Gan Wen Qi, Allen Ryan W, Brauer Michael, Davies Hugh W, Mancini G B John, Lear Scott A
Department of Population Health, Hofstra North Shore-LIJ School of Medicine, Great Neck, New York, USA.
BMJ Open. 2014 Apr 7;4(4):e004743. doi: 10.1136/bmjopen-2013-004743.
Epidemiological studies have demonstrated associations between long-term exposure to traffic-related air pollution and coronary heart disease (CHD). Atherosclerosis is the principal pathological process responsible for CHD events, but effects of traffic-related air pollution on progression of atherosclerosis are not clear. This study aimed to investigate associations between long-term exposure to traffic-related air pollution and progression of carotid artery atherosclerosis.
Healthy volunteers in metropolitan Vancouver, Canada.
509 participants aged 30-65 years were recruited and followed for approximately 5 years. At baseline and end of follow-up, participants underwent carotid artery ultrasound examinations to assess atherosclerosis severity, including carotid intima-media thickness, plaque area, plaque number and total area. Annual change of each atherosclerosis marker during the follow-up period was calculated as the difference between these two measurements divided by years of follow-up. Living close to major roads was defined as ≤150 m from a highway or ≤50 m from a major road. Residential exposures to traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide were estimated using high-resolution land-use regression models. The data were analysed using general linear models adjusting for various covariates.
At baseline, there were no significant differences in any atherosclerosis markers between participants living close to and those living away from major roads. After follow-up, the differences in annual changes of these markers between these two groups were small and not statistically significant. Also, no significant associations were observed with concentrations of traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide.
This study did not find significant associations between traffic-related air pollution and progression of carotid artery atherosclerosis in a region with lower levels and smaller contrasts of ambient air pollution.
流行病学研究已证实长期暴露于交通相关空气污染与冠心病（CHD）之间存在关联。动脉粥样硬化是导致冠心病事件的主要病理过程，但交通相关空气污染对动脉粥样硬化进展的影响尚不清楚。本研究旨在调查长期暴露于交通相关空气污染与颈动脉粥样硬化进展之间的关联。
加拿大温哥华市的健康志愿者。
招募了509名年龄在30 - 65岁之间的参与者，并对其进行了约5年的随访。在基线和随访结束时，参与者接受颈动脉超声检查以评估动脉粥样硬化严重程度，包括颈动脉内膜中层厚度、斑块面积、斑块数量和总面积。随访期间每个动脉粥样硬化标志物的年度变化通过这两次测量的差值除以随访年数来计算。居住在主要道路附近定义为距离高速公路≤150米或距离主要道路≤50米。使用高分辨率土地利用回归模型估计住宅暴露于交通相关空气污染物（包括黑碳、细颗粒物、二氧化氮和一氧化氮）的情况。数据使用调整了各种协变量的一般线性模型进行分析。
在基线时，居住在主要道路附近和远离主要道路的参与者在任何动脉粥样硬化标志物方面均无显著差异。随访后，这两组之间这些标志物年度变化的差异很小且无统计学意义。此外，未观察到与包括黑碳、细颗粒物、二氧化氮和一氧化氮在内的交通相关空气污染物浓度存在显著关联。
在一个环境空气污染水平较低且差异较小的地区，本研究未发现交通相关空气污染与颈动脉粥样硬化进展之间存在显著关联。
