PLASMA TESTOSTERONE IN MALE PUBERTY

Abstract

ABSTRACT Plasma testosterone was determined by radioimmunoassay in 36 prepubertal boys with hypospadia prior to and 3 days after stimulation with 5000 IU of human chorionic gonadotrophin (hCG). As a control group, 30 boys of comparable age, predominantly with unilateral cryptorchidism, were studied. The increase in plasma testosterone levels after hCG was (median and range) 204 (83–393) ng/100 ml in the control group, whereas in the hypospadiac group a median increase of only 90 (33–272) ng/100 ml was found. The difference between the median testosterone levels after hCG stimulation in the two groups investigated is statistically highly significant (P < 0.0001). After hCG stimulation, 13 out of the 36 boys with hypospadia did not reach the lowest stimulated testosterone level (87 ng/100 ml) found in the control group. It is concluded that a substantial portion of the aetiologically obscure cases of hypospadia are caused by an endocrine testicular insufficiency.