Sex differences and aging: Is there a role of brown adipose tissue?

Abstract

In every population across the world, women live significantly longer than men; however, the underlying physiological processes that drive these sex differences in age-specific mortality are largely unknown. Recently, the role of adipose tissue in aging and longevity has been a focus of biomedical research in both humans and rodent models. Specifically, brown adipose tissue, a thermoregulatory tissue originally thought to not exist past infancy in humans, has been shown to potentially play a role in health throughout the lifespan. Females have larger adult brown adipose depots that are not just larger in size but also more efficient in non-shivering thermogenesis. This improved functioning of the brown adipose tissue may potentially lead to improved female health, and we hypothesize that this advantage may be of even bigger significance in the older population. Here, we briefly review what is known about sex differences in aging and how sex differences in brown adipose tissue may be contributing to the female lifespan advantage. These questions have usually been addressed in large experimental studies in rodents as a translational model of human aging. Overall, we propose that a better understanding of the thermogenesis-metabolism nexus is necessary in biomedical research, and sex differences in these factors may contribute to the female longevity bias seen in human populations.

Keywords: Aging; Brown adipose tissue; Longevity; Sex differences.

Figure 1.

Proposed feedback loop scheme of BAT regulation and aging. Sex-specific differences may be involved in each of the outlined parameters. However, these sex differences with age are overall unknown due to a lack of sex specific research (see Figure 2).

Figure 2.

Summarization of a literature search on January 13^th, 2021 for brown adipose tissue (BAT) connected to health, nutrition, aging and life extension and including sex. Used PubMed search engine (https://pubmed.ncbi.nlm.nih.gov/). Overall, there are a maximum of 100 studies analyzing the roles of sex differences, BAT, and any marker of health.