Diagnostic value of stimulated urine luteinizing hormone after triptorelin stimulation test in girls with CPP.

OBJECTIVE: To investigate the diagnostic value of urine luteinizing hormone (ULH) after triptorelin stimulation test detected by immunochemiluminometric assay (ICMA) in girls with central precocious puberty (CPP).

METHODS: The girls with precocious puberty were involved. The triptorelin stimulation test at 8:30 a.m.were performed. Two consecutive 12-hour urine samples were collected after the test, defined as first 12-hour and second 12-hour urine, respectively. ICMA measured ULH. Urine creatinine (Cr) concentration was measured. CPP and peripheral precocious puberty (PPP) were diagnosed by the same pediatric endocrinologist based on clinical symptoms, signs, and progression of clinical development.

RESULTS: A total of 97 cases (CPP n=69; PPP n=28) were included, with 12 cases not meeting the receiver operating characteristic analysis criteria. The first and second 12-hour ULH/Cr in CPP group were higher than those in PPP group. When first 12-hour ULH/Cr was ≥ 287.252 IU/mol, the sensitivity and specificity for diagnosing CPP were 87.3% and 90.9%, respectively. When second 12-hour ULH/Cr was ≥ 152.769 IU/mol, the sensitivity and specificity for diagnosing CPP were 92.1% and 90.9%, respectively. The area under the curve of first and second 12-hour ULH/Cr were 0.933 and 0.954, respectively.

CONCLUSION: The ULH detection method after the triptorelin stimulation test has clinical significance for diagnosing CPP in girls. When the compliance of blood sampling in girls with precocious puberty is poor, first 12-hour ULH/Cr ≥ 288 IU/mol (or second 12-hour ≥ 153 IU/mol) after the triptorelin stimulation test can serve as a laboratory indicator for diagnosis of CPP.