How bodies respond to cold reveals sex differences in blood flow
Researchers using thermal imaging found that cold exposure triggers different microvascular responses in men and women, with women recovering faster but showing greater individual variation. The findings could improve diagnostic tests for circulatory disorders and inform workplace safety standards for cold environments.
Originaltitel: Microcirculatory response to cold stress test in the healthy hand
<p>Objective: Cold sensitivity of the fingers is common in several conditions. It has been linked to digital vasospasm, microvascular dysfunction, and neural mechanisms. This study aimed to investigate the normal digital micro-vascular response to a cold stress test in healthy individuals using Laser Speckle Contrast Imaging (LSCI).Methods: Twenty-six healthy individuals, mean age 31 (SD 9) years were included. Skin perfusion of digits II-V was measured using Laser Speckle Contrast Imaging before and after a standardized cold stress test. Changes in skin perfusion from baseline were analyzed between hands, digits, and sexes.Results: Skin perfusion was significantly (p &lt; 0.0001) affected by cold provocation in both the cold exposed and the contralateral hands in all participants of the study. This effect was significantly different between the radial (digit II and III) and the ulnar (digit V) side of the hands (p &lt; 0.001). There was a trend towards a larger decrease in perfusion in men (ns), and a faster recovery to baseline values in women (ns). A larger inter subject variability was seen in perfusion values in women.Conclusions: The normal microvascular response to cold provocation may involve both centrally and regionally mediated processes. When exposing one hand to a cold stress test, the contralateral hand responds with simul-taneous but smaller decreases in perfusion.</p>