Author + information
- Ranjini M. Krishnan,
- Sara D. Adar,
- Adam A. Szpiro,
- Neal W. Jorgensen,
- Assaf P. Oron,
- Victor C. Van Hee,
- Marie S. O'Neill,
- R. Graham Barr,
- David M. Herrington,
- Joseph F. Polak and
- Joel D. Kaufman
Traffic related air pollution (TRAP) has been associated with increased atherosclerosis, left ventricular mass, myocardial infarction; endothelial dysfunction may mediate these effects. In the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), an interquartile (25th to 75th percentile change, IQR) increase in annual fine particulate matter concentrations (3µg/m3) was associated with a 0.3% decrease in flow-mediated dilation (FMD), a marker of endothelial dysfunction. We now evaluate the associations between endothelial function and measures of TRAP: residing near a major roadway, oxides of nitrogen (NOx) and black carbon (BC).
We evaluated brachial artery ultrasound data from 3,501 participants recruited from five states in 2000-2002, free of clinical cardiovascular disease, and aged 45-84 years; baseline arterial diameter (BAD) and FMD were measured to assess endothelial function. We defined proximity to traffic as living within 100m of a divided highway or within 50m of a state or county highway, derived from participants’ geocoded addresses. Long-term NOx (n=3049) and BC (n=2646) concentrations were estimated as annual average for each participant at the residence using a spatio-temporal model based on cohort-specific monitoring. Multivariate linear regression models tested the associations between the exposures and the outcomes after adjusting for demographics, traditional risk factors, medications, and sonographers.
An IQR increase in long-term BC concentrations (7 Mm-1) was associated with a 0.4% decrease in FMD (95% CI: −0.9 to 0.01%; P=0.06). An IQR increase in NOx (46 ppb) was associated with a 0.3 % decrease in FMD (95%CI: −0.5 to 0.05%; P=0.1). No associations were noted for BAD. Residential traffic proximity was not associated with FMD or BAD.
Long-term exposure to residential BC and NOx was associated with decreased endothelial function, but these findings were not statistically significant. Further research is needed to understand the toxicity of specific TRAP components on vascular function.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Prevention: Vitamin D, Omega 3 and Air Pollution
Abstract Category: 24. Prevention: Clinical
Presentation Number: 1273-4
- 2013 American College of Cardiology Foundation