PROFITH "PROmoting FITness and Health through physical activity" research group, Department of Physical and Sports Education, Sport and Health University Research Institute (iMUDS), Faculty of Sports Science, University of Granada, Granada, Spain.
Department of Medicine, Division of Endocrinology, and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
J Biol Rhythms. 2019 Oct;34(5):533-550. doi: 10.1177/0748730419865400. Epub 2019 Aug 7.
The present study examines whether the daily rhythm of distal skin temperature (DST) is associated with brown adipose tissue (BAT) metabolism as determined by F-fluorodeoxyglucose (F-FDG) uptake in young adults. Using a wireless thermometer (iButton) worn on the nondominant wrist, DST was measured in 77 subjects (26% male; age 22 ± 2 years; body mass index 25.2 ± 4.8 kg/m) for 7 consecutive days. The temperatures to which they were habitually exposed over the day were also recorded. The interday stability of DST was calculated from the collected data, along with the intraday variability and relative amplitude; the mean temperature of the 5 and 10 consecutive hours with the maximum and minimum DST values, respectively; and when these hours occurred. Following exposure to cold, BAT volume and mean and peak standardized F-FDG uptake (SUV and SUV) were determined for each subject via static F-FDG positron emission tomography/computed tomography scanning. Relative amplitude and the time at which the 10 consecutive hours of minimum DST values occurred were positively associated with BAT volume, SUV, and SUV ( ≤ 0.02), whereas the mean DST of that period was inversely associated with the latter BAT variables ( ≤ 0.01). The interday stability and intraday variability of the DST were also associated (directly and inversely, respectively) with BAT SUV ( ≤ 0.02 for both). All of these associations disappeared, however, when the analyses were adjusted for the ambient temperature to which the subjects were habitually exposed. Thus, the relationship between the daily rhythm of DST and BAT activity estimated by F-FDG uptake is masked by environmental and likely behavioral factors. Of note is that those participants exposed to the lowest ambient temperature showed 3 to 5 times more BAT volume and activity compared with subjects who were exposed to a warmer ambient temperature.
本研究旨在探讨年轻成年人的远端皮肤温度（DST）的日常节律是否与棕色脂肪组织（BAT）代谢有关，通过 F-氟脱氧葡萄糖（F-FDG）摄取来确定。使用佩戴在非优势手腕上的无线温度计（iButton），在 77 名受试者（26%为男性；年龄 22 ± 2 岁；体重指数 25.2 ± 4.8 kg/m）连续 7 天测量 DST。同时还记录了他们白天习惯暴露的温度。从收集的数据中计算出 DST 的日间稳定性，以及日内变异性和相对幅度；最大和最小 DST 值所对应的连续 5 小时和 10 小时的平均温度；以及这些小时发生的时间。在暴露于寒冷后，通过静态 F-FDG 正电子发射断层扫描/计算机断层扫描对每位受试者的 BAT 体积以及平均和峰值标准化 F-FDG 摄取（SUV 和 SUV）进行了测定。相对幅度和最小 DST 值连续 10 小时发生的时间与 BAT 体积、SUV 和 SUV（≤0.02）呈正相关，而这段时间的平均 DST 与 BAT 的后两个变量呈负相关（≤0.01）。DST 的日间稳定性和日内变异性也与 BAT SUV 相关（两者均为直接和负相关，≤0.02）。然而，当分析调整为受试者习惯暴露的环境温度时，所有这些关联都消失了。因此，通过 F-FDG 摄取估计的 DST 日常节律与 BAT 活性之间的关系被环境和可能的行为因素所掩盖。值得注意的是，与暴露于温暖环境温度的受试者相比，暴露于最低环境温度的受试者的 BAT 体积和活性增加了 3 到 5 倍。
