Air pollution, obesity, genes and cellular adhesion molecules

Objectives Particulate matter has been associated with acute cardiovascular outcomes, but our understanding of the mechanism is incomplete. We examined the association between particulate matter and cell adhesion molecules. We also investigated the modifying effect of genotype and phenotype variation to gain insight into the relevant biological pathways for this association. Methods We used mixed regression models to examine the association of PM(2.5) (particulate matter <= 2.5 mu m in diameter) and black carbon with serum concentrations of soluble intercellular adhesion molecule (sICAM-1) and soluble vascular cell adhesion molecule (sVCAM-1), markers of endothelial function and inflammation, in a longitudinal study of 809 participants in the Normative Ageing Study (1819 total observations). We also examined whether this association was modified by genotype, obesity or diabetes status. Genes selected for analyses were either related to oxidative stress, endothelial function, lipid metabolism or metal processing. Results Black carbon during the 2 days prior to blood draw was significantly associated with increased sVCAM-1 (4.5% increase per 1 mu g/m(3), 95% CI 1.1 to 8.0). Neither pollutant was associated with sICAM-1. Larger effects of black carbon on sVCAM were seen in subjects with obesity (p=0.007) and who were GSTM1 null (p=0.02). Conclusions Black carbon is associated with markers of endothelial function and inflammation. Genes related to oxidative defence may modify this association.