Hypogonadism in chronically lead-poisoned men

The hypothalamic-pituitary-testicular axis was evaluated in ten men with occupational lead exposure, nine of whom had noted a decrease in libido and frequency of intercourse following this exposure. Six of these men had clinically apparent lead-poisoning while four were classified as being only lead-exposed. The results of the endocrine evaluation of these patients were compared to those obtained on nine age and socioeconomically matched control patients. Both lead-poisoned and lead-exposed patients had reduced basal serum testosterone levels and normal basal serum testosterone-estradiol-binding globulin capacity, estradiol, LH, FSH, and prolactin levels. Both groups demonstrated an appropriate rise in serum testosterone following hCG stimulation and a normal increment in serum FSH in response to clomiphene citrate and gonadotropin-releasing hormone in comparison to the control group. The lead-poisoned patients demonstrated a significantly reduced increment in serum LH after clomiphene citrate and gonadotropin-releasing hormone administration while the lead-exposed patients had normal LH dynamics. Testicular biopsies carried out on the two most severely lead-poisoned men demonstrated peritubular fibrosis, oligospermia and vacuolization of the Sertoli cells. These results suggest that lead poisoning may lead to a pituitary-hypothalamic defect in LH secretion and may also result in direct testicular seminiferous tubular injury.