Abstract 11443: Where NO 2 Meets Omega-3 Polyunsaturated Fatty Acids: Health Impact of Short-Term Ambient Air Pollution Exposure in Healthy Adults

Abstract

Introduction: Exposure to ambient nitrogen dioxide (NO 2 ) is associated with adverse respiratory and cardiovascular outcomes. Supplementation of omega-3 polyunsaturated fatty acids (PUFA) has shown health benefits against exposure to air pollution. Hypothesis: Dietary omega-3 PUFA intake offers cardiovascular and respiratory benefits against short-term exposure to ambient NO 2 in healthy adults. Methods: Sixty-two healthy participants were enrolled into low or high omega-3 groups based on their habitual dietary omega-3 PUFA intake. Each participant was repeatedly assessed for blood lipids, markers of coagulation and fibrinolysis, vascular function, heart rate variability (HRV), and lung function up to five times separated by at least 7 days between October 2016 and September 2019. Daily ambient NO 2 concentrations were obtained from nearby air quality monitoring stations. The associations between NO 2 concentrations and the measured biomarkers were evaluated using the linear mixed-effects models stratified by the omega-3 intake levels. Results: In the high omega-3 group, an IQR increase in NO 2 concentrations was associated with reductions in total cholesterol at lag2 [-2.6% (-4.4, -0.9)], LDL at lag2 [-3.1% (-5.5, -0.7)], and HDL at lag1 [-2.4% (-4.4, -0.3)] and lag2 [-2.0% (-3.8, -0.1)]; increases in flow-mediated dilatation of brachial artery at lag1[5.7% (0.1, 11.2)] and lag2 [5.7% (0.8, 10.6)]; decreases in plasma levels of endothelin-1at lag3 [-25.6% (-50.0, -1.2)] and lag4 [-22.9% (-45.9, -0.01)]; decreased high frequency (HFn) of HRV [-7.2% (-13.6, -0.8)] and increased LF/HF ratio [13.4% (0.2, 28.3)] at lag3; as well as increased lung function. In the low omega-3 group, blood lipids, vascular function biomarkers and lung function were not significantly associated with NO 2 exposure. However, NO 2 exposure was associated with elevations in coagulation markers (von Willebrand Factor and D-dimer) and a decrease in very-low frequency of HRV at lag0 in the low omega-3 group. Conclusions: The results imply that high dietary omega-3 PUFA intake may offer benefits to cardiovascular and respiratory health in response to exposure to low-level ambient NO 2 in healthy adults. THIS ABSTRACT OF A PROPOSED PRESENTATION DOES NOT NECESSARILY REFLECT EPA POLICY.