Oral clonidine advances spermatogenesis in oligozoospermic patients with spermatogenetic maturation arrest

Growth hormone (GH) plays an important role in the pubertal development of males and females, and influences the male reproductive function after puberty. The purpose of this study was to investigate the cause of GH deficiency in infertile men with spermatogenetic maturation arrest using the clonidine loading test (GH stimulation test). Based on the results of the loading test, we tried to con fi rm whether clonidine might be usable as a male infertility remedy.

We studied 75 infertile men (55 oligozoospermic and 20 azoospermic men) and 25 normal fertile volunteers. We used the oral clonidine (0.15 mg/m2) loading test to evaluate the GH secretory reserve. Histological diagnoses were performed using testicular biopsy and testicular sperm extraction specimens.

The most important finding was that the clonidine loading test caused a good response in 41 out of 55 (74.6%) patients with oligozoospermia. We treated these 41 good-response patients with oral clonidine, and the sperm count improved in 34 (82.9%) cases, increasing to 12-79 million/mL. Spontaneous pregnancy was subsequently achieved by 10 (24.4%) couples.

These findings also suggest that GH is necessary for spermatogenesis, at least for the process of spermatozoa maturation. Oral clonidine therapy improved the sperm count in patients who showed an excessive response to the clonidine loading test.