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Thermally-induced cutaneous vasodilatation in aging
1Creighton University Geriatric Center, Department of Family Practice, Omaha, Nebraska.
Journal of Gerontology
|March 1, 1993
Summary
Older adults experience reduced skin blood flow during heat exposure, particularly at nutritive capillary sites. This impaired cutaneous vasodilation may contribute to increased heat stress in the elderly population.
Area of Science:
- Physiology
- Gerontology
- Thermoregulation
Background:
- Heat-induced cutaneous vasodilation is crucial for thermoregulation.
- A decline in this response is suspected in elderly heat stress.
- Understanding age-related changes in skin blood flow is vital.
Purpose of the Study:
- To investigate age-related differences in skin blood flow response to local heat.
- To differentiate responses at nutritive versus arteriovenous anastomotic (AVA) sites.
Main Methods:
- Laser Doppler velocimetry used on 82 healthy volunteers (39 young, 43 elderly).
- Skin blood flow measured at 35°C and 44°C at various body sites.
- Analysis included microvascular volume (VOL) and red blood cell velocity (VEL).
Main Results:
- No significant difference in skin blood flow at 35°C between age groups.
- Older adults showed significantly lower skin blood flow at 44°C at nutritive sites (knee, elbow).
- No age-related difference observed at AVA-rich sites (finger, toe pulp).
- Reduced VOL and VEL observed in older subjects at nutritive sites at 44°C.
- Linear decline in blood flow, VOL, and VEL with age at nutritive sites.
Conclusions:
- Thermally-induced cutaneous blood flow is impaired in older individuals at nutritive capillary beds.
- Arteriovenous anastomotic (AVA) blood flow remains preserved in the elderly.
- Reduced nutritive blood flow may underlie increased heat stress susceptibility in aging populations.