Effects of sex hormones and exercise on adipose tissue

Abstract

Adipose tissue is an essential body organ that is profoundly affected by both exercise and female sex hormones. As the body’s major energy reservoir, adipose tissue is extremely sensitive to exercise. That is, exercise-mediated increases in circulating catecholamines are a major stimulus for adipocyte lipolysis, the process that allows for mobilization of the lipid stored in adipose tissue for use by other cells of the body. A major physiological and anatomical difference between sexes is that females have significantly more relative adipose tissue. This important difference is clearly mediated by female sex hormones (e.g., estrogen), which dictate body fat distribution patterns, and appear to also affect the physiological function of adipose tissue. For example, ovary-intact female adipose tissue appears to be more metabolically active and less susceptible to insulin resistance and inflammation compared to that from age-matched males. There are also important differences between males and females in brown adipose tissue (BAT) metabolism, such that females have more relative BAT than males and BAT from females appears more active. It is likely that the female hormone, estrogen plays a large role in those sex differences and estrogen receptor alpha appears to mediate those effects. Finally, there are many interesting similarities between how exercise and estrogen affect the function of adipose tissue. The purpose of this chapter is to provide the reader with a basic understanding of the how exercise and estrogen affect adipose tissue physiology and function; this is done via a comprehensive overview of the most recent scientific literature on this topic.