Anouk A.J.J. van der Lans1, Joris Hoeks1, Boudewijn Brans2, Guy H.E.J. Vijgen1,3, Mariëlle G.W. Visser2, Maarten J. Vosselman1, Jan Hansen1, Johanna A. Jörgensen1, Jun Wu4, Felix M. Mottaghy2,5, Patrick Schrauwen1, and Wouter D. van Marken Lichtenbelt1
1Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, 2Department of Nuclear Medicine, and 3Department of Surgery, Maastricht University Medical Centre+ (MUMC+), Maastricht, Netherlands. 4Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA. 5Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany.
In recent years, it has been shown that humans have active brown adipose tissue (BAT) depots, raising the question of whether activation and recruitment of BAT can be a target to counterbalance the current obesity pandemic. Here, we show that a 10-day cold acclimation protocol in humans increases BAT activity in parallel with an increase in nonshivering thermogenesis (NST). No sex differences in BAT presence and activity were found either before or after cold acclimation. Respiration measurements in permeabilized fibers and isolated mitochondria revealed no significant contribution of skeletal muscle mitochondrial uncoupling to the increased NST. Based on cell-specific markers and on uncoupling protein-1 (characteristic of both BAT and beige/brite cells), this study did not show “browning” of abdominal subcutaneous white adipose tissue upon cold acclimation. The observed physiological acclimation is in line with the subjective changes in temperature sensation; upon cold acclimation, the subjects judged the environment warmer, felt more comfortable in the cold, and reported less shivering. The combined results suggest that a variable indoor environment with frequent cold exposures might be an acceptable and economic manner to increase energy expenditure and may contribute to counteracting the current obesity epidemic.
Full text at: http://www.jci.org/articles/view/68993