Metabolic Effects of 5α-Reductase Inhibition in Humans

The study investigated the metabolic effects of 5α-reductase inhibitors, specifically focusing on dutasteride and finasteride, in a sample of 46 men over 3 months. It was found that dutasteride, which inhibits both 5αR1 and 5αR2, led to decreased peripheral insulin sensitivity and increased body fat, while hepatic insulin sensitivity remained unchanged. In contrast, finasteride, which only inhibits 5αR2, did not have these effects. Additionally, both inhibitors caused subtle dysregulation of the HPA axis, more so with dutasteride, though these changes were largely compensated for. The study highlighted potential metabolic implications for patients using dutasteride for benign prostatic hyperplasia.