Combined diagnostic value of insulin-like growth factor-1, insulin-like growth factor binding protein-3, and baseline luteinizing hormone levels for central precocious puberty in girls.

OBJECTIVES: The golden standard test for diagnosing central precocious puberty (CPP) is the gonadotropin releasing hormone stimulation test, which has many limitations. This study aimed to investigate the value of insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3), and basal luteinizing hormone (LH) levels in diagnosing CPP.

METHODS: Cross-sectional study of the levels of IGF-1, IGFBP-3, and basal LH in girls with a chief complaint of premature breast development. Seventy-nine girls with CPP and 37 girls with premature thelarche (PT) diagnosed at West China Second University Hospital from January 2016 to October 2018 were recruited. All patients underwent physical examination, laboratory tests, uterine and ovarian ultrasound, and bone age tests, only CPP patients underwent pituitary magnetic resonance imaging (MRI). Statistical analysis was performed using the SPSS software 21.0. A receiver operating characteristic curve was used to determine diagnostic value.

RESULTS: The anthropometric data and hormone indicators between CPP and PT were statistically different (p<0.001), except for peak follicle stimulating hormone (FSH) levels (p=0.181). IGF-1, IGFBP-3, and basal LH levels were significantly higher in the subjects with CPP than in those with PT; IGF-1 and basal LH were positively correlated with peak LH and LH/FSH (peak) (p<0.001). The area under the curve (AUC) of IGF-1, IGFBP-3, and basal LH were 0.880, 0.853, and 0.915, respectively. When combined, the AUC reached the highest value of 0.978.

CONCLUSIONS: IGF-1, IGFBP-3, and baseline LH levels were useful in diagnosing CPP. The combined analysis improved the diagnostic effectiveness.