Diagnostic Usefulness of Subcutaneous Triptorelin Stimulation Testing in the Evaluation of Central Precocious Puberty in Girls

The limited availability of gonadorelin has resulted in an increased use of subcutaneous triptorelin to diagnose central precocious puberty; however, studies validating its diagnostic value remain limited. This study aimed to evaluate the usefulness of subcutaneous triptorelin stimulation testing for central precocious puberty evaluation. We retrospectively reviewed the medical records of 662 girls aged less than 8 years who were tested for central precocious puberty at the Ajou University Hospital in 2021. Luteinizing hormone responses were analyzed to compare the timing of the maximal luteinizing hormone response and the earliest diagnostic point between the triptorelin and gonadorelin groups. Receiver operating characteristic curve analysis was performed to assess discriminatory ability. Central precocious puberty was diagnosed in 219 girls (130 in the gonadorelin group and 89 in the triptorelin group). Both stimulating agents elicited significant luteinizing hormone level rises in patients with central precocious puberty to similar peak luteinizing hormone levels (13.9±12.8 vs. 12.8±12.1 IU/L). Gonadorelin responses peaked at 30 minutes, whereas triptorelin responses peaked later, with 31.5% of patients with central precocious puberty showing a maximal luteinizing hormone level at 120 minutes. All patients with central precocious puberty were identified 60 minutes after gonadorelin administration, whereas approximately 10% of patients with central precocious puberty were diagnosed at 90 and 120 minutes after triptorelin administration. Single-time-point luteinizing hormone measurements showed high concordance with serial sampling, peaking at 60 minutes for gonadorelin and at 120 minutes for triptorelin. A 120-minute triptorelin stimulation test demonstrates luteinizing hormone response patterns similar to those observed with gonadorelin testing and may serve as a practical option for central precocious puberty evaluation.