AUTHOR=Chondronikola Maria , Volpi Elena , Børsheim Elisabet , Chao Tony , Porter Craig , Annamalai Palam , Yfanti Christina , Labbe Sebastien M. , Hurren Nicholas M. , Malagaris Ioannis , Cesani Fernardo , Sidossis Labros S. 

TITLE=Brown Adipose Tissue Is Linked to a Distinct Thermoregulatory Response to Mild Cold in People

JOURNAL=Frontiers in Physiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2016.00129

DOI=10.3389/fphys.2016.00129

ISSN=1664-042X

ABSTRACT=<p>Brown adipose tissue (BAT) plays an important role in thermoregulation in rodents. Its role in temperature homeostasis in people is less studied. To this end, we recruited 18 men [8 subjects with no/minimal BAT activity (BAT−) and 10 with pronounced BAT activity (BAT+)]. Each volunteer participated in a 6 h, individualized, non-shivering cold exposure protocol. BAT was quantified using positron emission tomography/computed tomography. Body core and skin temperatures were measured using a telemetric pill and wireless thermistors, respectively. Core body temperature decreased during cold exposure in the BAT− group only (−0.34°C, 95% CI: −0.6 to −0.1, <italic>p</italic> = 0.03), while the cold-induced change in core temperature was significantly different between BAT+ and BAT− subjects (BAT+ vs. BAT−, 0.43°C, 95% CI: 0.20–0.65, <italic>p</italic> = 0.0014). BAT volume was associated with the cold-induced change in core temperature (<italic>p</italic> = 0.01) even after adjustment for age and adiposity. Compared to the BAT− group, BAT+ subjects tolerated a lower ambient temperature (BAT−: 20.6 ± 0.3°C vs. BAT+: 19.8 ± 0.3°C, <italic>p</italic> = 0.035) without shivering. The cold-induced change in core temperature (<italic>r</italic> = 0.79, <italic>p</italic> = 0.001) and supraclavicular temperature (<italic>r</italic> = 0.58, <italic>p</italic> = 0.014) correlated with BAT volume, suggesting that these non-invasive measures can be potentially used as surrogate markers of BAT when other methods to detect BAT are not available or their use is not warranted. These results demonstrate a physiologically significant role for BAT in thermoregulation in people. This trial has been registered with Clinaltrials.gov: NCT01791114 (<ext-link ext-link-type="uri" xlink:href="https://clinicaltrials.gov/ct2/show/NCT01791114" xmlns:xlink="http://www.w3.org/1999/xlink">https://clinicaltrials.gov/ct2/show/NCT01791114</ext-link>).</p>