Healthy aging in humans is associated with progressive deterioration of various organ systems, the cardiovascular system being one of the most notable. Young arteries have a pronounced ability to dilate and constrict to mediate changes in blood flow in response to various stimuli (e.g. exposure to a cold or hot environment). With increasing age, complex structural and functional changes to the blood vessels occur which are further exacerbated by common comorbidities including hypertension, diabetes mellitus and hypercholesterolemia. These changes in both the endothelial and smooth muscular layers of the vasculature are mediated through impaired dilator signalling pathways (e.g. nitric oxide signaling and endothelium-derived hyperpolarizing factor) along with augmented contractile pathways (e.g. renin-angiotensin system and endothelin-1). These age-related changes along with the intimal accumulation of lipids (i.e., atherosclerosis, which can strongly impede dilator function) are thought to span the entire arterial tree. In older adults, the impairments in cardiovascular function are most evident during passive heat stress and/or exercise. Recent reports have indicated that passive exposure to heat that elicits a marked increase in body core temperature, and therefore dilation of the arterial tree, may improve macro- and microvascular dilator function in young adults. Given that older adults exhibit a greater capacity for improvement in dilator function, it is possible that chronic heat exposure, or heat therapy, could improve dilator function of the arterial tree which may have multiple health benefits.
- Heat stress
- Cardiovascular disease
- Heat therapy
- Copyright © 2017, American Journal of Physiology-Heart and Circulatory Physiology