Thermogenesis is defined as a process, which generates heat by the depletion of energy-rich molecules. Evolutionary, it is an essential process that allows the survival at lower temperatures. Since the discovery of brown adipose tissue (BAT) it is believed that this part of the adipose tissue can dissipate energy for heat thanks to the uncoupling protein 1 (UCP1). Since energy expenditure is increased as a consequence of thermogenesis, pharmacological induction of this pathway presents an interesting therapeutic target to counter obesity. However, recent investigations indicate that white adipose tissue (WAT) is much more versatile and probably essentially indispensable for thermogenesis.~To investigate the mechanism of this futile cycle in WAT we plan to investigate the glucose metabolism in 24 healthy volunteers with 2 exams (one with and one without external cooling) with two substitutes for glucose. We will use 18F-FDG to quantify the glucose influx into WAT using dynamic PET/CT scans and 13C-Glucose to analyze the downstream metabolites.
Investigation of futile cycles in white adipose tissue under cold conditions for thermogenesis using two substitutes for glucose metabolism (18F-FDG and 13C-Glucose).