ESPE Abstracts

Background: The central precocious puberty (CPP) diagnosis is usually based on clinical evaluation but in its soon phase this evaluation is difficult so laboratory confirmation is crucial.

Objective and hypotheses: To evaluated the usefulness of the Leuprolide stimulation test as a diagnostic method of idiopathic CPP.

Method: Sixty-one girls, aged 5–8 years, were evaluated retrospectivaly for premature breast development. Girls were divided in two groups, according to the clinical characteristics evolution in 6 months, in progressive puberty (n=28) and nonprogresive puberty (n=33). In the first visit we measure serum concentration of FSH, LH and estradiol and we also measure serum concentration of FSH, LH at 3 h and estradiol at 24 h, after a s.c. injection of 0.5 mg of aqueous leuprolide. Receiver operating characteristic (ROC) curves were used to select the best criterion and cut-off point to predict progressiveness of puberty. In both groups we evaluated the sensitivity and especificity of the leuprolide test to predict puberty evolution.

Results: A pubertal hormonal pattern was defined as at least one of the following values: baseline LH: >0.1 mUI/l, baseline FSH: >2.3 mUI/l, peak LH: >5.5 mUI/l, baseline estradiol >12 pg/ml, peak estradiol: >79.67 pg/ml. baseline LH/FSH ratio >0.23, and stimulated LH/FSH ratio >0.24. Stimulated and baseline concentration of LH, stimulated and baseline estradiol and the stimulated and baseline LH/FSH ratio were significantly higher in girls with progressive puberty with respect to girls with nonprogressive puberty group. The measurement LH/FSH ratio post stimulation with Leuprolide had 100% of sensitivity and 94.3% of specificity (based on the ROC curve with an area under the curve of 0.992) to classify progression puberty.

Conclusion: Although measuring basal gonadotropins could allow discrimination between pubertal and prepubertal values, the measurement of LH/FSH ratio, LH and estradiol post stimulation with Leuprolide could be very useful in the diagnosis of CPP in the early phase. However clinical judgment and follow up continues to be of great importance in the evaluation of precocious puberty.