Comparative study of GnRHa stimulation test and GnRH stimulation test

Abstract

Objective To compare the results of GnRHa stimulation test and GnRH stimulation test in girls with Idiopathic central precocious puberty. Methods The girls aged 6-10 who were diagnosed with early breast development(<8 years old) from January 2016 to June 2018 were randomly divided into GnRHa stimulation test group and GnRH stimulation test group according to clinical manifestations, auxiliary examinations and follow-up.The difference in the results of the stimulation test between the two groups was compared. Results A total of 108 girls were enrolled in this study, and 40(37%) of the GnRHa stimulation tests were performed.Among them, 25(63%) patients with idiopathic central precocious puberty had the confirmed diagnosis, and the GnRH stimulation test was performed.Of the 68(63%) patients, 30(44%) had idiopathic central precocious puberty.The peaks of LH in the GnRHa challenge test group and the GnRH challenge test group were 11.33(6.81, 15.79) and 7.89(5.35, 14.21), and the FSH peaks were 15.68(10.18, 20.06) and 17.26(13.34, 21.42), showing no significant differences (U=1078.50, P=0.07; U=1617.50, P=0.10). The peak values of LH/FSH were 0.86(0.37, 1.17) and 0.52(0.31, 0.83), respectively, and there was a statistical difference(U=953.00, P=0.01). GnRH challenge test showed the ICPP sensitivity of 90.91%(81.10%-100.72%), specificity of 94.29%(86.60%-101.98%), total coincidence rate of 92.65%(86.44 %-98.85%), Yoden index of 0.85( 0.72%-0.98%). Sensitivity of the GnRHa challenge test showed the ICPP diagnosis rate of 95.24%(86.13%-104.35%), specificity of 73.68%(53.88%-93.48%), total coincidence rate of 85.00%(73.93%-96.07%), Yoden index of 0.69(0.47-0.91). Conclusion For the diagnosis of idiopathic central precocious puberty in girls, the GnRHa challenge test is more sensitive than the GnRH challenge test, and the specificity and the Yoden index are both low.Therefore, routine use of GnRHa stimulation test as the replacement of GnRH stimulation test is not recommended. Key words: Central precocious puberty; Girl; GnRHa; GnRH; Stimulation test