THU193 Clinical Usefulness Of Repetitive GnRH Stimulation Test For The Diagnosis Of Central Precocious Puberty

Disclosure: S. Heo: None. Y. Shim: None. H. Lee: None. J. Hwang: None. J. Lim: None. Objective In girls, breast development under 8 years of age and peak serum luteinizing hormone (LH) is 5 IU/L or higher in gonadotropin releasing hormone (GnRH) stimulation tests is a standard method for diagnosing central precocious puberty (CPP). Although breast development and bone age progress rapidly compared to chronological age, repeated GnRH stimulation tests do not exceed 5 IU/L in some cases. We aimed to analyze the clinical characteristics of girls who repeatedly examined the GnRH stimulation test. Methods We retrospectively reviewed the medical records of 988 girls under 9 years of age who visited our hospital due to breast development more than Tanner stage II and whose bone age was more than a year advanced than the chronological age and examined GnRH stimulation test twice or more. According to peak luteinizing hormone (LH) at first GnRH stimulation test, patients were divided into 5 groups that < 1.0 IU/L (group 1, n=34), ≥1.0 to < 2.0 IU/L (group 2, n=219), ≥2.0 to < 3.0 IU/L (group 3, n=297), ≥3.0 to < 4.0 (group 4, n=252) and ≥4.0 to < 5.0 (group 5, n=186). We analyzed the incidence of CPP through the repetitive GnRH stimulation test and factors associated with the outcomes using a Cox proportional hazard model. Results Mean age of total of 988 girls was 7.68 ± 0.67 years and the period between the first and last GnRH stimulation test was 216.40 ± 145.14 days. CPP was diagnosed in 138 patients. Incidence of CPP were differed by groups that 0%, 1.4%, 6.1%, 20.6%, 34.9% each groups. When group 1 and each groups were compared using the Cox proportional hazard regression model, difference between bone age and chronological age (95% CI, 1.27-2.35, p<0.001) (BA-CA) and basal follicle-stimulating hormone (95% CI, 1.01-1.48, p=0.039) showed a statistically significant positive correlation when stratifying the peak LH at GnRH stimulation test. Conclusion In the diagnosis of CPP, the GnRH stimulation test is gold standard. But the lower the peak LH in GnRH stimulation test, the more other factors such as difference between bone age and chronological age, basal FSH should be considered in the possibility of CPP. Presentation: Thursday, June 15, 2023