Clinical and laboratory findings in the differential diagnosis of central precocious puberty and premature thelarche.

AIM: In this study, it was aimed to evaluate the clinical, antropometric and laboratory findings of female patients diagnosed with central precocious puberty and to determine the laboratory value with the best diagnostic accuracy in the diagnosis of central precocious puberty.

MATERIALS AND METHOD: Female patients whose breast development began before the age of 8 years were included in the study. The data of the patients were obtained by retrospectively examining file records. The chronogical age, age at the time of onset of the complaint, antropometric variables, bone age and hormonal tests were recorded. The patients whose bone age/chronological age ratio was >1 and in whom pubertal response was obtained to gonodotropin releasing hormone stimulation test were considered central precocious puberty and the patients who did not meet these criteria were considered premature thelarche. Receiver operating charecteristic curve (ROC) analysis was performed to determine the diagnostic accuracy of the laboratory variables.

RESULTS: Fifty one patients with idiopathic central precocious puberty and 36 patients with premature thelarche were included in the study. In the patients with central precocious puberty, the height standard deviation score, bone age and bone age/chronological age ratio were found to be significantly higher compared to the patients with premature thelarche. The basal luteinizing hormone, basal follicle stimulating hormone, basal luteinizing hormone/follicle stimulating hormone, peak luteinizing hormone, peak follicle stimulating hormone and peak luteinizing hormone/follicle stimulating hormone values were found to be significantly higher in the patients with central precocious puberty. When the cut-off value for the peak luteinizing hormone/follicle stimulating hormone ratio was taken as >0.24, the sensitivity was found to be 100% and specificity was found to be 84%. When the cut-off value for the basal follicle stimulating hormone was taken as >1.9 IU/L, the sensitivity was found to be 71% and specificity was found to be 68%. When the cut-off value for the basal luteinizing hormone was taken as >0.1 IU/L, the sensitivity was found to be 71% and specificity was found to be 64%.

CONCLUSIONS: In female children, a peak luteinizing hormone/follicle stimulating hormone ratio of >0.24 can be used in the diagnosis of central precocious puberty. However, the findings should be assessed in association with the clinical and antropometric variables.