The association of air pollutants exposure with subclinical inflammation and carotid atherosclerosis.

BACKGROUND

Air pollution is a well-described environmental factor with evidence suggesting a firm association with cardiovascular diseases. The purpose of this study was to determine the association of exposure to gaseous air pollutants on atherosclerosis burden.

METHODS

1955 inhabitants of the Corinthia region, aged 40 years or older, underwent clinical and biochemical assessment as well as carotid ultrasonography to evaluate carotid intima-media thickness (cIMT) and plaque burden. Analyzers recording time series concentration of CO, NO2, and SO2 were located at 4 different open sites (Regions 1, 2, 3 and 4) based on their proximity to industries, highways or shipyards.

RESULTS

A higher concentration of CO, NO2, and SO2 was observed in Region 4 compared to the other regions. Mean cIMT (Region 1: 0.93 ± 0.24 mm; Region 2: 0.96 ± 0.40 mm; Region 3: 0.94 ± 0.39 mm; Region 4: 1.14 ± 0.55 mm, p < 0.001), maximum cIMT (p < 0.001) as well as carotid plaque burden (Region 1: 13.3%; Region 2: 18.8%; Region 3: 22.4%; Region 4: 38.6%, p < 0.001) were significantly higher in individuals of Region 4. Inhabitants of Region 4 had also higher levels of C reactive protein (Region 1: 4.56 ± 4.85 mg/l; Region 2: 3.49 ± 4.46 mg/l; Region 3: 4.03 ± 3.32 mg/l, Region 4: 5.16 ± 8.26 mg/l, p < 0.001). Propensity score analysis revealed higher inter-area differences in mean cIMT of individuals with coronary artery disease (CAD) (high vs low air pollution area: 1.56 ± 0.80 mm; vs. 1.18 ± 0.54 mm, p < 0.001) while there was no difference in cIMT of the matched population without CAD (p = 0.52).

CONCLUSIONS

An increased carotid atherosclerotic and inflammatory burden is observed in inhabitants of areas with the highest concentration of air pollutants.