Noninvasive assessment of endothelial function in the skin microcirculation.
BACKGROUND
The structure and function of blood vessels varies along the vascular tree. Endothelial dysfunction is a hallmark of increased cardiovascular (CV) risk that can be assessed by several methods, some of which are invasive and of restricted application. The aim of this study was to determine whether the laser Doppler response of skin microcirculation to acetylcholine, reflects that of conduit artery assessed by brachial artery flow-mediated dilation (FMD).


METHODS
Noninvasive measurement of endothelium-dependent vasodilation in the skin microcirculation by laser Doppler flowmetry (LDF) in response to a local transdermal iontophoretic application of acetylcholine (Ach-SkBF) is an operator-independent method. Ach-SkBF and FMD were measured in the nondominant upper limb of 55 unselected consecutive patients admitted in our department for evaluation of CV risk factors.


RESULTS
Ach-SkBF was (mean +/- s.d. (min-max)) 490 +/- 414%, (10-1667%) and FMD was 3.77 +/- 3.01% (0.91-10.91). A strong linear relationship was found between Ach-SkBF and FMD: Ach-SkBF = 122.7 FMD + 25.8 (r = 0.92, P < 0.0001).


CONCLUSIONS
Endothelial dilatory response to increased blood flow and to acetylcholine are similar in large arteries and in the skin microvasculature. Thus, measurement of blood flow changes in the skin microcirculation using LDF coupled with acetylcholine iontophoresis represents a technically challenging and reliable noninvasive method for the assessment of endothelial function within a large range of normal and altered endothelium responses.
Debbabi
Haythem
H
Department of Non-Invasive Investigations, Cardiovascular Research Centre, PARCC Inserm U970, Lariboisière Hospital, Paris, France.
Bonnin
Philippe
P
Ducluzeau
Pierre Henri
PH
Lefthériotis
Georges
G
Levy
Bernard I
BI
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D001916:Brachial Artery / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D007478:Iontophoresis / Q000379:methods*; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology*; D008875:Middle Aged; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D000109:Acetylcholine