Computational estimation of decline in sweating in the elderly from measured body temperatures and sweating for passive heat exposure

Abstract

Several studies reported the difference in heat tolerance between younger and older adults, which may be attributable to the decline in the sweating rate. One of the studies suggested a hypothesis that the dominant factor causing the decline in sweating was the decline in thermal sensitivity due to a weaker signal from the periphery to the regulatory centres. However, no quantitative investigation of the skin temperature threshold for activating the sweating has been conducted in previous studies. In this study, we developed a computational code to simulate the time evolution of the temperature variation and sweating in realistic human models under heat exposure, in part by comparing the computational results with measured data from younger and older adults. Based on our computational results, the difference in the threshold temperatures for activating the thermophysiological response, especially for sweating, is examined between older and younger adults. The threshold for activating sweating in older individuals was found to be about 1.5 °C higher than that in younger individuals. However, our computation did not suggest that it was possible to evaluate the central alteration with ageing by comparing the computation with the measurements for passive heat exposure, since the sweating rate is marginally affected by core temperature elevation at least for the scenarios considered here. The computational technique developed herein is useful for understanding the thermophysiological response of older individuals from measured data.

Natural and Sun-Induced Aging of Human Skin

“…Aging decreases heat tolerance and elderly individuals are more susceptible to deadly heat strokes during periods of heat waves. Both the decrease in cutaneous vascular function (Kligman 1979) and reduced sweating rate are involved in reduced sweat function with aging (Inoue and Shibasaki 1996a;Inoue et al 1999;Hirata et al 2012). The age-related decreased sweat gland function is believed to develop sequentially from the lower limbs to the upper body and head (Inoue and Shibasaki 1996b).…”

General Practitioners’ Perceptions of Heat Health Impacts on the Elderly in the Face of Climate Change—A Qualitative Study in Baden-Württemberg, Germany

“…A broad range of drugs have been identified to pose a threat in heatwaves because of interfering with the ability to adapt to heat (see Table 1 ). On the other hand, some physiological changes of aging itself can also pose a risk in the absence of disease [ 17 ] such as a reduced number of cutaneous blood vessels or higher temperature thresholds for onset of sweating [ 18 , 19 ].…”

Reduced cell cohesiveness of outgrowths from eccrine sweat glands delays wound closure in elderly skin

“…Numerous reports indicate that aging alters thermoregulation function and heat tolerance in humans [reviewed in (Rittié & Fisher, 2015)]. Although the basis for this reduced physiological reaction remains unclear, local skin changes seem to be generally favored for underlying mechanisms, as opposed to sweat gland or central (hypothalamus) alterations (Inoue et al ., 1999; Dufour & Candas, 2007; Hirata et al ., 2012). Our results here are consistent with indirect effects of skin aging on ESG function.…”