Ambient Air Pollution and the Progression of Atherosclerosis in Adults

Abstract

BackgroundCross-sectional studies suggest an association between exposure to ambient air pollution and atherosclerosis. We investigated the association between outdoor air quality and progression of subclinical atherosclerosis (common carotid artery intima-media thickness, CIMT).Methodology/Principal FindingsWe examined data from five double-blind randomized trials that assessed effects of various treatments on the change in CIMT. The trials were conducted in the Los Angeles area. Spatial models and land-use data were used to estimate the home outdoor mean concentration of particulate matter up to 2.5 micrometer in diameter (PM2.5), and to classify residence by proximity to traffic-related pollution (within 100 m of highways). PM2.5 and traffic proximity were positively associated with CIMT progression. Adjusted coefficients were larger than crude associations, not sensitive to modelling specifications, and statistically significant for highway proximity while of borderline significance for PM2.5 (P = 0.08). Annual CIMT progression among those living within 100 m of a highway was accelerated (5.5 micrometers/yr [95%CI: 0.13–10.79; p = 0.04]) or more than twice the population mean progression. For PM2.5, coefficients were positive as well, reaching statistical significance in the socially disadvantaged; in subjects reporting lipid lowering treatment at baseline; among participants receiving on-trial treatments; and among the pool of four out of the five trials.ConclusionConsistent with cross-sectional findings and animal studies, this is the first study to report an association between exposure to air pollution and the progression of atherosclerosis – indicated with CIMT change – in humans. Ostensibly, our results suggest that air pollution may contribute to the acceleration of cardiovascular disease development – the main causes of morbidity and mortality in many countries. However, the heterogeneity of the volunteering populations across the five trials, the limited sample size within trials and other relevant subgroups, and the fact that some key findings reached statistical significance in subgroups rather than the sample precludes generalizations to the general population.

Air Pollution and Cardiovascular Disease

“…coronary calcium and ankle brachial index (Diez Roux et al 2008). A recent study demonstrates that long-term PM exposure is not only related to the degree, but also to a faster progression rate of atherosclerosis (Kunzli et al 2010). Along with this epidemiological evidence, experimental research also established a link between exposure to PM and the development of atherosclerosis.…”

A rapid assessment of the impact of hazard reduction burning around Sydney, May 2016

“…These biomarkers have been consistently linked to subsequent cardiovascular disease and death. Long-term exposure has also been associated with preclinical markers of atherosclerosis (Künzli et al, 2005) and with progression (Künzli et al, 2010) of this pathology of high relevance to cardiovascular diseases. A series of studies from the German Heinz Nixdorf Recall Study has confirmed associations between various markers of atherosclerosis, including intima media thickness and coronary artery calcification, and the long-term average PM 2.5 concentration and proximity to traffic in Europe (Bauer et al, 2010;Hoffmann et al, 2006Hoffmann et al, , 2007.…”

Intravenous Administration of Multi‐walled Carbon Nanotubes Affects the Formation of Atherosclerosis in Sprague‐Dawley Rats

“…Still, considering that laboratory rats have the advantages of moderate body type, easy breeding, more offspring and low costs, using SD rats to develop AS is a simple and noninvasive method for generating an AS model. Epidemiological studies have shown that an important relationship exists between AS and exposure to particulate air pollution 1,25,26) . Moreover, Araujo et al reported that ultrafine particle (diameter<100 nm) exposures have a higher proatherogenic potential than fine particle exposures 27) .…”

“…Data from abundance studies well indicate that air particulate pollution is directly linked to the adverse cardiovascular outcomes in the general population 1) . Epidemiological studies have indicated that individuals suffering from cardiovascular disease have increased susceptibility to particulate matter and other air pollutants 2,3) .…”