Growth hormone releasing hormone test for infertile men with spermatogenetic maturation arrest

Growth hormone has an important role in the function of the male reproductive system. We investigated infertile men with impaired growth hormone secretion.

Growth hormone status was studied in 8 fertile men and 9 infertile men with azoospermia due to spermatogenetic maturation arrest. Growth hormone releasing hormone, the specific stimulatory neurohormone, was used in the growth hormone stimulation test. A dose of 100 microg. of growth hormone releasing hormone was infused intravenously and serum growth hormone concentrations were measured at 0, 15, 30, 60, 90 and 120 minutes. Serum follicle-stimulating hormone, luteinizing hormone, prolactin, testosterone and estradiol were also measured before the test.

Serum follicle-stimulating hormone concentrations were significantly increased in the azoospermic group and basal levels of growth hormone were similar to those in the control group. Serum growth hormone concentrations increased after injection of growth hormone releasing hormone and the levels of growth hormone peaked after 30 minutes in both groups. At time 30 minutes growth hormone levels had decreased significantly more in the azoospermic group than in the controls. Men with azoospermia due to spermatogenetic maturation arrest had a low response to the growth hormone releasing hormone test.

Relative growth hormone insufficiency, which may be caused by reduced reactivity to growth hormone releasing hormone in pituitary growth hormone secretory cells, is strongly related to spermatogenic dysfunction.