ESPE Abstracts

Introduction: MKRN3, kisspeptin and IGF-1 maybe involved into the initiation of puberty. The aim of our research is to evaluate the differences of serum IGF-1, MKRN3 and kisspeptin in girls with central precocious puberty, rapidly progressive puberty, premature thelarche and controls, and further assess the value of IGF-1 in puberty initiation.

Methods: The patients enrolled in the study were divided into four groups: central precocious puberty (CPP), rapid progressive puberty (RPP), premature thelarche (PT)and normal controls. One-way analysis of variance was used when data was normal distribution, Mann-Whitney U test and Kruskal-Wallis H test were used when data was for skewed distribution. Spearman rank correlation was given to assess the correlation. The ROC curve was used to determine the diagnostic value of IGF-1 in identifying the initiation of HPGA. P<0.05 was considered statistically significant.

Results: There were statistically differences in the levels of kisspeptin and IGF-1 among the four groups of CPP, RPP, PT and controls (P=0.003<0.05, P=0.000<0.05), positive correlation was existed between kisspeptin level and bone age, basal LH levels, basal FSH levels, peak LH levels, and the ratio of peak LH and FSH levels (P<0.05), and positive correlation was also existed between IGF-1 levels and estradiol, basal LH levels, basal FSH levels, peak LH levels, and the ratio of peak LH and FSH levels (P<0.05).The area under the curve of ROC of IGF-1 was 0.873. There were no difference in the levels of MKRN3 among the four groups of CPP, RPP, PT and controls (P=0.244>0.05), over 10 years of age, the MKRN3 levels in the Hypothalamic-pituitary-gonadal axis (HPGA) initiated group was lower than the HPGA non-initiated group, the difference was statistically significant (P=0.006<0.005),The overall MKRN3 levels was not correlated with gonadotropin levels (P>0.05), the negative correlation between estradiol and basal LH level appeared only after 10 years (r=−0.464, P=0.034<0.05, r=−0.473, P=0.017<0.05).

Conclusions: MKRN3, kisspeptin and IGF-1 play a regulatory role in the process of puberty initiation, MKRN3 has a large individual variability. Among them, MKRN3 exhibits as an inhibitory factor on GnRH, kisspeptin and IGF-1 manifests the opposite. The expression of MKRN3 is down-regulated after the initiation of HPGA, but the levels of kisspeptin and IGF-1 are up-regulated. In addition, IGF-1 has certain diagnostic value in the differential diagnosis of puberty initiation.