Long-term effects on testicular function of high-dose testosterone treatment for excessively tall stature.

High-dose testosterone treatment is applied during puberty to reduce the predicted adult height in excessively tall boys. To date it has remained unclear whether this therapy produces any long-term effects on reproductive functions of the patients. To clarify this question, we performed a follow-up study in 47 tall men, determining seminal and hormonal parameters 10.6 +/- 2.5 years (mean +/- SD) after cessation of therapy. The tall men treated were compared with 123 normal men attending the Institute of Reproductive Medicine as volunteers for various clinical studies. Clinical examination revealed a significantly higher prevalence of varicoceles and history of maldescended testes in the testosterone-treated tall men compared with the controls. Semen analysis revealed significantly lower progressive motility in the tall men compared with the normal men (49.2 +/- 13.4 vs. 54.3 +/- 12.8%). A nonsignificant tendency towards lower sperm concentration (43.8 +/- 35.4 vs. 57.8 +/- 45.6 mL/mL), lower total sperm count (184.4 +/- 158.0 vs. 225.4 +/- 277.5 mL/ejaculate), and reduced normal sperm morphology (27.6 +/- 12.5 vs. 30.9 +/- 13.1%) was evident in the testosterone-treated tall men. Although there was no difference in testicular volume and FSH between the groups, testosterone was lower in the testosterone-treated tall men (19.9 +/- 7.4 vs. 23.9 +/- 7.0 nmol/L). Statistical analysis of the subgroups of testosterone-treated tall men and control men without varicocele and cryptorchidism revealed no differences in any ejaculate parameter. The small difference in semen variables may be explained by a higher prevalence of varicocele and maldescended testes in the testosterone-treated tall men.