Between‐day reliability of local thermal hyperemia in the forearm and index finger using single‐point laser Doppler flowmetry

Objective To assess between‐day reliability for LTH in glabrous and nonglabrous index finger skin and nonglabrous forearm skin, with single‐point laser Doppler flowmetry. Methods Part‐1: In healthy, habitually active males (n=10), LTH was examined twice (~7‐10 days apart) for both skin types on the index finger. Part‐2: Identical testing was performed on the volar forearm. Local heating (33‐42°C at 1°C·20 s −1  + 20 minutes at 44°C) was performed at all skin sites and baseline, initial peak, and plateau phases were identified. Data were expressed as raw CVC (laser‐Doppler flux/MAP), and as CVC normalized to baseline (% CVC 33°C ) and maximum heating (% CVC 44°C ). Reliability was assessed using between‐day mean difference, % CV , and ICC. Results Reliability (% CV ) was poor at baseline for all forms of data presentation and for other phases with % CVC 33°C . At the initial peak and plateau, reliability was moderate‐poor (20%‐26%) for CVC and good‐moderate (6%‐18%) for % CVC 44°C . Reliability was good‐moderate for vasodilatory onset time (10%‐23%) and time to initial peak (6%‐13%). Conclusions For all sites, LTH reliability was acceptable for the timing, and for the initial peak and plateau using CVC or % CVC 44°C .