Somatic and psychological effects of low-dose aromatase inhibition in men with obesity-related hypogonadotropic hypotestosteronemia.

INTRODUCTION

Reduced testosterone levels are frequently observed in obese men. Increased aromatase activity may be an etiological factor.

OBJECTIVE

In this study, we evaluate the clinical effects of aromatase inhibition in obesity-related hypogonadotropic hypotestosteronemia (OrHH).

METHODS

Double-blind, placebo-controlled, 6-month trial in 42 obese men with a BMI >35 kg/m(2), and a serum total testosterone <10 nmol/l. All patients started on one tablet of 2.5 mg/week, with subsequent dose escalation every month until a serum total testosterone of 20 nmol/l was reached.

ENDPOINTS

Psychological function, body composition, exercise capacity, and glucose, lipid, and bone metabolism.

RESULTS

Thirty-nine patients completed the study according to protocol. Letrozole decreased serum estradiol from 119.1±10.1 to 59.2±6.1 pmol/l (P<0.001), and increased serum LH from 3.3±0.3 to 8.8±0.9 U/l (P<0.0001) and serum total testosterone from 8.6±0.7 to 21.5±1.3 nmol/l (P<0.0001). Significant effects on the predefined endpoints were not observed.

CONCLUSION

Despite a marked rise in serum testosterone, low-dose aromatase inhibition had no somatic or psychological effects in men with OrHH.