Reproducibility of Cutaneous Vascular Conductance Responses to Slow Local Heating Assessed Using seven‐Laser Array Probes

Abstract

Objective. Gradual local heating of the skin induces a largely nitric oxide(NO)-mediated vasodilatation. However, use of this assessment of microvascular health is limited because little is known about its reproducibility.Methods. Healthy volunteers (n=9) reported twice to the laboratory. Cutaneous vascular conductance (CVC), derived from laser Doppler flux and mean arterial pressure, was examined in response to a standardised local heating protocol (0.5ºC per 150s from 33-42ºC, followed by 20-minutes at 44ºC). Skin responses were examined at two locations on the forearm (betweensite). Heating was repeated after a break of 24-72 hours (between-day). Reproducibility of skinresponses at 33-42ºC is presented for absolute CVC and relative CVC-responses corrected for maximal CVC at 44ºC (%CVCmax).Results. Between-day reproducibility of baseline CVC and %CVCmax for both sites was relatively poor (22-30%). At 42ºC, CVC and %CVCmax responses showed less variation (9-19%), whilst absolute CVC-responses at 44ºC were 14-17%. Between-day variation for %CVCmax increased when using data from site 1 on day 1, but site 2 on the subsequent day (25%).Conclusion. Day-to-day reproducibility of baseline laser Doppler-derived skin perfusion responses is poor, but acceptable when absolute and relative skin perfusion to a local gradual heating protocol is utilised and site-to-site variation is minimised.

Historical reviews of the assessment of human cardiovascular function: interrogation and understanding of the control of skin blood flow

“…These data can provide important information on the neural or non-neural control of skin blood flow that may, in turn, provide an index of overall vascular health and function/dysfunction (Holowatz et al 2008). Because of the small area and volume of skin under the laser Doppler flow probe and the inherent heterogeneity of the skin microvasculature, and direct site-to-site and dayto-day comparisons of the raw laser Doppler flux signal are highly variable (Braverman et al 1990;Wardell et al 1994;Dawson et al 2015;Roberts et al 2017). To account for potential anatomical differences, a normalisation process is typically utilised.…”

Effect of sinusoidal leg cycling exercise period on brachial artery blood flow dynamics in humans

“…The forearm skin SR was determined in an enclosed location by capacitance hygrometry, calculated from the relative humidity and temperature (THP-B3T; Shinei, Japan) of the air flowing out of a 12.56-cm 2 capsule at a rate of 1.5 L/min [29]. The reproducibility of the SBF measurement using the laser-Doppler flowmeter was confirmed in the previous studies (coefficient of variance: ~ 20%) [30][31][32]. The variables described above were converted into digital data by using an analog-to-digital (AD) conversion device and software (PowerLab 8/35, ADInstruments, Colorado Springs, CO, USA) at 1 kHz.…”

Temporal evolution of neurovascular coupling recovery following moderate‐ and high‐intensity exercise

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