The Auxological and Hormonal Differences in Girls with Atypical Thelarche and Central Precocious Puberty

Cho, Won Kyoung; Ahn, Sun A; Park, So Hyun; Hahn, Seung Hoon; Jung, Min Ho; Suh, Byung Kyu

Abstract

PURPOSE:We compared anthropomorphic measures and hormone levels in girls with atypical thelarche (AT) and central precocious puberty (CPP) and tried to find out factors discriminating AT from CPP.
METHODS
We analyzed clinical and laboratory data of 62 girls with precocious breast development from May 2004 to May 2008 at Kangnam St. Marys Hospital. Immunoradiometeric assay (IRMA) was used to estimate gonadotropins and growth related hormones. CPP was diagnosed if peak luteinizing hormone (LH) level was >6.9 IU/L after gonadotropin hormone releasing hormone (GnRH) stimulation test. A multiple logistic regression analysis and the area under the receiver operating characteristics curve (AUC) were used to analyse the prediction capacity of variable factors to diagnose CPP. RESULT:The basal LH levels (P=0.001), IGF-I levels (P=0.049) and the peak LH levels (P<0.001) in GnRH-stimulation test in girls with CPP were higher than those with AT. Girls with AT had a lower degree of breast maturation than girls with CPP (P=0.001). A multivariate logistic regression model including the basal LH levels and IGF-I levels revealed a strong relation of the basal LH levels to CPP [OR:2.7, 95% confidence interval (CI): 1.1-6.7, P=0.035]. The AUC for basal LH levels showed prediction capacity of basal LH levels to diagnose CPP [AUC: 0.70, 95% CI: 0.57-0.81, P=0.009]. The statistically ideal cut-off value of basal LH levels to discriminate CPP from AT was 2.66 IU/L (sensitivity 40%, specificity 98%) and the clinically meaningful cut-off value was 1.86 IU/L (sensitivity 70%, specificity 62%).
CONCLUSION
These results suggest that the basal LH level using IRMA could be a useful parameter discriminating AT from CPP. Further study with larger number of subjects will be needed.