Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia.
Evelpidon Military Academy, Vari, Greece.
Int J Biometeorol. 2020 Jul;64(7):1221-1231. doi: 10.1007/s00484-020-01898-w. Epub 2020 Mar 19.
Seasonal variations in day length and light intensity can affect the circadian rhythm as well as some characteristics of temperature regulation. We investigated characteristics of autonomic (ATR), behavioural (BTR) and nocturnal (NTR) temperature regulation during spring and autumn. Eleven participants underwent experiments in both seasons. To assess ATR, participants performed a 30-min bout of submaximal upright exercise on a cycle ergometer, followed by 100 min of water immersion (28 °C). Thresholds for the onset of shivering and sweating and vasomotor response were measured. BTR was assessed using a water-perfused suit, with participants regulating the water-perfused suit temperature (Twps) within a range, considered as thermally comfortable. The Twps changed in a saw-tooth manner from 10 to 50 °C; by depressing a switch, the direction of the Twps changed, and this limit defined the thermal comfort zone (TCZ) for each participant. A 24-h proximal (calf)-distal (toe) skin temperature gradient (∆Tc-t) was measured to assess NTR. Initiation of vasomotor tone, shivering and sweating was similar between trials. Width of the TCZ was 8.1 °C in spring and 8.6 °C in autumn (p = 0.1), with similar upper and lower regulated temperatures. ∆Tc-t exhibited a typical circadian rhythm with no difference between seasons. Minor changes in skin temperature and oxygen consumption (p ˂ 0.05) between the seasons may indicate a degree of seasonal adaptation over the course of winter and summer, which persisted in spring and autumn. Other factors, such as country, race, sex and age could however modify the outcome of the study.
季节变化对昼长和光照强度的影响，可能会对昼夜节律以及体温调节的某些特征产生影响。我们研究了春季和秋季自主神经（ATR）、行为（BTR）和夜间（NTR）体温调节的特征。11 名参与者在两个季节都进行了实验。为了评估 ATR，参与者在自行车测力计上进行了 30 分钟的亚最大强度的直立运动，随后进行了 100 分钟的水浸（28°C）。测量了颤抖和出汗的起始阈值以及血管运动反应。BTR 使用水灌注服进行评估，参与者将水灌注服温度（Twps）调节在一个范围内，认为这是舒适的温度。Twps 以锯齿状方式从 10°C 变化到 50°C；通过按下开关，Twps 的方向发生变化，该限制为每个参与者定义了热舒适区（TCZ）。测量了 24 小时近端（小腿）-远端（脚趾）皮肤温度梯度（∆Tc-t），以评估 NTR。血管运动张力、颤抖和出汗的起始时间在各次试验之间相似。春季 TCZ 的宽度为 8.1°C，秋季为 8.6°C（p=0.1），调节的上下温度相似。∆Tc-t 表现出典型的昼夜节律，两个季节之间没有差异。皮肤温度和耗氧量的季节变化较小（p＜0.05），这表明在冬季和夏季的过程中可能存在一定程度的季节性适应，这种适应在春季和秋季持续存在。然而，其他因素，如国家、种族、性别和年龄，可能会改变研究结果。
