Brown Adipose Tissue Improves Whole-Body Glucose Homeostasis and Insulin Sensitivity in Humans

TLDR

Brown adipose tissue (BAT) is of interest as an antidiabetic tissue because it dissipates energy as heat, yet its role in human glucose metabolism remains unclear despite extensive rodent studies. The study aimed to determine whether BAT activation alters whole‑body glucose homeostasis and insulin sensitivity in humans. Seven BAT‑positive and five BAT‑negative men, matched for age, BMI, and adiposity, were examined under thermoneutral conditions and after 5–8 h of cold exposure. Cold exposure increased resting energy expenditure, whole‑body glucose disposal, plasma glucose oxidation, and insulin sensitivity only in BAT‑positive men, demonstrating BAT’s significant role in human glucose homeostasis and insulin sensitivity.

Abstract

Brown adipose tissue (BAT) has attracted scientific interest as an antidiabetic tissue owing to its ability to dissipate energy as heat. Despite a plethora of data concerning the role of BAT in glucose metabolism in rodents, the role of BAT (if any) in glucose metabolism in humans remains unclear. To investigate whether BAT activation alters whole-body glucose homeostasis and insulin sensitivity in humans, we studied seven BAT-positive (BAT+) men and five BAT-negative (BAT−) men under thermoneutral conditions and after prolonged (5–8 h) cold exposure (CE). The two groups were similar in age, BMI, and adiposity. CE significantly increased resting energy expenditure, whole-body glucose disposal, plasma glucose oxidation, and insulin sensitivity in the BAT+ group only. These results demonstrate a physiologically significant role of BAT in whole-body energy expenditure, glucose homeostasis, and insulin sensitivity in humans, and support the notion that BAT may function as an antidiabetic tissue in humans.