van Mil Anke C C M, Hartman Yvonne, van Oorschot Frederieke, Heemels Annemieke, Bax Nikki, Dawson Ellen A, Hopkins Nicola, Hopman Maria T E, Green Daniel J, Oxborough David L, Thijssen Dick H J
aRadboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands bResearch institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK cDivision of Human Nutrition, Wageningen University, Wageningen, The Netherlands dSchool of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia, Australia.
J Hypertens. 2017 May;35(5):1026-1034. doi: 10.1097/HJH.0000000000001274.
Carotid artery reactivity (CAR%), involving carotid artery diameter responses to a cold pressor test (CPT), is a noninvasive measure of conduit artery function in humans. This study examined the impact of age and cardiovascular risk factors on the CAR% and the relationship between CAR% and coronary artery vasodilator responses to the CPT.
Ultrasound was used to measure resting and peak carotid artery diameters during the CPT, with CAR% being calculated as the relative change from baseline (%). We compared CAR% between young (n = 50, 24 ± 3 years) and older participants (n = 44, 61 ± 8 years), and subsequently assessed relationships between CAR% and traditional cardiovascular risk factors in 50 participants (44 ± 21 years). Subsequently, we compared left anterior descending (LAD) artery velocity (using transthoracic Doppler) with carotid artery diameter (i.e. CAR%) during the CPT (n = 33, 37 ± 17 years).
A significantly larger CAR% was found in young versus older healthy participants (4.1 ± 3.7 versus 1.8 ± 2.6, P < 0.001). Participants without cardiovascular risk factors demonstrated a higher CAR% than those with at least two risk factors (2.9 ± 2.9 versus 0.5 ± 2.9, P = 0.019). Carotid artery diameter and LAD velocity increased during CPT (P < 0.001). Carotid diameter and change in velocity correlated with LAD velocity (r = 0.486 and 0.402, P < 0.004 and 0.02, respectively).
Older age and cardiovascular risk factors are related to lower CAR%, while CAR% shows good correlation with coronary artery responses to the CPT. Therefore, CAR% may represent a valuable technique to assess cardiovascular risk, while CAR% seems to reflect coronary artery vasodilator function.
颈动脉反应性（CAR%），涉及颈动脉直径对冷加压试验（CPT）的反应，是一种评估人体传导动脉功能的非侵入性方法。本研究探讨了年龄和心血管危险因素对CAR%的影响，以及CAR%与冠状动脉对CPT的血管舒张反应之间的关系。
在CPT期间，使用超声测量静息和峰值颈动脉直径，CAR%计算为相对于基线的相对变化（%）。我们比较了年轻参与者（n = 50，24±3岁）和老年参与者（n = 44，61±8岁）之间的CAR%，随后在50名参与者（44±21岁）中评估了CAR%与传统心血管危险因素之间的关系。随后，我们在CPT期间（n = 33，37±17岁）比较了左前降支（LAD）动脉速度（使用经胸多普勒）与颈动脉直径（即CAR%）。
与老年健康参与者相比，年轻健康参与者的CAR%明显更大（4.1±3.7对1.8±2.6，P < 0.001）。没有心血管危险因素的参与者的CAR%高于至少有两个危险因素的参与者（2.9±2.9对0.5±2.9，P = 0.019）。CPT期间颈动脉直径和LAD速度增加（P < 0.001）。颈动脉直径和速度变化与LAD速度相关（r = 0.486和0.402，分别P < 0.004和0.02）。
年龄增长和心血管危险因素与较低的CAR%相关，而CAR%与冠状动脉对CPT的反应具有良好的相关性。因此，CAR%可能是评估心血管风险的一种有价值的技术，而CAR%似乎反映了冠状动脉血管舒张功能。
