A Response to Human Chorionic Gonadotropin Test in Boys with Normal Gonadal Function and with Hypogonadism

Abstract

Data on standard values of human chorionic gonadotropin (hCG) stimulation in normal boys are limited. Moreover, data on participants definitely diagnosed with hypogonadism are rarely reported. Peak plasma testosterone (T) levels after hCG stimulation in a group of boys (2.0~20.9 years) with definitive primary hypogonadism (PH), secondary hypogonadism (SH) and normal gonadal function (N) were analysed. Peak T in groups of PH, SH and N were <0.1~1.9 ng/ml (below 2.0 ng/ml), 0.3~4.5 ng/ml, and 2.2~11.3 ng/ml, respectively. The lower cut-off point of response to hCG stimulation was 2.0 ng/ml and this value may be useful in the diagnosis of PH. Peak T in normal boys showed a tendency to increase after puberty, so a difference between PH and N might be more pronounced in the pubertal period than in the prepubertal period. On the other hand, it was sometimes difficult to make a diagnosis of SH based only on the hCG test, especially during pubertal period, since the T values for pubertal period overlapped between the SH and the N group. The evaluation of SH might be easily done during the pubertal period, if GnRH test were added in diagnosing SH.