Effect of Aromatase Inhibitors (letrozole) on Spermogram Parameters and Hormonal Profile in Infertile Men

Background & aim: There is no reliable treatment for men with idiopathic infertility, but the relationship between severe sperm production and the ratio of estrogen to testosterone levels has been shown. Aromatase is an enzyme that plays important role in converting testosterone to estradiol and rostenedione to estrogen. Aromatase inhibitors can increase testosterone and androgen production without increasing the amount of estrogen in circulation. The aim of this study was to evaluate the effect of aromatase inhibitors on male infertility. Method: This pre- and post-quasi-experimental clinical trial was carried out on 41 men with an infertility diagnosis. The basic hormonal profile included FSH, LH, testosterone, and estradiol and the ratio of testosterone to serum estradiol was also calculated and recorded. The sperm analysis was performed before the treatment and the seminal parameters were evaluated and recorded. Patients were then treated with letrozole 2.5 mg daily for 4 months and at the end of 4 months, the hormonal profile was studied and seminal analysis performed and recorded. Results: The levels of FSH, LH, testosterone, and estradiol, and the ratio of testosterone to estradiol, increased significantly after treatment. The semen volume, sperm concentration, sperm motility, and sperm forward motion increased, statistically significant in sperm concentration, sperm motility, and sperm forward motion. Morphology decreased, but statistically insignificant. Conclusion: The ratio of testosterone to estradiol levels in infertile men treated with aromatase inhibitors improved and caused changes in sperm parameters. Letrozole may be used to improve sperm parameters in infertile men with low serum testosterone to estradiol ratio.

Keywords:

Male infertility , Aromatase inhibitor , Testosterone , Estradiol