[Comparison of oestradiol and testosterone levels in peripheral blood and spermatic cord blood in patients with secretory azoospermia].

OBJECTIVE

Comparison of testosterone and oestradiol levels in spermatic cord blood and peripheral blood as a function of the results of testicular sperm extraction by surgical biopsy in a population of patients with nonobstructive azoospermia (NOA).

MATERIAL AND METHODS

Prospective, comparative, teaching hospital-sponsored, ethics committee-approved study of 30 patients with NOA. Plasma testosterone and oestradiol assays in peripheral blood and blood taken from the spermatic vein during testicular biopsy were performed simultaneously for each patient. Statistical analyses were performed with Mann-Whitney test and Spearman's correlation coefficient by univariate and multivariate analysis of variance (p<0.05).

RESULTS

No significant correlation was demonstrated between spermatic and peripheral blood levels of testosterone and oestradiol, regardless of the biopsy results. The spermatic oestradiol/testosterone ratio was significantly increased when testicular sperm extraction was negative (p=0.018).

CONCLUSION

The increase of the oestradiol/testosterone ratio in spermatic cord blood in the case of negative testicular sperm extraction suggests the hypothesis of greater conversion of testosterone to oestradiol in the testes. This could reflect increased aromatase activity in the absence of germ cells. Further studies using tissue markers of spermatogenesis should provide a better understanding of the physiological role of oestrogens in spermatogenesis and to refine the indications for testicular biopsy in patients with NOA.