Application of the subcutaneous triptorelin stimulation test for the diagnosis of central precocious puberty

Abstract

Background The gonadotropin-releasing hormone (GnRH) stimulation test using intravenously injected gonadorelin is the gold standard for diagnosis of central precocious puberty (CPP). However, gonadorelin is not always readily available. Objective This study investigated the diagnostic efficacy of the subcutaneous triptorelin test and the appropriate blood sampling time for diagnosis of CPP. Methods We compared clinical data of patients with CPP (n = 74) and premature thelarche (PT) (n = 75) who had been diagnosed with the triptorelin stimulation test (n = 146) versus patients with CPP (n = 3) and PT (n = 37) who had been diagnosed with the gonadorelin stimulation test (n = 74). In the triptorelin test, the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were measured 0, 30, 60, 120, and 180 min (triptorelin 180 min test) and 0, 30, 60, 90, and 120 min (triptorelin 120 min test) after subcutaneous triptorelin injection. In the gonadorelin test, the LH and FSH levels were measured 0, 30, 45, 60, and 90 min after intravenous gonadorelin injection. The clinical parameters of CPP and PT were compared according to the type of stimulant and diagnostic method. Results In the triptorelin test group, girls with CPP had a more advanced bone age and higher mean Tanner stage for breast development than girls with PT, whereas in the gonadorelin test group, girls with CPP and PT were not significantly different. In addition, the triptorelin 120 min test group had higher height standard deviation scores than the gonadorelin test group. In the gonadorelin test group, all girls with CPP exhibited a peak LH response at 30 to 60 min after intravenous gonadorelin injection. In the triptorelin test group, most girls with CPP exhibited a peak LH response at > 120 min (n = 38). Among girls with PT, those in the triptorelin 120 min test group had a higher mean Tanner stage for breast development than those in the triptorelin 180 min test group. Conclusion The diagnostic efficacy of the triptorelin test is as high as that of the gonadorelin test in diagnosis of CPP. Because of the slower LH response in the triptorelin test, the LH level should be measured over a longer period of time in patients with suspected CPP.