Magnetic resonance imaging reveals human brown adipose tissue is rapidly activated in response to cold

Context. In rodents, cold exposure induces the activation of brown adipose tissue (BAT) and the induction of intracellular triacylglycerol (TAG) lipolysis. However, in humans, the kinetics of supraclavicular (SCV) BAT activation and the potential importance of TAG stores remain poorly defined.

Objective. To determine the time course of BAT activation and changes in intracellular TAG using magnetic resonance imaging (MRI) assessment of the SCV (i.e. BAT depot) and fat in the posterior neck region (i.e. non BAT).

Design. Cross-sectional.

Setting. Clinical research centre.

Patients or Other Participants. Twelve healthy male volunteers ages 18-29 years [BMI=24.7±2.8kg/m2 and body fat percentage = 25.0±7.4% (both mean±SD)].

Intervention(s). Standardized whole-body cold exposure (180 minutes at 18°C) and immediate re-warming (30 minutes at 32°C).

Main Outcome Measure(s). Proton density fat fraction (PDFF) and T2* of the SCV and posterior neck fat pads. Acquisitions occurred ...