ИСТИНА

Method: a functional test with a subcutaneous administration of 0.1 mg triptorelin (GnRH analog) was performed. Basal (0 point, before drug administration) and stimulated (1 point, 4 hours after drug administration) levels of plasma LH and FSH were determined. The chemiluminescent immunoassay method was used. Patients: female patients with proven CH (n=22, aged 18-37 y.o. Me 22 [21; 29]) and control group – healthy menstruating fertile women (n=10, aged 23-38 y.o. Me 26 [24; 27]). Main outcome measures. Patients: basal LH 0.1-7.4 ME/l (Me 2.16 [0.93; 3.4]), stimulated LH 0.41-93.3 ME/l (Me 24.4 [9.9; 33.9]); basal FSH 0.19-9.3 ME/l (Me 6.09 [2.9; 6.6]), stimulated 3.2-43.7 ME/l (Me 22.45 [9.1; 27.6]). Control group: basal LH 1.8-9.66 ME/l (Me 4.94 [3.6; 5.4]), stimulated 24.7-101.9 ME/l (Me 53.05 [38.8; 80.8]); basal FSH 3-11.5 ME/l (Me 7.28 [5.1; 8.1]), stimulated 13.6-48.7 ME/l (Me 22.4 [18.3; 25.7]). Results. ROC-analysis identified that absolute stimulated LH level ≤35 ME/l pointed to central genesis of hypogonadism with sensitivity 77.3% and specificity 90.0% (AUC ROC curve 0.8364, p=0.0026). Stimulated relative LH has not appropriate reliability. FSH showed low diagnostic value for both absolute and relative stimulated levels (AUC ROC curve<0.6, p>0.1). Conclusion: a functional test with subcutaneous administration of 0.1 mg triptorelin had a high diagnostic value for the determination of hypothalamo-pituitary genesis of hypogonadism (including cases with “normal” basal gonadotropins’ levels) in female patients with intact pituitary region and in the absence of other amenorrhea reasons. Stimulated LH level ≤35 ME/l can be considered as diagnostic criterion in this situation with sensitivity 77.3% and specificity 90.0%.