Air Pollution Exposure and Pulmonary Vascular Morphology in the Framingham Heart Study

摘要

Background: Controlled exposure of rodents to particle pollution has been found to cause pulmonary arteriolar vasoconstriction and increased right ventricular pressure, but few studies have assessed if outdoor pollution exposure affects the pulmonary vasculature in generally healthy adults. Aims: To evaluate associations of long-term exposure to fine particulate matter (PM2.5), elemental carbon (EC, an indicator of combustion-related pollution), and distance to a major road with radiographic measures of pulmonary blood volume and distal vascular pruning among community-dwelling adults. Methods: We determined the total blood volume (TBV) of the pulmonary arterial and venous vasculature, and the percent of pulmonary blood volume in vessels with a cross-sectional area less than 5 mm2 (BV5%, a measure of distal vascular pruning), using an automated CT algorithm among 2,470 Framingham Heart Study chest CT sub-study participants from 2008-2011. We assigned distance to major roadway, average PM2.5 from 2004-2008 using a spatio-temporal model based on satellite data, and 2004-2008 average EC using a spatio-temporal prediction model using chemical transport data. Linear regression models of each exposure and TBV and BV5% were adjusted for age, sex, height, weight, cigarette smoking, second-hand tobacco, census tract median housing value, cohort (Offspring or 3rd Generation), and date of CT scan. Results: Mean (standard deviation, SD) TBV was 143.1 (31.0) mL and mean (SD) BV5% was 39.3 (4.1) %. Median (interquartile range, IQR) 5-year average exposure was 9.9 (1.3) pg/m3 for PM2.5 and 0.44 (0.14) ug/m3 for EC. In fully adjusted models, living close to a major road, and the 5-year average of PM2.5 and EC were not associated with TBV or BV5%. Conclusions: We did not observe any associations between exposure to traffic- and combustion-related pollution during adulthood and pulmonary vascular morphology on CT at contemporary pollution levels in the Northeastern United States.