Department of Anthropology, CUNY Hunter College, New York City, New York, USA.
New York Consortium in Evolution Primatology, New York City, New York, USA.
Am J Hum Biol. 2022 Jun;34(6):e23723. doi: 10.1002/ajhb.23723. Epub 2022 Feb 13.
Recent research suggests that brown adipose tissue (BAT) plays a functional role in non-shivering thermogenesis; however, few studies have examined population variation in BAT or its relationship with other mechanisms of adaptation to cold stress. This study characterized BAT thermogenesis and other adaptive responses to low temperatures among Indigenous Siberian young adults and young adults living near Chicago, IL.
We recruited 72 Yakut participants (42 females; 30 males) and 54 participants in Evanston, IL (40 females; 14 males). Anthropometric dimensions and resting metabolic rate (RMR) were measured, and we calculated percent divergence in RMR from expected values (divRMR). We also quantified change in supraclavicular temperature, sternum temperature, and energy expenditure after a mild cooling condition.
Participants in Yakutia were less likely to shiver during the cooling condition (p < .05) and exhibited significantly greater evidence of BAT thermogenesis, warmer sternum temperatures, and higher divRMR than participants in Evanston (p < .05). Additionally, the relationship between change in supraclavicular temperature and energy expenditure differed between the two samples.
Yakut young adults displayed greater evidence of BAT thermogenesis in response to mild cooling compared with young adults living near Chicago, IL. Furthermore, the relationship between BAT thermogenesis and change in energy expenditure appears to be stronger among Yakut adults. Adults that exhibited greater metabolic response to cold stress, such as higher BAT thermogenesis and divRMR, maintained warmer sternum temperatures. These results highlight the degree to which adaptation to cold climates involves multiple integrated biological pathways.
最近的研究表明，棕色脂肪组织（BAT）在非颤抖性产热中发挥着功能作用；然而，很少有研究检测到 BAT 的人群变异及其与适应冷应激的其他机制的关系。本研究描述了西伯利亚原住民年轻成年人和伊利诺伊州埃文斯顿（IL）年轻成年人的 BAT 产热和其他适应低温的反应。
我们招募了 72 名雅库特参与者（42 名女性；30 名男性）和 54 名伊利诺伊州埃文斯顿的参与者（40 名女性；14 名男性）。测量了人体测量维度和静息代谢率（RMR），并计算了 RMR 与预期值的偏差百分比（divRMR）。我们还量化了轻度冷却条件后锁骨上温度、胸骨温度和能量消耗的变化。
雅库特地区的参与者在冷却过程中不太可能颤抖（p<0.05），并且表现出明显更大的 BAT 产热证据、胸骨温度更高和 divRMR 更高，与埃文斯顿的参与者相比（p<0.05）。此外，两个样本之间锁骨上温度变化与能量消耗之间的关系不同。
与生活在伊利诺伊州埃文斯顿的年轻成年人相比，雅库特年轻成年人在轻度冷却下表现出更大的 BAT 产热证据。此外，BAT 产热与能量消耗变化之间的关系在雅库特成年人中似乎更强。表现出更高的代谢对冷应激反应的成年人，如更高的 BAT 产热和 divRMR，保持了更温暖的胸骨温度。这些结果突出了适应寒冷气候涉及多种综合生物学途径的程度。
