Abstract 1184: Urban Particulate Matter Air Pollution is Associated With Subclinical Atherosclerosis: Results From the Heinz Nixdorf Recall Study
Background Experimental and epidemiological evidence suggests that long-term air pollution contributes to atherogenesis, but epidemiological findings are still inconclusive. We examine the association of long-term exposure to fine particles with the carotid intima-media thickness (CIMT), a marker of subclinical atherosclerosis.
Methods We used baseline data (2000 –2003) from the Heinz Nixdorf Recall Study, a population-based cohort of 4814 participants, aged 45 to 75 years, living in 3 adjacent cities in Germany. We modeled daily mass concentrations of fine particles (PM2.5) on a grid of 1 km2 with a chemistry transport model. The average of the 365 daily values at the residential address prior to the examination date was used as a marker of long-term exposure. CIMT was measured over 1 cm proximal to the bifurcation on the far wall of the common carotid artery on both sides and averaged for analysis. We estimated the percent increase in mean CIMT for an increase in PM2.5 from the 10th to the 90th percentile with multiple linear regression, adjusting for city of residence, age, gender, active and passive smoking, socioeconomic status, body-mass index, alcohol intake, physical activity and diabetes.
Results Long-term average PM2.5 concentration in the 3380 analyzed subjects ranged from 13.4 to 22.4 μg/m3 with a mean of 16.8 μg/m3. The average CIMT was 0.68 mm (SD 0.13 mm). An increase in PM2.5 by interdecile range (4.2 μg/m3) was associated with a 4.5% increase in CIMT (95% CI 2.11– 6.94%). The mean absolute increase of 0.03 mm corresponds approximately to 5 years of vascular aging. The association was stronger in women (5.34%, 95% CI 2.02– 8.76%) than in men (3.86%, 95% CI 0.45–7.40%) and was attenuated slightly when including potential intermediaries (hypertension, lipids) on the causal pathway in the analysis (3.99%, 95% CI 1.64 – 6.40%).
Discussion Our study shows an association of long-term exposure to fine PM air pollution with atherosclerosis. This finding strengthens the hypothesized role of fine PM as a risk factor for atherogenesis.