Abstract
Rationale: Exposure to particulate matter <2.5μ in diameter (PM2.5) has been associated with increased mortality. After inhalation, PM2.5 may have direct effects on the pulmonary circulation. We hypothesized that PM2.5 exposure would be associated with pulmonary vascular changes on CT in a large population-based study.
Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants 45-84 years old without clinical cardiovascular disease. The MESA Lung Study measured total pulmonary vascular volume (TPVV) on non-contrast CT. TPVV is the sum of the volumes of arteries and veins (≥ approx. 1mm) per unit lung in the 2cm “peel” (Figure). Exposures to outdoor residential PM2.5 in the year prior to CT were estimated by a spatiotemporal model. Linear regression adjusted for age, sex, race, education, height, weight, smoking and scanner terms.
Results: Mean PM2.5 exposure of the 2675 participants (69±9 years, 47% male, 46% never smokers) was 11.1±1.5 μg/m3. Mean TPVV was 2.29 cm3 vessel/cm3 lung. In the fully adjusted model a 5 μg/m3 increase in PM2.5 was associated with an increase in TPVV (0.06 cm3 vessel/cm3 lung; P<0.001).
Conclusions: Exposure to PM2.5 was associated with increased TPVV, suggesting that PM2.5 may contribute to pulmonary vascular changes including microvascular damage.
- © 2014 ERS
