Abstract
The hallmark of puberty is the progressive increase in gonadotropin-releasing hormone
(GnRH) activity, reflected by an increase in the circulating concentration of luteinizing
hormone (LH). The GnRH stimulation test is widely used in the evaluation of precocious
puberty. The aim of our study was to assess the diagnostic utility of basal LH for
the diagnosis of central precocious puberty (CPP) in girls. A total of 803 girls were
referred to Ajou University Hospital for evaluation of precocious puberty between
2008 and 2011. All subjects underwent GnRH-stimulation tests as part of their evaluation.
Serum LH and follicle stimulating hormone (FSH) were measured by immunoradiometric
assay before and after the GnRH injection. Of the 803 subjects, 505 (62.9%) were included
in the pubertal response group and 298 (37.1%) were in the prepubertal response group.
Basal LH level was identified as a significant predictor for CPP. Based on the ROC
curve, the optimal cut off point of basal LH related to ‘pubertal response’ was 1.1 IU/l,
which was associated with 69.1% sensitivity and 50.5% specificity, with an area under
the ROC curve of 0.620 (95% CI, 0.581–0.660). It is concluded that a single basal
LH measurement can be used as a screening test to identify girls with CPP and to determine
who should undergo GnRH stimulation test.
Key words
luteinizing hormone - GnRH stimulation test - precocious puberty
