OBJECTIVE: In the present study we aimed to assess the reproducibility of skin microvascular reactivity while fast cooling locally with a custom-designed laser-Doppler flowmetry (LDF) probe. METHODS: Twenty-two healthy volunteers underwent local 15 degrees C cooling on the forearm during 5 (protocol 1, n=12) or 30 min (protocol 2, n=10). Skin blood flow was concomitantly assessed using LDF. Measurements were repeated after 30 min (protocol 1) or 7 days (protocols 1 and 2). Data were expressed as cutaneous vascular conductance (CVC) and percentage of baseline (%BL). Within subject coefficients of variation (CV) and intra-class correlation coefficients (ICC) were calculated. RESULTS: Immediate reproducibility of the 5-min cooling was very good, either expressed as CVC or %BL (CV were 8% and 18%; ICC were 0.85 and 0.78, respectively). However, the 30-min cooling was the most reproducible at 1 week, either as CVC or %BL (CV were 26% and 23%; ICC were 0.86 and 0.75, respectively). Local cooling was well tolerated by all volunteers. CONCLUSIONS: We propose in the present work a reproducible 30-min LDF cooling test. Such a tool could be of great interest to assess microvascular reactivity to local cooling in diseases such as Raynaud's syndrome, and to further evaluate drugs for such diseases. Copyright 2009 Elsevier Inc. All rights reserved.
OBJECTIVE: In the present study we aimed to assess the reproducibility of skin microvascular reactivity while fast cooling locally with a custom-designed laser-Doppler flowmetry (LDF) probe. METHODS: Twenty-two healthy volunteers underwent local 15 degrees C cooling on the forearm during 5 (protocol 1, n=12) or 30 min (protocol 2, n=10). Skin blood flow was concomitantly assessed using LDF. Measurements were repeated after 30 min (protocol 1) or 7 days (protocols 1 and 2). Data were expressed as cutaneous vascular conductance (CVC) and percentage of baseline (%BL). Within subject coefficients of variation (CV) and intra-class correlation coefficients (ICC) were calculated. RESULTS: Immediate reproducibility of the 5-min cooling was very good, either expressed as CVC or %BL (CV were 8% and 18%; ICC were 0.85 and 0.78, respectively). However, the 30-min cooling was the most reproducible at 1 week, either as CVC or %BL (CV were 26% and 23%; ICC were 0.86 and 0.75, respectively). Local cooling was well tolerated by all volunteers. CONCLUSIONS: We propose in the present work a reproducible 30-min LDF cooling test. Such a tool could be of great interest to assess microvascular reactivity to local cooling in diseases such as Raynaud's syndrome, and to further evaluate drugs for such diseases. Copyright 2009 Elsevier Inc. All rights reserved.