Alexandra Marie Niclou

Brown adipose tissue (BAT) is a relatively understudied, heat-producing tissue in humans. Its thermogenic properties and high metabolic activity under non-shivering cold conditions suggest a role for BAT in cold adaptation. However, this narrow description is the result of studies which focused on predominantly male Western and/or cold climate populations with small sample sizes. This project seeks to assess BAT’s energetic cost and glucose disposal function in a tropical sample. We will infer BAT activity by comparing intra-individual metabolic rate and heat dissipation using indirect calorimetry and thermal imaging technology (suprascapular and chest skin temperature and hand vasoconstriction), respectively, at room temperature and after cooling in a mixed-sex sample in Apia, Samoa. By measuring BAT activity and glucose utilization in a Samoan sample we will not only reveal the possible role of BAT in Polynesian cold adaptation and help elucidate the presence of cold-adapted morphologies in a tropical environment but also build and expand upon the pre-existing knowledge of BAT physiology in different climatic conditions. The findings of this study will thus increase our understanding of the metabolic activity of BAT and shed light on the morphological and physiological relationships allowing for human acclimatization to novel ecologies.