Androgens and the Regulation of Adiposity and Body Fat Distribution in Humans.

The sexual dimorphism in human body fat distribution suggests a causal role for sex hormones. This is of particular importance when considering the role of excess visceral adipose tissue accumulation as a critical determinant of obesity-related cardiometabolic alterations. Scientific literature on the modulation of body fat distribution by androgens in humans is abundant, remarkably inconsistent and difficult to summarize. We reviewed relevant literature on this topic, with a particular emphasis on androgen replacement, androgen effects on selected parameters of adipose tissue function and adipose tissue steroid-converting enzymes. In men, low androgenic status mostly reflected by reduced total testosterone is a frequent feature of visceral obesity and the metabolic syndrome. Regarding testosterone therapy, however, studies must be appreciated in the context of current controversies on their cardiovascular effects. Analyses of available studies suggest that decreases in waist circumference in response to testosterone are more likely observed in men with low levels of testosterone and high BMI at study onset. In women with androgen excess, higher testosterone and free testosterone levels are fairly consistent predictors of increased abdominal and/or visceral adipose tissue accumulation, which is not the case in nonhyperandrogenic women. Regarding mechanisms, androgens decrease adipogenesis and markers of lipid storage in vitro in men and women. Evidence also suggest that local steroid transformations by adipose tissue steroid-converting enzymes expressed in a depot-specific fashion may play a role in androgen-mediated modulation of body fat distribution. Accumulating evidence shows that androgens are critical modulators of body fat distribution in both men and women. © 2018 American Physiological Society. Compr Physiol 8:1253-1290, 2018.