ESPE Abstracts

Objective: AMH decreases by 30% in the first two years following puberty. Although it is known that AMH is associated with FSH and LH, the AMH response to rapid changes in GnRH is not known clearly in puberty. It has been shown that AMH levels in central precocious puberty (CPP) are lower than in premature thelarche (PT), but the levels of AMH in peripheral precocious puberty (PPP) have not been evaluated. The aim of this study was to evaluate the basal and stimulated AMH levels in CPP, PPP and PT groups.

Materials and Methods: Patients who had breast development before 8 years old and had underwent GnRH test were included in the study. Blood samples were taken at 0th, 45th and 90th minute of GnRH test from 73 patients. Patients were grouped as SPP, PPP and PT according to clinical and laboratory findings.

Results: The median age of patients was 7.8 (4.1-9.3) years. Of the patients, 43.8% (n: 32) were CPP, 42.5% (n:31) were PT, 13.7% (n:10) were PPP. The median basal AMH levels in the PPP, CPP and PT group were 0.09 ng/ml (0.05-0.31), 0.19 ng/ml (0.05-0.56) and 0.29 ng/ml (0.07-0.77) respectively. There were statistically significant differences in the basal AMH levels between three groups (p:0.0001). The stimulated AMH level was significantly higher than the baseline (p:0.0001). In the 32.9% (n:24) of patients, peak FSH levels were reached in 45th minutes, however in the 74% (n:54) of patients peak AMH levels were reached in 45th minutes at GnRH test. The stimulated/basal AMH levels were significantly different in three groups (p:0.002). The median stimulated/basal AMH ratios in PPP, CPP and PT group were 12.2 (5.7-30.6), 8.9 (2-39.3) and 6.5 (2.3-18.3) respectively. The cut-off value of the stimulated/basal AMH ratio, to differentiate PP group (SPP+PPP) from the PT group, was found to be 6.57 with a sensitivity of 79% and a specificity of 52% (AUC:0.703 p:0.003).

Conclusion: In this study, which examined for the first time the AMH response to GnRH stimulation in puberty, it was found that AMH was significantly increased with GnRH stimulation and AMH was peaked at 45 minutes in ¾ of subjects. It was found that the stimulated/basal AMH ratio was the highest in the PPP group with the lowest basal AMH level; and was the lowest ratio in the PT group with highest basal AMH level.