determine whether adipomyokine could be used as a marker. Methods: The study was perfomed in 94 girls, with 33 precocious puberty, 31 premature thelarche and 30 prepubertal volunteers.Age and body mass index (BMI) standard deviation score (SDS) groups were generated.The levels of irisin were compared between groups. Also examined the correlations between irisin and age, BMI-SDS, height-SDS, weight-SDS, bone age, uterine axis, right ovary size, left ovary size, basal FSH, basal LH, peak FSH, peak LH and estradiol (E2). With multiple regression analysis the most important factors that influence the level of the irisin have been identified. Results: The table comparing the precocious puberty, premature thelarche and control group is as follows (Table 1).There was a positive correlation between irisin and BMI-SDS, height-SDS, weight-SDS, bone age, uterine axis, right ovary size, left ovary size, basal FSH, basal LH, peak FSH and peak LH. In the multiple regression analysis, it was observed that the most important factor associated with irisin was the peak LH level, respectively, and age and BMI-SDS respectively. Conclusions: The irisin levels were significantly higher in the precocious puberty group than the premature thelarche and the control group.Although there is a finding supporting the hypothesis that the elevation of irisin may be effective on the onset of puberty, it is not possible to confirm this hypothesis with this study.It can also be thought that increased muscle and fat tissue during puberty may play a role in increasing irisin levels.In spite of this, it was concluded that this increase in iris levels could be useful in the diagnosis of precocious puberty and could be used as a marker after higher number of patients studies.