Departments of Cardiology, Freeman Hospital, Newcastle upon Tyne NE77DN, UK.
Physiol Meas. 2010 Jan;31(1):1-11. doi: 10.1088/0967-3334/31/1/001. Epub 2009 Nov 26.
Laser Doppler fluxmetry (LDF) can non-invasively measure skin microvascular changes in response to acetylcholine (ACh), local heating of the skin and reactive hyperaemia following arterial occlusion. Various studies have used microvascular changes in response to these stimuli, especially ACh iontophoresis and local heating, as a surrogate marker of endothelial function. There are few data in the literature regarding the comparative reproducibility of microvascular perfusion changes induced by the three stimuli. The aim of this study was to systematically assess and compare the reproducibility of skin microcirculatory function in response to each of these challenges. Ten healthy non-smoking subjects (seven males) median age 36 years (range 23-46), with no history of hypertension, diabetes, coronary artery disease or any connective tissue disorder, were studied. Changes in skin microcirculation in response to ACh iontophoresis, local heating of the skin and post-occlusive reactive hyperaemia, on two separate days (median 31, range 11-42 days), were assessed in all subjects. We measured three parameters: the change in perfusion from baseline perfusion (peak minus baseline perfusion), the relative percentage change in perfusion from baseline (peak--baseline)/baseline x 100 (%) and also the time-to-peak perfusion. The reproducibility of the change in perfusion had coefficients of variation (CV) of 9.3% for local skin heating, 19.4% for reactive hyperaemia and 25.5% for ACh iontophoresis. The relative percentage change in perfusion from baseline was more variable with CVs ranging from 23% to 39%. The coefficient of variation of time-to-peak perfusion was 7.0% for heating, 15.1% for reactive hyperaemia and 10.4% for ACh iontophoresis. We have shown that microcirculatory changes measured by the change in perfusion from baseline and time-to-peak perfusion in response to ACh, post-occlusive reactive hyperaemia and local skin heating had good reproducibility when carried out in a controlled environment with a standardized protocol. Relative change in perfusion had relatively poor reproducibility. The change in perfusion and time-to-peak perfusion for local skin heating were the most reproducible overall.
激光多普勒流量metry（LDF）可以无创地测量皮肤微血管对乙酰胆碱（ACh）的变化，皮肤局部加热和动脉闭塞后的反应性充血。各种研究都使用对这些刺激的微血管变化，特别是 ACh 离子电渗法和局部加热，作为内皮功能的替代标志物。关于这三种刺激引起的微血管灌注变化的比较可重复性，文献中数据很少。本研究的目的是系统评估和比较每种刺激引起的皮肤微循环功能的可重复性。10 名健康非吸烟受试者（7 名男性），年龄中位数为 36 岁（范围 23-46），无高血压、糖尿病、冠心病或任何结缔组织疾病史，接受了研究。在所有受试者中，分别在两天（中位数 31 天，范围 11-42 天）评估了皮肤对 ACh 离子电渗、皮肤局部加热和闭塞后反应性充血的微血管变化。我们测量了三个参数：从基础灌注的灌注变化（峰值减去基础灌注），从基础灌注的相对灌注变化百分比（峰值-基础）/基础 x 100（%），以及达到峰值灌注的时间。灌注变化的重复性变异系数（CV）为局部皮肤加热 9.3%，反应性充血 19.4%，ACh 离子电渗 25.5%。从基础灌注的相对灌注变化百分比变化更大，CV 范围从 23%到 39%。达到峰值灌注的时间的 CV 为加热 7.0%，反应性充血 15.1%，ACh 离子电渗 10.4%。我们已经表明，在受控环境中使用标准化方案进行时，通过从基础灌注的灌注变化和达到峰值灌注的时间来测量的微血管变化，对 ACh、闭塞后反应性充血和局部皮肤加热的反应具有良好的可重复性。相对灌注变化的重复性相对较差。局部皮肤加热的灌注变化和达到峰值灌注的时间总体上最具可重复性。
