OBJECTIVE: Inhibin B is secreted by Sertoli cells in response to FSH and is the major feedback regulator of FSH secretion in man. The serum inhibin B level has emerged as a good marker of spermatogenesis and Sertoli cell function. Varicocele has been associated with infertility and disturbed spermatogenesis. We have studied the effect of varicocele treatment on serum inhibin B levels, with the aim of investigating the effect on spermatogenesis and the involvement of the Sertoli cell in varicocele pathophysiology. DESIGN AND PATIENTS: In a pre-post test design, the effect of varicocele surgery on inhibin B levels was studied in 30 infertile men. MEASUREMENTS: Endocrinology (inhibin B, FSH, LH, SHBG and testosterone) and semen analysis (sperm concentration, motility and morphology). RESULTS: In men receiving varicocele treatment, a significant increase in serum inhibin B levels was observed from 133.9 ± 13.4 pretreatment to 167.8 ± 16.1 ng/l after treatment (mean ± SEM, P < 0.0001). No significant changes were observed in serum levels of FSH, LH and testosterone. The serum SHBG level decreased from 32.9 ± 3.5 to 28.6 ± 3.4 nmol/l (mean ± SEM, P = 0.04) and the free androgen index was significantly increased from 66 ± 5.9 pretreatment to 85 ± 6.8 after treatment (P = 0.02, mean ± SEM). Semen analysis showed a significant improvement in sperm concentration, from 6.5 ± 1.9 pretreatment to 19.3 ± 4.9 × 106/ml after treatment (P = 0.003, mean ± SEM), and in sperm motility from the baseline level of 17 ± 3 to 32 ± 4% after treatment (P = 0.001, mean ± SEM). CONCLUSIONS: Varicocele treatment can increase serum inhibin B levels, indicating improvement of spermatogenesis and Sertoli cell function. This finding suggests that the pathophysiology of varicocele involves impairment of Sertoli cell function or a different distribution of germ cell stages.

doi.org/10.1046/j.1365-2265.2001.01302.x, hdl.handle.net/1765/58458
Clinical Endocrinology
Department of Reproduction and Development

Pierik, F., Abdesselam, S. A., Vreeburg, J., Dohle, G., de Jong, F., & Weber, R. (2001). Increased serum inhibin B levels after varicocele treatment. Clinical Endocrinology, 54(6), 775–780. doi:10.1046/j.1365-2265.2001.01302.x