Long-term ambient fine particulate matter and DNA methylation in inflammation pathways. - GreenMedInfo Summary
Long-term ambient fine particulate matter and DNA methylation in inflammation pathways: results from the Sister Study.
Epigenetics. 2019 Dec 10:1-12. Epub 2019 Dec 10. PMID: 31822152
Although underlying mechanisms of long-term exposure to air pollution and cardiovascular disease remain obscure, effects might partially act through changes in DNA methylation. We examined the associations between long-term ambient fine particulate matter (PM) and methylation, considering both a global measure and methylation at several specific inflammation-related loci, in two random sub-cohorts selected from a nationwide prospective study of US women. In one sub-cohort we measured; in the other, we measured methylation at three candidates CpG loci related to inflammatory pathways [() and()]. Annual average contemporaneous ambient PMconcentrations were estimated for the current residence. We used both classical least-squares and quantile regression models to estimate the long-term effects. The women in sub-cohorts 1 (n = 491) and 2 (n = 882) had mean ages of 55.8 and 56.7, respectively. Neither modelling approach showed an association between long-term PMandmethylation or between PMand either of the two CpG sites in. Using linear regression, there was an estimated change of -6.5% (95% confidence interval CI: -13.34%, 0.35%) in mean methylation ofper 5µg/mincrease in PM. Quantile regression showed that the downward shift was mainly in the lower half of the distribution of DNA methylation. Long-term residence in regions with higher ambient PMmay be associated with increased TNF-α through a reduction in methylation, particularly in the lower tail. Epigenetic markers and quantile regression might provide insight into mechanisms underlying the relationship between air pollution and cardiovascular disease.