GNRH1 and central precocious puberty: The present study examined the utility of basal LH and LH/FSH ratio with GnRH agonist stimulation testing at different times (30, 60, 90, and 120 minutes after stimulus) for diagnosing idiopathic CPP in 1,492 subjects in order to identify the most feasible and effective diagnostic index to be collected at a single time point.