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

Objective Gradual local heating of the skin induces a largely 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. CVC , 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 CVC and relative CVC responses corrected for maximal CVC at 44°C (% CVC max ). Results Between‐day reproducibility of baseline CVC and % CVC max for both sites was relatively poor (22–30%). At 42°C, CVC and % CVC max responses showed less variation (9–19%), whilst absolute CVC responses at 44°C were 14–17%. Between‐day variation for % CVC max 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 utilized and site‐to‐site variation is minimized.