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

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>Gradual local heating of the skin induces a largely <jats:styled-content style="fixed-case">NO</jats:styled-content>‐mediated vasodilatation. However, use of this assessment of microvascular health is limited because little is known about its reproducibility.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Healthy volunteers (<jats:italic>n</jats:italic> = 9) reported twice to the laboratory. <jats:styled-content style="fixed-case">CVC</jats:styled-content>, derived from laser Doppler flux and mean arterial pressure, was examined in response to a standardized local heating protocol (0.5°C per 150 second from 33°C to 42°C, followed by 20 minutes at 44°C). Skin responses were examined at two locations on the forearm (between‐site). Heating was repeated after a break of 24–72 hours (between‐day). Reproducibility of skin responses at 33–42°C is presented for absolute <jats:styled-content style="fixed-case">CVC</jats:styled-content> and relative <jats:styled-content style="fixed-case">CVC</jats:styled-content> responses corrected for maximal <jats:styled-content style="fixed-case">CVC</jats:styled-content> at 44°C (%<jats:styled-content style="fixed-case">CVC</jats:styled-content><jats:sub>max</jats:sub>).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Between‐day reproducibility of baseline <jats:styled-content style="fixed-case">CVC</jats:styled-content> and %<jats:styled-content style="fixed-case">CVC</jats:styled-content><jats:sub>max</jats:sub> for both sites was relatively poor (22–30%). At 42°C, <jats:styled-content style="fixed-case">CVC</jats:styled-content> and %<jats:styled-content style="fixed-case">CVC</jats:styled-content><jats:sub>max</jats:sub> responses showed less variation (9–19%), whilst absolute <jats:styled-content style="fixed-case">CVC</jats:styled-content> responses at 44°C were 14–17%. Between‐day variation for %<jats:styled-content style="fixed-case">CVC</jats:styled-content>max increased when using data from site 1 on day 1, but site 2 on the subsequent day (25%).</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>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 utilized and site‐to‐site variation is minimized.</jats:p></jats:sec>