ERIN O'BRIEN
Gene-environment interactions in the Multi-Ethnic Study of Atherosclerosis and Air Pollution
(MESA Air)
Environmental and Occupational Health, MPH
Preceptor: Joel Kaufman, MD, MPH
Numerous studies have shown a link between chronic exposure to air pollution and cardiovascular morbidity and mortality. The mechanisms underlying these associations are not yet understood, however. Vascular reactivity and arterial stiffness may play a role, and individual genetic differences in susceptibility to the effects of air pollution on these outcomes may provide insight into the biological pathways through which air pollution exerts its adverse effects on cardiovascular health. In a cross-sectional study using data from all MESA participants on whom genotype data was available and who underwent carotid ultrasound at Exam 1, we examined whether single nucleotide polymorphisms (SNPs) in genes involved in vascular reactivity and tone modify the effects of air pollution exposure on carotid arterial stiffness. We explored possible gene-environment interactions and used multiple linear regression to model the relationship between genotype and air pollution exposure (measured by participant residential proximity to major roadways) in relation to alterations in carotid distensibility, controlling for potential confounders and including interaction terms for genotype and air pollution exposure variables. Living within 150 meters of a major roadway was associated with a 4% decrease in carotid distensibility (95% CI: 6.8, 1.0), after adjustment for age, gender, race/ethnicity, smoking status, hypertension, education, income, systolic blood pressure, and body mass index. In an exploratory analysis, numerous SNPs in genes involved in the renin-angiotensin system modified the effect of residential proximity to a major roadway on carotid distensibility, suggesting these genes may play in role in the mechanistic pathway by which air pollution affects cardiovascular health.
