Changes in the hormonal profile and seminal parameters with the use of aromatase inhibitors in the management of infertile men with low testosterone to estradiol ratios

Therapy with 2.5 mg letrozole or 1 mg anastrazole daily, in cases of infertile men with low T/E2 ratios, leads to a significant increase of T/E2 ratio, ejaculate volume, sperm motility, and total motile sperm count.


Odysseas Gregoriou, M.D., Panagiotis Bakas, M.D., Charalampos Grigoriadis, M.D., Maria Creatsa, M.D., Dimitrios Hassiakos, M.D., Georgios Creatsas, M.D.

Vol 98, Issue 1 , Pages 48-51



To compare the effects of 2.5 mg letrozole with those of 1 mg anastrazole daily on the hormonal and semen profiles of a subset of infertile men with low T/E2 ratios.


Prospective, nonrandomized study.


Reproductive medicine clinic.


The study group consisted of 29 infertile men with a low serum T/E2 ratio (<10).


Patients were divided into two groups. Group A included 15 patients treated with 2.5 mg letrozole orally once daily for 6 months, and Group B consisted of 14 patients treated with 1 mg anastrazole orally every day for 6 months.

Main Outcome Measure(s):

Hormonal evaluation included measurement of serum FSH, LH, PRL, T, and E2. In all sperm analyses pretreatment and posttreatment total motile sperm counts (ejaculate volume × concentration × motile fraction) were evaluated.


The use of aromatase inhibitors (either letrozole or anastrazole) in cases of infertile men with low T/E2 ratios improved both hormonal and semen parameters.


This study suggests that some men with severe oligospermia, low T levels, and normal gonadotropin concentration may have a treatable endocrinopathy.

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