Alexandra Marie Niclou

ALEXANDRA NICLOU, then a graduate student at University of Notre Dame Notre Dame, Indiana, was awarded funding in August 2020 to aid research on ‘”Cold adaptation in a tropical sample? Measuring the metabolic cost of BAT thermogenesis and its association with blood glucose in Samoa,’ supervised by Dr. Cara Ocobock. This dissertation project investigated the metabolic effects of brown adipose tissue (BAT), a heat-producing tissue activated at cold exposure in 100 adults (59 women, 41 men) between 31-54 years old from Apia, Samoa, a warm climate area with little temperature fluctuations year round. The study inferred BAT activity by comparing metabolic rate or the numbers of calories burned and body heat dissipation between room temperature and cold exposure. Despite no changes in metabolic rate between exposure, BAT was inferred as changes in temperature at the supraclavicular area (BAT location) were significantly smaller compared to changes at the sternum (non-BAT location) between room temperature and cold exposure. Furthermore, substrate metabolism, fasting glucose, and cholesterol levels were compared before and after the cooling phase. While cholesterol levels did not change upon inferred BAT activation, fasting glucose levels and the substrate metabolism index decreased after cooling. These results suggest that when activated BAT relies on both glucose and lipids for fuel. This project’s findings demonstrate that BAT may be found across all populations, independent of climate and adds to the increased understanding of the potential beneficial effects of BAT on type II diabetes and other metabolic syndrome risks.