Dutasteride treatment for benign prostatic hyperplasia (BPH) is associated with a significant increase in serum testosterone and a significant decrease in BMI among men with relatively lower baseline serum testosterone levels, researchers reported in BJU International (2009; published online ahead of print).
The study randomized 120 patients with BPH to receive the α-blocker tamsulosin at a dosage of 0.2 mg/day, the 5α-reductase inhibitor dutasteride at a dosage of 0.5 mg/day, or a combination of these two regimens for one year. After one year of treatment, 107 subjects were evaluable.
Mean serum testosterone levels rose significantly in the dutasteride and combination arms by 16.3% and 15%, respectively, but increased by only 0.3% in the tamsulosin arm. The increases in the dutasteride and combination arms were greatest for those in the lowest tertile of baseline testosterone level.
With respect to BMI, the dutasteride and combination arms had mean decreases of 0.17 and 0.20 kg/m2, respectively, whereas the tamsulosin group had a mean increase of 0.04 kg/m2. The decreases in BMI for the dutasteride and combination arms were significantly only in the lowest tertile of baseline serum testosterone.