Adaptability of older adults to heat with reference to water balance

老年人对热应激的适应性与水分平衡有关。热习服对老年人水平衡的影响9名老年人和6名青年人进行了为期8天的热运动应激，比较了第1天和第8天的体温和水平衡调节反应。结果显示，老年人的体液量较低，水和盐的损失较高，由于缺乏口渴而导致的饮水量较低，与水有关的激素的反应性较低，对热的适应性较差。提示这些因素与老年人热损伤发生率较高有关（提交美国生理学杂志）.根据1968 ~ 1994年全国死亡统计资料，对中暑死亡的流行病学进行了分析。日本在热浪肆虐的几年中报告了大约150例死亡，而1994年在热浪严重的情况下报告了589例。在中暑死亡的人中，64%是老年人（提交给国际生物统计学杂志）。脱水对体温调节的影响本文综述了本实验室有关脱水对体温调节影响的实验结果，（《脑研究进展》，第115卷，脑功能热环境）和高渗（重定向自Clinical & Basic Pharmacology）本研究的实验结果显示，老年人中暑的高发生率与老年人体内水平衡水平较低有关。

Adaptability of older adults to heat stress was assessed in relation to water balance.1. Changes in water balance with heat acclimation in older adultsNine oIder and 6 younger adlts were exposed to heat-exercise stress for 8 days, and regulatory responses in body temperature and water balance were compared on the first and 8th day. The results obtained shown lower body fluid volumes, higher losses of water and salts, lower water intake due to the lack of thirst, lower responsiveness of water related hormones, and lesser acclimation to heat in older subject. It is suggested that these factors are relevant to the higher incidences of heat casualty in the elderly (submitted to American Journal of Physiology).2. Epidemiology of heat strokeBased on the National Death Statistics between 1968 and 1994, the epidemiology of heat stroke death was analyzed. About 150 deaths have been reported in the years with heat waves in Japan, while 589 cases were reported in 1994 with sever heat waves. Out of the heat stroke death, 64% were found in the elderly people (submitted to International Journal of Biometeorology).3. The effects of dehydration on body temperature regulationThe experimental results from our laboratory on the effects of dehydration on body temperature regulation were reviewed dividing the effect of hypovolemia (Progress in Brain Research, Vol. 115, Brain Function Hot Environment) and hyperosmolality (Reviews in Clinical & Basic Pharmacology).The experimental findings obtained in this projects suggests that the high incidences of heat casualty in the elderly are related to the lower level of water balance in older subjects.