PLOD1 and central precocious puberty: With the peak value of LH ≥5 IU/L after the GnRH stimulation test, activation of hypothalamus-pituitary-gonadal (HPG) axis were presented in 299 precocious girls (153 in the 2016-2019 group and 146 in the 2020 group), diagnosed as central precocious puberty (15).