Association between\nLong-Term Exposure to Traffic-Related\nAir Pollution and Cardio-Metabolic Phenotypes: An MRI Data-Based Analysis

Long-term exposure to traffic-related air pollution (TRAP)\nis associated\nwith cardiometabolic disease; however, its role in subclinical stages\nof disease development is unclear. Thus, we aimed to explore this\nassociation in a cross-sectional analysis, with cardiometabolic phenotypes\nderived from magnetic resonance imaging (MRI). Phenotypes of the left\n(LV) and right cardiac ventricle, whole-body adipose tissue (AT),\nand organ-specific AT were obtained by MRI in 400 participants of\nthe KORA cohort. Land-use regression models were used to estimate\nresidential long-term exposures to TRAP, e.g., nitrogen dioxides (NO<sub>2</sub>) or particle number concentration (PNC). Associations between\nTRAP and MRI phenotypes were modeled using linear regression. Participants’\nmean age was 56 ± 9 years, and 42% were female. Long-term exposure\nto TRAP was associated with decreased LV wall thickness; a 6.0 μg/m<sup>3</sup> increase in NO<sub>2</sub> was associated with a −1.9%\n[95% confidence interval: −3.7%; −0.1%] decrease in\nmean global LV wall thickness. Furthermore, we found associations\nbetween TRAP and increased cardiac AT. A 2,242 n/cm<sup>3</sup> increase\nin PNC was associated with a 4.3% [−1.7%; 10.4%] increase in\nmean total cardiac AT. Associations were more pronounced in women\nand in participants with diabetes. Our exploratory study indicates\nthat long-term exposure to TRAP is associated with subclinical cardiometabolic\ndisease states, particularly in metabolically vulnerable subgroups.