Aging affects the cardiovascular responses to cold stress in humans

Abstract

Cardiovascular-related mortality peaks during cold winter months, particularly in older adults. Acute physiological responses, such as increases in blood pressure, in response to cold exposure may contribute to these associations. To determine whether the blood pressure-raising effect (pressor response) of non-internal body temperature-reducing cold stress is greater with age, we measured physiological responses to 20 min of superficial skin cooling, via water-perfused suit, in 12 younger [25 +/- 1 (SE) yr old] and 12 older (65 +/- 2 yr old) adults. We found that superficial skin cooling elicited an increase in blood pressure from resting levels (pressor response; P < 0.05) in younger and older adults. However, the magnitude of this pressor response (systolic and mean blood pressure) was more than twofold higher in older adults (P < 0.05 vs. younger adults). The magnitude of the pressor response was similar at peripheral (brachial) and central (estimated in the aorta) measurement sites. Regression analysis revealed that aortic pulse wave velocity, a measure of central arterial stiffness obtained before cooling, was the best predictor of the increased pressor response to superficial skin cooling in older adults, explaining approximately 63% of its variability. These results indicate that there is a greater pressor response to non-internal body temperature-reducing cold stress with age in humans that may be mediated by increased levels of central arterial stiffness.

Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults

“…Whole body cold stress elicits a robust systemic pressor response (3,4,9,23,62) that is exaggerated in aged adults, evidenced by this and other (23,60) studies. The augmented pressor response to skin surface cooling in older adults is likely not mediated by an increase in cardiac output, as cardiac output derived via transthoracic echocardiography remains unchanged throughout cooling in older adults (60).…”

“…Moreover, because we were interested in the precise effect of primary aging on the neurocirculatory responses to cold exposure, we used a milder cold stress (i.e., no change in core temperature and designed not to induce shivering) to isolate a vasoconstrictor response. Exposure to this magnitude of cooling is likely more indicative of the typical cold stress experienced by older adults (23) and may therefore have greater clinical relevance.…”

“…Reflex cutaneous vasoconstriction is markedly attenuated in healthy older adults, likely mediated by impairments in both end-organ responsiveness (30, 51, 55) and the thermoregulatory control of skin sympathetic nerve activity (19). In young adults, whole body cold stress elicits a pronounced systemic pressor response (3,4,9,23,62), and this pressor response to mild cold stress (i.e., with no reduction in core body temperature) is exaggerated in aged humans (23, 60). The age-related augmentation in the pressor response to acute cold stress is associated with increased central arterial stiffness (23) and increased left ventricular preload (60).…”

“…In young adults, whole body cold stress elicits a pronounced systemic pressor response (3,4,9,23,62), and this pressor response to mild cold stress (i.e., with no reduction in core body temperature) is exaggerated in aged humans (23,60). The age-related augmentation in the pressor response to acute cold stress is associated with increased central arterial stiffness (23) and increased left ventricular preload (60). In addition, sympathetic nervous system activation likely contributes to the cold-induced increase in BP.…”

Improving nursing methods by using thermal imaging: Observations by CAT S60 mobile phone

“…The body temperature decrease below 25 C° may lead to ventricular fibrillation [10]. Myocardial infarction and cardiovascular (CV) related mortality increase in low outdoor temperature [11].…”