Epigenetic influences on associations between air pollutants and lung function in elderly men: the normative aging study


Johanna Lepeule, Marie-Abele Catherine Bind, Andrea A Baccarelli, Petros Koutrakis, Letizia Tarantini, Augusto Litonjua, David Sparrow, Pantel Vokonas, and Joel D Schwartz. 2014. “Epigenetic influences on associations between air pollutants and lung function in elderly men: the normative aging study.” Environ Health Perspect, 122, 6, Pp. 566-72.


BACKGROUND: Few studies have been performed on pulmonary effects of air pollution in the elderly--a vulnerable population with low reserve capacity--and mechanisms and susceptibility factors for potential effects are unclear. OBJECTIVES: We evaluated the lag structure of air pollutant associations with lung function and potential effect modification by DNA methylation (< or ≥ median) at 26 individual CpG sites in nine candidate genes in a well-characterized cohort of elderly men. METHODS: We measured forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and blood DNA methylation one to four times between 1999 and 2009 in 776 men from the Normative Aging Study. Air pollution was measured at fixed monitors 4 hr to 28 days before lung function tests. We used linear mixed-effects models to estimate the main effects of air pollutants and effect modification by DNA methylation. RESULTS: An interquartile range (IQR) increase in subchronic exposure (3 to 28 days cumulated), but not in acute exposure (during the previous 4 hr, or the current or previous day), to black carbon, total and nontraffic particles with aerodynamic diameter ≤ 2.5 μm (PM2.5), carbon monoxide, and nitrogen dioxide was associated with a 1-5% decrease in FVC and FEV1 (p < 0.05). Slope estimates were greater for FVC than FEV1, and increased with cumulative exposure. The estimates slopes for air pollutants (28 days cumulated) were higher in participants with low (< median) methylation in TLR2 at position 2 and position 5 and high (≥ median) methylation in GCR. CONCLUSIONS: Subchronic exposure to traffic-related pollutants was associated with significantly reduced lung function in the elderly; nontraffic pollutants (particles, ozone) had weaker associations. Epigenetic mechanisms related to inflammation and immunity may influence these associations.
Last updated on 01/27/2022