The Predictive Factors for Central Nervous System Lesion in Central Precocious Puberty and the Utility of Single Timed LH after GnRH Administration

Choi, Jin Ho; Shin, Young Lim; Yoo, Han Wook

Abstract

PURPOSE: This study was undertaken to determine whether the clinical presentation of patients with central precocius puberty(CPP) varies according to the etiology, whether this permits the differentiation between idiopathic and organic forms and to examine whether LH determination in a single timed blood sample after GnRH administration is sufficient to diagnose CPP.
METHODS
This study included 33 girls with signs of breast development, of whom 23 were diagnosed as definite central precocious puberty. Sixteen patients had idiopathic CPP; the remaining 7 patients had organic CPP. Ten patients were classified as non-CPP. Potential clinical and laboratory predictors of CNS abnormalities were assessed and GnRH stimulation test was done.
RESULTS
The age of onset in patients with organic CPP was 4.11+/-2.08 years, whereas the age in patients with idiopathic CPP was 7.25+/-1.34 years. This parameter is the only one showing statistical significance. We compared sensitivities and specificities at 0, 15, 30, 60, 90 and 120 min which yielded sensitivities of 8.7%, 87.0%, 91.3%, 87.0%, 73.9%, 60.9%.
CONCLUSION
It is impossible to exclude a central nervous system lesion in patient with central precocious puberty without performing central nervous system imaging. However, this study indicates earlier the onset of disease, higher the possibility of presence of CNS lesion. According to the mean GnRH stimulated LH levels and sensitivity at each times, a single blood sample obtained for LH determined after GnRH administration at 30 min can be used to diagnose the central precocious puberty.