ESPE Abstracts

Background: There are controversial results among the results of various studies evaluating diagnostic utility of kisspeptin, NKB, AMH, and INHB for demonstrating activation of hypothalamic-pituitary-gonadal axis in girls with CPP.

Aim: To evaluate these 4 neuropeptides in the same individuals who presented with early pubertal signs and their validity in the diagnosis and differential diagnosis of CPP.

Patients: Study included 99 girls (51CPP, 48PT) whose breast development started before 8 years and 42 age-matched healthy prepubertal girls. Clinical and anthropometric findings, pubertal stage at diagnosis, growth velocity, bone age (BA), and pelvic ultrasonography findings, basal/stimulated gonadotropin and basal E2 levels were recorded. GnRH stimulation test was performed in all cases with early breast development. Kisspeptin, NKB, INHB and AMH levels were measured in fasting serum samples.

Results: There was no statistically significant difference between mean age of girls with CPP (n=51), PT (n=48), and prepubertal controls (n=42). Girls with CPP had more advanced BA, lower height-adjusted for BA, higher growth velocity-SDS, higher ovarian volume and uterine longitudinal diameter, higher basal gonadotropin, peak LH and E2 levels (P<0.001 for all parameters). Serum kisspeptin, NKB and INHB levels were higher in CPP group compared to PT and control group, while serum AMH level was lower in CPP group (Table 1). Serum kisspeptin, NKB, and INHB were positively correlated with BA advancement, and peak LH in GnRH test. Multiple stepwise regression analysis revealed that the most important factors used to differentiate CPP from PT were advanced BA, serum kisspeptin, NKB and INHB levels (standardized β coefficients were 1.809, 1.528, 1.321 and 0.725, respectively) (r2:0.889; P<0.001).

Conclusion: We, to the best of our knowledge, firstly showed in the same patients group that serum kisspeptin, NKB and INH levels were higher in CPP patients and can be used as an auxiliary parameter to distinguish CPP from PT in early stages of puberty.