Reduced production rates of testosterone and dihydrotestosterone in healthy men treated with rosiglitazone.

The effect of the thiazolidinedione, rosiglitazone (8 mg/d for 7 days), on the production rates of testosterone (T), dihydrotestosterone (DHT), and cortisol (F) was studied in healthy men (n = 10) using the stable isotope dilution technique and mass spectrometry. Treatment with rosiglitazone resulted in a decrease in the production rates of T from, basal, 318 +/- 62 microg/h to 272 +/- 72 microg/h (P <.05). Production rates of DHT fell from, basal, 21 +/- 6 microg/h to 17 +/- 5 microg/h (P <.05). Hence, the ratio calcuated from the production rates of T and DHT was unchanged (basal, 17 +/- 7; rosiglitazone, 17 +/- 3). Production rates of cortisol were unchanged (basal, 577 +/- 136 microg/h; rosiglitazone, 627 +/- 141 microg/h). These results suggest that a clinically relevant dose of at least one thiazolidindione, rosiglitazone, impedes the production of testosterone in man. Copyright 2003, Elsevier Science (USA). All rights reserved