Long-term exposure to outdoor particulate matter and traffic-related air pollution are associated with accelerated atherosclerosis, according to data published in The Lancet.
Researchers conducted a prospective 10-year cohort study to measure progression of coronary artery calcium (CAC) and carotid artery intima-media thickness by CT in 6,795 participants from the Multi-Ethnic Study of Atherosclerosis and Air Pollution study. Ambient particulate matter less than 2.5 µm (PM2.5), nitrogen oxides (NOx), nitrogen dioxide and black carbon also were assessed.
The participants, aged 45 to 84 years, lived in six areas of the United States — Baltimore; Chicago; Los Angeles County; New York City; St. Paul, Minnesota; and Winston-Salem, North Carolina. Nearly 40% of the participants were white, 27% were black, 22% were Hispanic and 12% were Chinese.
The mean progression rate for CAC was 24 Agatston units per year (standard deviation, 58) and intima-media thickness was 12 µm per year (standard deviation, 10), according to the researchers.
After adjustment for potential confounders, a 5 µg/m3 higher PM2.5 concentration was linked to a 4.1 Agatston units per year (95% CI 1.4-6.8) increase in rate of CAC progression, according to the findings. In addition, a 40 parts per billion higher NOx concentration was associated with a 4.8 Agatston units per year (95% CI, 0.9-8.7) increased rate of CAC progression, and a 10 ppb higher nitrogen dioxide concentration was associated with a 2.7 Agatston units per year (95% CI, –0.3 to 5.7) increased rate of CAC progression.
An association between air pollution and intima-media thickness change, however, was not observed. The estimate for the effect of a 5 µg/m3 higher long-term exposure to PM2.5, in intima-media thickness was –0.9 µm per year (95% CI, –3 to 1.3).
“Evidence from this study provides strong biological support for the observation that long-term exposures to outdoor particulate matter and traffic-related exposures to outdoor particulate matter and traffic-related air pollution, specifically PM2.5 and NOx, are related to the development of atherosclerotic [CVD],” the researchers wrote. – by Tracey Romero
The researchers report no relevant financial disclosures.