Brodeur Nicolas, Longtin André, Kenny Glen P, Seely Andrew J E
Department of Physics, University of Ottawa, Ottawa, Canada.
Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada.
Ann N Y Acad Sci. 2025 Aug;1550(1):283-295. doi: 10.1111/nyas.15385. Epub 2025 Jun 26.
Biological organisms are open thermodynamic systems in which internal structure and function arise from a network of heat- and entropy-producing processes, requiring external export of heat and entropy to the environment. System stability, including health and healing, is hypothesized to relate to the mass-normalized rate of entropy production and export, and the capacity to augment both when required. Using a novel methodological framework that allows the continuous measurement of heat fluxes and body temperature, we can estimate internal entropy production and external entropy export in humans during exercise under heat stress. We report the impairment of entropy export leading to entropy accumulation in association with increasing age, reduced fitness, and the presence of diabetes. In all conditions, impairment was also found to be negatively correlated with the VO max fitness measure. Our analyses make use of direct calorimetry to quantify rates of heat loss and indirect calorimetry to measure metabolic heat production and core temperature in real time. Our results highlight the potential relevance of the entropy balance to the definition of health and open the possibility of designing novel therapeutic approaches based on nonequilibrium thermodynamics to improve patient care.
生物有机体是开放的热力学系统，其内部结构和功能源自一个产生热量和熵的过程网络，需要将热量和熵向外排放到环境中。系统稳定性，包括健康和愈合，据推测与质量归一化的熵产生和排放速率以及在需要时增强两者的能力有关。使用一种能够连续测量热通量和体温的新颖方法框架，我们可以估算热应激下运动过程中人体内部的熵产生和外部的熵排放。我们报告了随着年龄增长、体能下降以及患有糖尿病，熵排放受损导致熵积累的情况。在所有情况下，还发现这种受损与最大摄氧量体能指标呈负相关。我们的分析利用直接量热法来量化热损失速率，并利用间接量热法实时测量代谢产热和核心体温。我们的结果突出了熵平衡与健康定义的潜在相关性，并开启了基于非平衡热力学设计新型治疗方法以改善患者护理的可能性。
