The Utility of Basal Serum Luteinizing Hormone Levels for Screening Central Precocious Puberty in Girls

Background: This study was conducted to examine if basal luteinizing hormone (LH) levels could be useful for screening central precocious puberty (CPP) in girls. Methods: A total of 90 girls under the age of 8 years were included in this study. They underwent the gonadotropin-releasing hormone (GnRH) stimulation test at Good Gang-An Hospital from March 2008 to December 2012 for evaluation of premature sexual development. Patients were classified into two groups: the pubertal response group of patients who had 5 IU/L peak LH levels in the GnRH stimulation test, and the prepubertal response group of patients who had LH levels <5 IU/L. Chronological and bone ages, height, weight, body mass index, gonadotropin response to GnRH stimulation, and basal levels of LH, follicle-stimulating hormone, and estradiol were studied in both groups. The relationship between basal LH and peak-stimulated LH was evaluated using Spearman's correlation. To determine the optimal cut-off values of basal LH levels for differentiating between two groups, the receiver operating characteristic (ROC) curves were analyzed. Results: When the correlation between basal LH levels and peak LH after GnRH stimulation was analyzed in all subjects (N=90), basal LH levels had a statistically significant positive correlation with peak stimulated LH levels (rs=0.493, p<0.001). The cut-off level of optimal basal LH was 0.1 IU/L, according to the ROC curves. Its sensitivity was 73.3%, and its specificity was 77.8%. Conclusion: The study results showed that serum basal LH levels are useful for screening CPP in girls.