Abstract：
Endothelial dysfunction is an early predictor of atherosclerosis and cardiovascular disease. Flow-mediated dilation (FMD) is the gold standard to assess endothelial function in humans. FMD reproducibility has been mainly assessed in the brachial artery (BA) with limited research in lower limb arteries. The purpose of this study was to compare FMD reproducibility in the upper limb BA and lower limb superficial femoral artery (SFA) in young healthy adults.Fifteen young healthy adults (nine males; six females) underwent FMD, resting diameter, velocity, and shear rate measurements on three occasions to determine intra-and inter-day reproducibility in both BA and SFA, assessed by coefficient of variation (CV), intraclass correlation coefficient (ICC), and Bland-Altman plots.BA FMD CVs (intra-day: 4.2%; inter-day: 8.7%) and ICCs (intra-day: 0.967; inter-day: 0.903) indicated excellent reproducibility and reliability, while for SFA FMD, both CVs (intra-day: 11.6%; inter-day: 26.7%) and ICCs (intra-day: 0.898; inter-day: 0.651) showed good/moderate reproducibility and reliability. BA FMD was significantly more reproducible than SFA FMD (p < 0.05). Diameter reproducibility was excellent and similar between arteries, while resting velocity and shear rate have lower reproducibility in the BA compared to SFA. Bland-Altman plots displayed no proportional and fixed bias between measurements.In summary, SFA FMD is less reproducible than BA FMD, with identical volume of ultrasound training. Given the increasing interest in using SFA FMD to test the efficacy of interventions targeting lower limb\'s vascular health and as a potential biomarker for peripheral arterial disease risk, future studies should ensure higher levels of training for adequate reproducibility.
摘要：
内皮功能障碍是动脉粥样硬化和心血管疾病的早期预测因子。流量介导的扩张（FMD）是评估人类内皮功能的金标准。FMD的可重复性主要在肱动脉（BA）进行评估，而在下肢动脉的研究有限。这项研究的目的是比较年轻健康成年人上肢BA和下肢股浅动脉（SFA）的FMD可重复性。15名年轻健康成年人（9名男性；6名女性）接受了口蹄疫，静止直径,速度,在三种情况下进行剪切速率测量，以确定BA和SFA的日内和日间再现性，用变异系数(CV)评估，类内相关系数(ICC)，还有Bland-Altman的阴谋.BAFMDCV（日内：4.2％；日间：8.7％）和ICC（日内：0.967；日间：0.903）具有出色的可重复性和可靠性，而对于SFAFMD，两项CV(日内:11.6%;日间:26.7%)和ICC(日内:0.898;日间:0.651)均显示良好/中等的可重复性和可靠性.BAFMD比SFAFMD具有更高的重现性（p<0.05）。动脉之间的直径再现性非常好，相似，与SFA相比，BA的静息速度和剪切速率具有较低的可重复性。Bland-Altman图显示测量之间没有成比例和固定的偏差。总之,SFAFMD的可重复性低于BAFMD，相同体积的超声训练。鉴于人们对使用SFAFMD来测试针对下肢血管健康的干预措施的有效性以及作为外周动脉疾病风险的潜在生物标志物的兴趣与日俱增，未来的研究应确保更高水平的培训,以获得足够的可重复性.
