Evaluating The Value Of A Single Urinary Sample For Determining Gonadotropin By Immunochemiluminometric Assays After Gonadotropin Releasing Hormone Analogue Stimulating Test

Objective Determining urinary gonadotropin (UGn) of single sample after stimulating test by immunochemiluminometric assays (ICMA),and to investigate the value of UGn levels in gonadotropin releasing hormone analogue (GnRHa) stimulating test.Methods Fifty children suffered from disorders of growth or pubertal development were hospitalized for GnRHa stimulating test. Nocturnal spontaneous 12 h (19:00-07:00) urine before the test, diurnal post-stimulating 5 h (-1.5 h before the test to 3.5 h after the test) single urine in all cases, and diurnal spontaneous 5 h (07:00-12:00) urine before the test in 33/50 cases were collected respctively. Urinary luteinizing hormone (ULH) and urinary follicle-stimulating hormone (UFSH) were assayed.Results (1) Nocturnal spontaneous urine: The correlation between serum peak luteinizing hormone (PLH) and spontaneous ULH (SULH) contents was 0.631, for serum PLH and the ratio of SULH/S 0.609, and for serum PLH and the ratio of SULH/Cr 0.589, respectively, (P = 0.000 in three). The correlation between the ratio of SULH/spontaneous UFSH (SUFSH) and the ratio of PLH/the serum peak follicle-stimulating hormone (PFSH) was 0.636, (P = 0.000). The areas under the receiver operating characteristic (ROC) curves of SULH contents, SULH/S, SULH/Cr and SULH/SUFSH were 0.838, 0.826, 0.821 and 0.713, respectively. (2) Diurnal spontaneous urine: The correlation between serum PLH and SULH contents was 0.712, for serum PLH and SULH/S 0.699, and for serum PLH and SULH/Cr 0.663, respectively, (P = 0.000 in three). The correlation between SULH/SUFSH and serum PLH/PFSH was 0.281, (P = 0.113). The areas under the ROC curves of SULH contents, SULH/S, SULH/Cr and SULH/SUFSH were 0.820, 0.804, 0.801 and 0.585, respectively. (3) Serum spontaneous Gn: The correlation between serum PLH and serum spontaneous LH (SLH) was 0.550, (P = 0.000). The correlation between the ratio of serum SLH/serum FSH (SFSH) and serum PLH/PFSH was 0.662, (P = 0.000). The areas under the ROC curve of serum SLH was 0.748. (4) Diurnal post-stimulating single urine: The correlation between serum PLH and ULH contents was 0.822, for serum PLH and the ratio of ULH/S 0.815, and for serum PLH and the ratio of ULH/Cr 0.828, respectively, (P = 0.000 in three). The correlation between the ratio of ULH/UFSH and serum PLH/PFSH was 0.892, (P = 0.000). The areas under the ROC curves of ULH contents, ULH/S, ULH/Cr and ULH/UFSH were 0.933, 0.930, 0.919 and 0.881, respectively. When ULH contents, ULH/S, ULH/Cr and ULH/UFSH were respectively no less than 0.286 IU, 0.266 IU/m2, 310.158 IU/mol and 0.062, and the sensitivities were 89.3%, 89.3%, 82.1% and 89.3% respectively, and the specificities were 95.5%, 95.5%, 95.5% and 86.4%, respectively. (4) Serum spontaneous Gn: The correlation between serum PLH and serum spontaneous LH (SLH) was 0.550, (P = 0.000). The correlation between the ratio of serum SLH/serum FSH (SFSH) and serum PLH/PFSH was 0.662, (P = 0.000). The areas under the ROC curve of serum SLH was 0.748.Conclusions The ULH contents or ULH/S of a single urinary sample after GnRHa stimulating test by ICMA may well reflect the status of the onset of HPGA in children; and their values are better than nocturnal or diurnal SUGn, and nocturnal SULH is better than diurnal SUGn; and nocturnal SUGn are better than serum spontaneous Gn.