Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, ON, Canada.
Microcirculation. 2012 Jan;19(1):65-77. doi: 10.1111/j.1549-8719.2011.00126.x.
Humans residing or working in cold environments exhibit a stronger cold-induced vasodilation (CIVD) reaction in the peripheral microvasculature than those living in warm regions of the world, leading to a general assumption that thermal responses to local cold exposure can be systematically improved by natural acclimatization or specific acclimation. However, it remains unclear whether this improved tolerance is actually due to systematic acclimatization, or alternately due to the genetic pre-disposition or self-selection for such occupations. Longitudinal studies of repeated extremity exposure to cold demonstrate only ambiguous adaptive responses. In field studies, general cold acclimation may lead to increased sympathetic activity that results in reduced finger blood flow. Laboratory studies offer more control over confounding parameters, but in most studies, no consistent changes in peripheral blood flow occur even after repeated exposure for several weeks. Most studies are performed on a limited amount of subjects only, and the variability of the CIVD response demands more subjects to obtain significant results. This review systematically surveys the trainability of CIVD, concluding that repeated local cold exposure does not alter circulatory dynamics in the peripheries, and that humans remain at risk of cold injuries even after extended stays in cold environments.
居住或工作在寒冷环境中的人，其外周微血管的冷诱导血管扩张（CIVD）反应强于生活在世界温暖地区的人，这导致人们普遍认为，通过自然适应或特定适应，可以系统地改善对局部寒冷暴露的热反应。然而，目前尚不清楚这种耐受性的提高是否实际上是由于系统适应，或者是否是由于遗传倾向或对这种职业的自我选择。对反复暴露于寒冷的四肢进行的纵向研究仅显示出适应性反应的不确定性。在野外研究中，一般的寒冷适应可能导致交感神经活动增加，从而导致手指血流量减少。实验室研究提供了对混杂参数的更多控制，但在大多数研究中，即使经过数周的反复暴露，外周血流量也没有一致的变化。大多数研究仅在有限数量的受试者上进行，而且 CIVD 反应的可变性需要更多的受试者才能得出有意义的结果。本综述系统地调查了 CIVD 的可训练性，得出的结论是，反复局部寒冷暴露不会改变外周循环动力学，即使在寒冷环境中长时间停留后，人类仍有患冷伤的风险。
