ESPE Abstracts

Background: In girls with central precious puberty (CPP), the hypothalamic-pituitary-gonadal axis is prematurely activated. If the girl is treated with GnRH agonist (GnRH-a), gonadotropins levels become suppressed.

Objective and hypotheses: We aimed to evaluate whether serum antimu llerian hormone (AMH) and inhibin B levels are affected in girls with CPP and whether pituitary suppression by GnRH-a affects serum AMH and inhibin B levels.

Method: Thirty-six girls who were diagnosed with CPP by GnRH stimulation test followed during GnRH-a treatment. We analyzed serum AMH and inhibin B levels before, 6 and 12 months after initiation of treatment. To investigate whether AMH and inhibin B levels were affected in girls with CPP, baseline levels were compared with levels in age-matched healthy girls (n=35).

Results: Before treatment, serum AMH levels (mean±S.D.) in girls with CPP showed no significant difference compared with levels in controls (7.5±6.8 vs 7.1±2.4 ng/mL, P=0.742). However, serum inhibin B levels in girls with CPP were significantly higher than that in controls (66.7±51.4 vs 16.4±7.9 pg/ml, P<0.001). After 6 months of treatment, AMH declined to 5.3±3.7 ng/ml (P=0.016) and inhibin B also decreased to 37.8±29.4 pg/ml (P<0.001). The AMH and inhibin B levels were more suppressed after 12 months of treatment (AMH: 4.4±3.2 ng/ml, P<0.001, inhibin B: 22.5±19.8 pg/ml, P<0.001). At baseline, serum AMH levels were not correlated with basal LH, basal FSH, peak LH, peak FSH, Estradiol and inhibin B levels.

Conclusion: Our results suggest that the partial suppression of AMH by GnRH-a treatment is mediated by direct ovarian suppression, not by pituitary suppression. Further studies including the result after discontinuation of treatment are needed to prove these findings.