Background/Aim: Older individuals often have increased health risks from environmental exposures, but this has been rarely investigated using molecular measurements of biological age. DNA methylation can be used to measure biological age and epigenetic age acceleration (EAA) in subjects. EAA accurately predicts mortality and chronic disease risk; however, it is unknown whether EAA modifies responses to environmental exposures. Here, we investigated whether cardiovascular and inflammatory responses to ozone are modified by EAA. Methods: LAMARCK was a controlled exposure study where 17 healthy participants were exposed to 0.3-ppm ozone or to clean air for two hours in a randomized single-blind crossover study design. Functional cardiopulmonary measures (n=3) and inflammation biomarkers (n=5) were collected immediately before and 24-hours after exposures. Epigenetic age was estimated using the Horvath method on cells that were collected from BALFs 24 hours after exposure. All outcomes were normalized to their pre-exposure values. We used mean and quantile regression to examine if EAA (calculated as epigenetic age – chronological age) measured during clean air exposure is associated with the estimated causal risk difference (CRD; Ozone – Clean Air) of cardiopulmonary and inflammatory outcomes. Regression models were evaluated with and without outliers to determine model consistency. Results are presented as percentage change relative to the mean value measured during air exposure. Results: Mean and median regression results were concordant. For mean regression, one-year higher EAA was associated with a 0.44% (95% confidence interval = 0.13%, 0.75%) increase in the CRD for QT interval in response to ozone exposure. One-year higher EAA was also associated with a -15.3% (95% confidence interval = -23.2%, -7.41%) change in the CRD for C-reactive protein in response to ozone. No other associations were observed. Conclusions: Accelerated aging in the lung is associated with prolonged QT interval and depressed inflammatory response during short-term ozone exposure.

Background/Aim: Fine particles (PM2.5) are associated with a higher risk for coronary events. Cardiac troponin T (cTnT) is a myocardium-specific protein which is measured clinically for the diagnosis and prognosis of myocardial infarction (MI). An elevation in circulating cTnT also occurs in non-ischemic conditions and indicates myocardial damage. We aimed to investigate short-term PM2.5 effects on cTnT and other myocardial injury-related biomarkers among participants undergoing cardiac catheterizations.Methods: This study included 7,497 plasma cTnT measurements conducted in 2,739 participants presenting to Duke University Hospital (2000 to 2012), partly alongside with measurements of C-reactive protein, fibrinogen, white blood cells, N-terminal-pro brain natriuretic peptide (NT-pro BNP), and partial oxygen pressure (PaO2). Daily PM2.5 was predicted by a neural network-based hybrid model at a 1km resolution and was assigned to participants' residential addresses. We applied generalized estimating equations to assess associations of PM2.5 with biomarker levels and the risk of a positive cTnT test (cTnT>0.1ng/mL).Results: Mean PM2.5 concentration was 11.8 μg/m3. Median plasma cTnT was 0.05 ng/mL and the prevalence of a positive cTnT test was 35.6% at presentation. For a 10µg/m3 increase in PM2.5 one day before cTnT measurement, plasma cTnT increased by 11.1% (95% CI: 5.3–17.4) and the odds ratio of a positive cTnT test was 1.12 (95% CI: 1.03–1.23). Participants under 60 years [20.9% (95% CI: 10.2–32.6)] or living in rural areas [17.6% (95% CI: 7.3–28.7)] had stronger associations. There was additionally evidence for positive associations of PM2.5 with fibrinogen and NT-pro BNP within one day after exposure, as well as negative associations with PaO2 at lag 3-4 days. Conclusions: Our study suggests that acute PM2.5 exposure may elevate indicators of myocardial injury and exertion, which substantiates the association of air pollution exposure with adverse cardiovascular events. This abstract does not necessarily represent EPA policy.

Background Both exposure to PM2.5 air pollution and neighborhood socioeconomic status (SES) are associated with adverse cardiovascular outcomes, including hypertension. We used the EPA-CARES electronic health record database to study the joint impact of neighborhood SES and PM2.5 exposure on hypertension among patients with heart failure in North Carolina. Methods We used block-group level factors of urbanicity, housing, and SES from the 2010 Census to identify seven neighborhood clusters (spatially noncontiguous) using Ward's hierarchical clustering algorithm. We then assigned neighborhood clusters to the primary residence of heart failure patients(N = 30,060). Participant residence-specific estimates of annual average PM2.5 concentrations were modeled at a 1x1 km resolution using a hybrid satellite-based model developed at Harvard University. We examined the associations between PM2.5 and hypertension, by neighborhood cluster and overall, using logistic regression models adjusted for age, sex, race, chronic kidney disease, diabetes, peripheral artery disease, hyperlipidemia, and chronic obstructive pulmonary disease. Results PM2.5 concentrations ranged from 9.5 µg/m3 (IQR 1.8 µg/m3) in lower-SES rural cluster to 10.4 µg/m3 (IQR 2.8 µg/m3) in upper-middle-SES urban cluster. We observed associations between a 1 µg/m3 increment in PM2.5 and hypertension among lower-SES urban (OR=1.05, 95% CI 1.00-1.10), lower-middle-SES urban (OR=1.03, 95% CI 1.00-1.07), and middle-SES urban (OR 1.04, 95% CI 0.98-1.10) clusters and overall (OR=1.02, 95% CI 1.00-1.04). We did not observe associations between PM2.5 and hypertension in rural, suburban, or upper-SES urban clusters. Conclusions Among heart failure patients, we observed associations between PM2.5 and hypertension in lower- and middle-SES urban areas. These results suggest that associations between PM2.5 and hypertension can vary by neighborhood among individuals with severe cardiovascular disease. This abstract does not necessarily reflect EPA policy.

We used a randomized crossover experiment to estimate the effects of ozone (vs. clean air) exposure on genome-wide DNA methylation of target bronchial epithelial cells, using 17 volunteers, each randomly exposed on two separated occasions to clean air or 0.3-ppm ozone for two hours. Twenty-four hours after exposure, participants underwent bronchoscopy to collect epithelial cells whose DNA methylation was measured using the Illumina 450 K platform. We performed global and regional tests examining the ozone versus clean air effect on the DNA methylome and calculated Fisher-exact p -values for a series of univariate tests. We found little evidence of an overall effect of ozone on the DNA methylome but some suggestive changes in PLSCR1 , HCAR1 , and LINC00336 DNA methylation after ozone exposure relative to clean air. We observed some participant-to-participant heterogeneity in ozone responses.

Cardiovascular disease accounts for over 17 million deaths per year. There is a large body of evidence suggesting that vitamin D deficiency is associated with cardiovascular disease and disease risk factors. In addition, researchers have found that exposures to ambient air pollution – particularly particulate matter (PM) – represent an added and independent risk factor for cardiovascular morbidity and mortality. Therefore, we wanted to assess whether vitamin D levels are associated with a heightened adverse cardiovascular response to diesel exhaust in healthy human subjects. Using a randomized, crossover study design, 13 healthy, young adults were exposed on two separate occasions to 300 µg/m3 diesel exhaust and filtered air under controlled conditions. Before, after, and 18 hrs following each exposure, blood samples were collected. The average vitamin D concentration before clean air exposures was 22.3 ng/mL, and the average vitamin D concentration before diesel exposures was 23.4 ng/mL (paired t-test; p = 0.44). Four participants were considered vitamin D deficient (vitamin D < 20 ng/mL), 7 participants had inadequate vitamin D levels (vitamin D between 21-29 ng/mL), and 2 were vitamin D sufficient (vitamin D > 30 ng/mL). Positive and significant associations were observed between baseline vitamin D concentrations and tPA (β = 6.93, 95% CI = -0.30, 13.57), while a negative and significant association was found with plasminogen (β = -2.84, 95% CI = -5.07, 0.61). At 0 hrs post exposure, there were significant negative associations between baseline vitamin D concentrations and D-dimer (β = 0.02, 95% CI = -0.04, 0.00) and IL-8 (β = -0.03, 95% CI = -0.06, 0.00). Additionally, at 18 hrs post exposure negative associations were found between baseline vitamin D concentrations and PAI-1 (β = -0.03, 95% CI = -0.07, 0.01) and TNF-α (β = -0.03, 95% CI = -0.06, 0.00). This suggests vitamin D deficiency might be associated with elevated cardiovascular responses.

Context: Exposure to particulate matter (PM) is associated with systemic health effects, but the cellular and molecular mechanisms are unclear. Objective: We hypothesized that, if circulating mononuclear cells play an important role in mediating systemic effects of PM, they would show gene expression changes following exposure. Materials and methods: Peripheral blood samples were collected before (0 h) and at 24 h from healthy subjects exposed to filtered air (FA) and ultrafine carbon particles (UFPs, 50 μg/m3) for 2 h in a previous study (n = 3 each). RNA from mononuclear cell fraction (>85% lymphocytes) was extracted, amplified and hybridized to Affymetrix HU133 plus 2 microarrays. Selected genes were confirmed in five additional subjects from the same study. Results: We identified 1713 genes (UFP 24 h vs. FA 0 and 24 h, P < 0.05, false discovery rate of 0.01). The top 10 upregulated genes (fold) were CDKN1C (1.86), ZNF12 (1.83), SRGAP2 (1.82), FYB (1.79), LSM14B (1.79), CD93 (1.76), NCSTN (1.70), DUSP6 (1.69), TACC1 (1.68), and H2AFY (1.68). Upregulation of CDKN1C and SRGAP2 was confirmed by real-time-PCR. We entered 1020 genes with a ratio >1.1 or <−1.1 into the Ingenuity Pathway Analysis and identified pathways related to inflammation, tissue growth and host defense against environmental insults, such as, insulin growth factor 1 signaling, insulin receptor signaling and NF-E2-related factor-2-mediated oxidative stress response pathway. Discussion and conclusions: Two-hour exposures to UFP produced gene expression changes in circulating mononuclear cells. These gene changes provide biologically plausible links to PM-induced systemic health effects, especially those in the cardiovascular system and glucose metabolism.