Aromatase inhibitors in infertile patients: effects on seminal parameters, serum and seminal plasma testosterone levels, and estradiol levels during short-term follow-up

Abstract

Aim: To evaluate the effects of an aromatase inhibitor (anastrozole) on seminal parameters, and on serum and seminal plasma testosterone/estradiol ratios in infertile patients, as well as to clarify its place among empirical infertility treatment modalities. Patients and Methods: The study included 32 patients with spermatozoa numbering > 5 million/mL in ejaculate and a serum testosterone/estradiol ratio < 0.14. Anastrozole, an aromatase-inhibiting agent, was given (1 mg b.i.d.) and patients were re-evaluated 2 months later based on semen analysis, and measurements of serum and seminal plasma testosterone and estradiol levels. Results: Semen analysis parameters before and after treatment, respectively, were as follows: number of spermatozoa: 12.4 +/- 4.1 million/mL and 22.3 +/- 5.7 million/mL; motility: 33.4 +/- 4.2% and 47.6 +/- 7.4%; normal morphology: 5.4 +/- 1.3% and 8.9 +/- 2.7%. Differences between the values before and after treatment were statistically significant (P < 0.05). Serum testosterone level was 4.1 +/- 1.2 ng/mL, estradiol level was 52.1 +/- 9.4 pg/mL, and testosterone/estradiol ratio was 0.13 +/- 0.03 at the beginning of treatment. These values were 3.2 +/- 0.6 ng/mL, 68.4 +/- 7.3 pg/mL, and 0.05 +/- 0.001, respectively, in seminal plasma. Following 2 months of anastrozole treatment, testosterone and estradiol levels, and the testosterone/estradiol ratio showed statistically significant changes in serum and seminal plasma. While testosterone levels significantly increased, estradiol levels decreased (serum P-T = 0.001, P-E2 = 0.001; seminal plasma P-T = 0.001, P-E2 = 0.001). Conclusion: Aromatase inhibitors are a potential treatment method for infertile male patients with increased plasma estradiol levels and decreased plasma testosterone/estradiol ratios.