Abstract 15535: Particulate Matter Exposure Worsens Atherogenic Profile in “Ground Zero” Workers
Background: Exposure to particulate matter (PM) is associated with adverse health effects leading to increased morbidity. Law enforcement workers were exposed to high levels of particulate pollution after working at “Ground Zero” and may exhibit accelerated atherosclerosis. Peripheral artery tonometry (PAT) can evaluate vascular reactivity (surrogate for endothelial function). Dynamic contrast enhanced MRI (DCE-MRI) correlates with plaque neovascularization.
Hypothesis: We hypothesize that DCE-MRI and PAT can be used to evaluate differences in atherosclerosis profiles in patients subjected to high (initial dust cloud) and low (after 9/13/01) PM exposure.
Methods: 31 subjects (28 male) with high (n=19) or low (n=12) exposure to PM underwent PAT and DCE- MRI. Demographics (age, gender, family history, hypertension, diabetes, BMI, and smoking status), biomarkers (lipid profiles, hs-CRP, BP) and ankle-brachial index (ABI) measures (left and right) were obtained from all subjects. Differences between the high and low exposures were compared using independent samples t-test. Using linear forward stepwise regression with information criteria model, independent predictors of increased area under curve (AUC) from DCE were determined using all variables as input. Confidence interval of 95% was used and variables with p>0.1 were eliminated. p < 0.05 was considered significant.
Results: Subjects with high exposure (HE) had significantly lower PAT values (worse endothelial dysfunction) (PAT: 1.70 +/- 0.23 HE vs. 1.94 +/- 0.38 LE, p= 0.038), and higher DCE AUC uptake (increased neovascularization) compared to subjects with lower exposure(LE). (AUC: 2.65 +/- 0.63 HE vs. 1.88 +/- 0.69 LE, p = 0.016). Except for ABI of the right leg, none of the other parameters were significantly different between the two groups. Regression model indicated that only high exposure to PM, CRP >3.0 and total cholesterol were independently associated with increased neovascularization (in decreasing order of importance, all p < 0.026).
Conclusions: High exposure to PM decreases endothelial function, increases plaque neovascularization and thereby worsens atherogenic profile of “ground zero” workers.
- © 2011 by American Heart Association, Inc.