Objective: We assessed the accuracy of the GnRH agonist test (Triptorelin 0,1 mg) and the human chorionic gonadotropin (hCG) test in comparison with basal sex hormones for the differential diagnosis of constitutional delay of puberty (CDP) and hypogonadotropic hypogonadism (HH) in boys.
Materials and Methods: The study included 56 boys with delayed puberty. The first medical visit was in the 14,5±0,9years. We evaluated LH, FSH, testosterone, anti-Mullerian hormone (AMH), inhibin B and the results of the stimulation tests. The HH was defined by a testicular volume <3cm3 after 2 years follow-up. The patients were divided into two groups: the first group with CDP and testicles ≥3cm3 (n=50) and the second group with HH and testicles <3cm3 (n=6). The second group of boys had additional properties, they are often combine with HH: three boys- anosmia/hyposmia, one boy -defect of the gene Prop-1, one boy- micropenis and anosmia.
Results: At the first visit all patients had the same testosterone (Me 1,2 vs 0,9 nmol/l, P=0,2), AMH (Me 32,3 vs 23,4 pg/ml, P=0,1). However, at the first visit in boys with CDP, hormones were significantly higher, such as, LH (Me 1,1 vs 0,1 IU/ml, P=0,0002), FSH (Me 1,9 vs 0,2 IU/l, P=0,00007), inhibin B (Me 142,3 vs 31,3 pg/ml, P=0,00009), max LH (Me 18,9 vs 0,6 IU/ml, P=0,00007), maxLH/maxFSH (Me 2,3 vs 0,4, P=0,0002) on the GnRH agonist test and Δ testosterone (Me 14,4 vs 1,1 nmol/l, P=0,0001) on the hCG test than in boys with hypogonadotropic hypogonadism. The basal LH ≥0,3 IU/ml had 86% sensitivity, 100% specificity (AUC0,935±0,034, 95% 0,869-1); maxLH/maxFSH ≥1- 92% sensitivity, 100% specificity (AUC0,960±0,025, 95% 0,91-1); Δtestosterone ≥2,7 nmol/l on the hCG test - 98% sensitivity, 100% specificity (AUC,0,996 ± 0,006, 95% 0,985-1) for differential diagnosis of CDP and HH in boys. However, max LH ≥3,5 IU/ml on the GnRH agonist test, basal FSH ≥0, 5 IU/l, inhibin B ≥58 pg/ml had 100% sensitivity and specificity (AUC1±0,95% 11).
Conclusion: The max LH ≥3,5 IU/ml, maxLH/maxFSH ≥1 on the GnRH agonist test and Δ testosterone ≥2,7 nmol/l on the hCG test have an excellent accuracy for the differential diagnosis of CDP and HH in prepubertal boys with delayed puberty. However, basal LH ≥0,3 IU/ml, basal FSH ≥0,5I U/l, inhibin B ≥58 pg/ml are a reliable and less-invasive alternative test.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology