Efficacy of anastrozole in the treatment of hypogonadal, subfertile men with body mass index ≥25 kg/m2

Background: Anastrozole is a non-steroidal fourth generation aromatase inhibitor that stops the conversion of testosterone to estradiol and has been used as empiric medical therapy for the treatment of male infertility in men with an abnormal testosterone-to-estradiol ratio <10 in order to increase endogenous testosterone levels. This study sought to evaluate the efficacy of anastrozole in the treatment of hypogonadal, subfertile men with body mass index greater than 25 mg/kg(2) with respect to hormonal profile, semen parameters and overall fertility status. Methods: Retrospective chart review was performed of hypogonadal, subfertile men with body mass index >= 25 kg/m(2) who were treated with anastrozole (1 mg daily). Hormonal measurements and semen analysis prior to and after treatment was analyzed in 30 men. Total motile count was calculated from semen analysis. Clinical pregnancy rates were recorded. Results: Men treated with anastrozole had increases in follicle stimulating hormone (4.8 versus 7.6 IU/L, P<0.0001), luteinizing hormone (3.4 versus 5.4 IU/L, P< 0.0001), testosterone (270.6 versus 412 ng/dL, P<0.0001) and testosterone-to-estradiol ratio (9 versus 26.5, P<0.0001) and decrease in estradiol level (32 versus 15.9 pg/mL, P<0.01) after 5 months of therapy. Increases in sperm concentration (7.8 versus 14.2 million/mL, P<0.001), total motile count (12.6 versus 17.7 million, P<0.01) and strict morphology (3.0% versus 3.5%, P<0.05) was appreciated. Clinical pregnancy rate for our cohort was 46.6% (14 of 30), with 71.4% (10 of 14) conceiving through in vitro fertilization, 14.2% (2 of 14) through intrauterine insemination and 14.2% (2 of 14) through natural intercourse. Conclusions: Anastrozole improves hormonal profiles and semen parameters in hypogonadal, subfertile men with body mass index over 25 kg/m2 and may aid in achieving pregnancy especially in conjunction with assisted reproductive techniques.