Din-Dzietham Rebecca, Couper David, Evans Greg, Arnett Donna K, Jones Daniel W
School of Public Health, Division of Cardiovascular Epidemiology, University of North Carolina at Chapel Hill, North Carolina, USA.
Am J Hypertens. 2004 Apr;17(4):304-13. doi: 10.1016/j.amjhyper.2003.12.004.
Impairment of arterial dilation is thought to occur earlier than arterial wall thickening in the atherosclerotic process. In comparison with whites, African Americans reportedly have a generalized attenuation of their vasodilation mechanisms. We set out to evaluate arterial stiffness and its correlates by ethnicity, hypothesizing that African Americans would have stiffer common carotid arteries (ie, lower arterial distension for a given systolic pressure) than their white counterparts.
The study population included 268 African Americans and 2459 whites, who were aged 45 to 64 years at baseline examination in 1986 to 1989, free of coronary heart disease and stroke/transient ischemic attack, from Forsyth County, North Carolina. The beta stiffness index and pulsatile arterial diameter change were derived from brachial blood pressure and from echo-tracked systolic and diastolic carotid arterial diameters.
African Americans had stiffer carotid arteries than their white counterparts, with a right shift of the beta stiffness index distribution. After adjustment for selected cardiovascular risk factors, the mean beta stiffness index was 9% higher for African Americans (mean +/- SEM: 11.3 +/- 0.3) than for whites (mean +/- SEM: 10.3 +/- 0.1) among participants not taking antihypertensive medication. Socioeconomic status and comorbidities were differentially associated with arterial stiffness by ethnicity. Specifically, the association between these correlates and beta stiffness index was stronger in African Americans than in whites.
This report on arterial mechanics in African Americans suggests that large artery stiffening either occurs earlier, or is more accelerated in African Americans than in whites in our sample, perhaps as a result of earlier exposure to multiple risk factors. This finding may have implications for hypertension prevention, as arterial stiffness is associated with the development of hypertension.
在动脉粥样硬化过程中，动脉扩张功能受损被认为比动脉壁增厚出现得更早。据报道，与白人相比，非裔美国人的血管扩张机制普遍减弱。我们旨在按种族评估动脉僵硬度及其相关因素，假设非裔美国人的颈总动脉比白人更僵硬（即对于给定的收缩压，动脉扩张性更低）。
研究人群包括268名非裔美国人和2459名白人，他们于1986年至1989年进行基线检查时年龄在45至64岁之间，来自北卡罗来纳州福赛斯县，无冠心病和中风/短暂性脑缺血发作。β僵硬度指数和搏动性动脉直径变化由肱动脉血压以及超声跟踪的颈动脉收缩期和舒张期直径得出。
非裔美国人的颈动脉比白人更僵硬，β僵硬度指数分布向右偏移。在对选定的心血管危险因素进行调整后，未服用抗高血压药物的参与者中，非裔美国人的平均β僵硬度指数（均值±标准误：11.3±0.3）比白人（均值±标准误：10.3±0.1）高9%。社会经济地位和合并症与动脉僵硬度的关联因种族而异。具体而言，这些相关因素与β僵硬度指数之间的关联在非裔美国人中比在白人中更强。
这份关于非裔美国人动脉力学的报告表明，在我们的样本中，非裔美国人的大动脉僵硬度要么出现得更早，要么比白人加速得更快，这可能是由于更早接触多种危险因素所致。这一发现可能对高血压预防具有启示意义，因为动脉僵硬度与高血压的发生有关。
