Outcomes of anastrozole in oligozoospermic hypoandrogenic subfertile men

To determine whether the change in sperm parameters in subfertile hypoandrogenic men treated with anastrozole is correlated to the magnitude of increase in testosterone (T) to estrogen ratio in men responding to treatment.

Retrospective study.

Male fertility clinic.

The study group consisted of 86 subfertile hypoandrogenic men with low T/estradiol (E₂) ratio (n = 78) or a prior aversive reaction to clomiphene citrate (n = 8).

All patients were treated with 1 mg anastrozole daily, administered orally.

Hormone analysis and semen analysis before and after treatment were performed. Hormone analysis included measurements of total T, E₂, sex-hormone binding globulin, albumin, FSH, and LH, and bioavailable T was calculated. Total motile sperm count was calculated from the semen analysis.

In all, 95.3% of patients had an increased serum T and decreased serum E₂ after treatment with anastrozole. Sperm concentration and total motile counts improved in 18 of 21 subfertile hypoandrogenic oligozoospermic men treated with anastrozole. In these men the magnitude of total motile count increase was significantly correlated with the change in the T/E₂ ratio. No improvement was seen in semen parameters of men with azoospermia, cryptozoospermia, or normozoospermia at presentation.

Approximately 95% of men with hypoandrogenism responded with improved endocrine parameters, and a subset of oligozoospermic men (approximately 25% of all patients) displayed significantly improved sperm parameters. In that subset, increase in sperm parameters was correlated with the change in the T/E₂ ratio, which argues for a physiologic effect of treatment.