Figure 1.

In Vivo Study Visit Protocols

Prednisolone regulation of human BAT activity was measured in vivo in two separate studies using (A) PET/CT and (B) thermal imaging. In both studies, participants spent 2 hr in a warm room, then 2 hr in a cold room to activate BAT. In the PET/CT study, 1 hr into cold exposure, subjects were injected with 75 MBq of 18-fluoro-2-deoxyglucose (¹⁸FDG), and a PET/CT scan was performed 1 hr later. Blood (B) samples were taken at the intervals shown. In the thermal imaging study, at the end of the second hour in the warm room, subjects placed both hands in water cooled to 15°C (W15) as a mild stimulant to activate BAT. Thermal imaging was performed at the intervals shown (T). Whole-body energy expenditure was assessed each hour using indirect calorimetry (IC).