Residential Proximity to Major Roads, Exposure to Fine Particulate Matter, and Coronary Artery Calcium: The Framingham Heart Study

Long-term ambient air pollution and coronary atherosclerosis: Results from the Swedish SCAPIS study

BACKGROUND AND AIMS

Despite firm evidence for an association between long-term ambient air pollution exposure and cardiovascular morbidity and mortality, results from epidemiological studies on the association between air pollution exposure and atherosclerosis have not been consistent. We investigated associations between long-term low-level air pollution exposure and coronary atherosclerosis.

METHODS

We performed a cross-sectional analysis in the large Swedish CArdioPulmonary bioImaging Study (SCAPIS, n = 30 154), a random general population sample. Concentrations of total and locally emitted particulate matter <2.5 μm (PM2.5), <10 μm (PM10), and nitrogen oxides (NOx) at the residential address were modelled using high-resolution dispersion models. We estimated associations between air pollution exposures and segment involvement score (SIS), coronary artery calcification score (CACS), number of non-calcified plaques (NCP), and number of significant stenoses, using ordinal regression models extensively adjusted for potential confounders.

RESULTS

Median 10-year average PM2.5 exposure was 6.2 μg/m3 (range 3.5-13.4 μg/m3). 51 % of participants were women and 51 % were never-smokers. None of the assessed pollutants were associated with a higher SIS or CACS. Exposure to PM2.5 was associated with NCP (adjusted OR 1.34, 95 % CI 1.13, 1.58, per 2.05 μg/m3). Associations with significant stenoses were inconsistent.

CONCLUSIONS

In this large, middle-aged general population sample with low exposure levels, air pollution was not associated with measures of total burden of coronary atherosclerosis. However, PM2.5 appeared to be associated with a higher prevalence of non-calcified plaques. The results suggest that increased risk of early-stage atherosclerosis or rupture, but not increased total atherosclerotic burden, may be a pathway for long-term air pollution effects on cardiovascular disease.

Integrating 4-D light-sheet fluorescence microscopy and genetic zebrafish system to investigate ambient pollutants-mediated toxicity

Ambient air pollutants, including PM2.5 (aerodynamic diameter d ~2.5 μm), PM10 (d ~10 μm), and ultrafine particles (UFP: d < 0.1 μm) impart both short- and long-term toxicity to various organs, including cardiopulmonary, central nervous, and gastrointestinal systems. While rodents have been the principal animal model to elucidate air pollution-mediated organ dysfunction, zebrafish (Danio rerio) is genetically tractable for its short husbandry and life cycle to study ambient pollutants. Its electrocardiogram (ECG) resembles that of humans, and the fluorescent reporter-labeled tissues in the zebrafish system allow for screening a host of ambient pollutants that impair cardiovascular development, organ regeneration, and gut-vascular barriers. In parallel, the high spatiotemporal resolution of light-sheet fluorescence microscopy (LSFM) enables investigators to take advantage of the transparent zebrafish embryos and genetically labeled fluorescent reporters for imaging the dynamic cardiac structure and function at a single-cell resolution. In this context, our review highlights the integrated strengths of the genetic zebrafish system and LSFM for high-resolution and high-throughput investigation of ambient pollutants-mediated cardiac and intestinal toxicity.

Association of ambient PM10 and PM2.5 with coronary stenosis measured using selective coronary angiography

BACKGROUND

Long-term ambient particulate matter (PM) exposure exerts detrimental effects on cardiovascular health. Evidence on the relation of chronically exposed ambient PM10 and PM2.5 with coronary stenosis remains lacking. Our aim was to investigate the association of PM10 and PM2.5 with coronary stenosis in patients undergoing coronary angiography.

METHODS

We performed a retrospective cohort study consisting of 7513 individuals who underwent coronary angiography in Fujian Province, China, from January 2019 to December 2021. We calculated a modified Gensini score (GS) to represent the degree of stenosis in coronary arteries by selective coronary angiography. We fitted linear regressions and logistic models to assess the association of PM10 and PM2.5 with coronary stenosis. We employed restricted cubic splines to describe the exposure-response curves. We performed mediation analyses to assess the potential mediators.

RESULTS

Long-term ambient PM10 and PM2.5 (prior three years average) exposure was significantly associated with the GS, with a breakpoint concentration of 47.5 μg/m3 and 25.8 μg/m3 for PM10 and PM2.5, respectively, above which we found a linear positive exposure-response relationship of ambient PM with GS. Each 10 µg /m3 increase in PM10 exposure (β: 4.81, 95 % CI: 0.44-9.19) and PM2.5 exposure [β: 10.50, 95 % CI: 3.14-17.86] were positively related to the GS. The adjusted odds ratio (OR) for each 10 µg/m3 increment in PM10 exposure on severe coronary stenosis was 1.33 (95 % CI: 1.04-1.76). Correspondingly, the adjusted OR for PM2.5 was 1.87 (95 % CI: 1.24-2.99). The mediation analysis indicated that the effect of PM10 on coronary stenosis may be partially mediated through total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, serum creatinine and blood urea nitrogen, and the effect of PM2.5 may be mediated in part by hemoglobin A1c.

CONCLUSION

Our study provides the first evidence that chronic ambient PM10 and PM2.5 exposure was associated with coronary stenosis assessed by GS in patients with suspected coronary artery disease and reveals its potential mediators.

Fine particulate matter and cardiorespiratory health in China: A systematic review and meta-analysis of epidemiological studies

This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_2.5 published during the 13^th Five-Year Plan period (2016-2020) in China. Original articles published between January 1, 2016 and June 30, 2021 were searched in PubMed, Web of Science, the China National Knowledge Internet Database and Wanfang Database. Random- or fixed-effects models were used to pool effect estimates where appropriate. Of 8558 records identified, 145 met the full eligibility criteria. A 10 µg/m³ increase in short-term PM_2.5 exposure was significantly associated with increases of 0.70%, 0.86%, 0.38% and 0.96% in cardiovascular mortality, respiratory mortality, cardiovascular morbidity, and respiratory morbidity, respectively. The specific diseases with significant associations included stroke, ischemic heart disease, heart failure, arrhythmia, chronic obstructive pulmonary disease, pneumonia and allergic rhinitis. The pooled estimates per 10 µg/m³ increase in long-term PM_2.5 exposure were 15.1%, 11.9% and 21.0% increases in cardiovascular, stroke and lung cancer mortality, and 17.4%, 11.0% and 4.88% increases in cardiovascular, hypertension and lung cancer incidence respectively. Adverse changes in blood pressure, heart rate variability, systemic inflammation, blood lipids, lung function and airway inflammation were observed for either short-term or long-term PM_2.5 exposure, or both. Collectively, we summarized representative exposure-response relationships between short- and long-term PM_2.5 exposure and a wide range of cardiorespiratory outcomes applicable to China. The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries. Our findings are helpful for future standard revisions and policy formulation. There are still some notable gaps that merit further investigation in China.

Long-term exposure to air pollution, coronary artery calcification, and carotid artery plaques in the population-based Swedish SCAPIS Gothenburg cohort

Long-term exposure to air pollution is associated with cardiovascular events. A main suggested mechanism is that air pollution accelerates the progression of atherosclerosis, yet current evidence is inconsistent regarding the association between air pollution and coronary artery and carotid artery atherosclerosis, which are well-established causes of myocardial infarction and stroke. We studied associations between low levels of long-term air pollution, coronary artery calcium (CAC) score, and the prevalence and area of carotid artery plaques, in a middle-aged population-based cohort. The Swedish CArdioPulmonary bioImage Study (SCAPIS) Gothenburg cohort was recruited during 2013-2017 and thoroughly examined for cardiovascular risk factors, including computed tomography of the heart and ultrasonography of the carotid arteries. In 5070 participants (age 50-64 years), yearly residential exposures to air pollution (PM_2.5, PM₁₀, PM_coarse, NO_x, and exhaust-specific PM_2.5 1990-2015) were estimated using high-resolution dispersion models. We used Poisson regression to examine associations between long-term (26 years' mean) exposure to air pollutants and CAC score, and prevalence of carotid artery plaques, adjusted for potential confounders. Among participants with carotid artery plaques, we also examined the association with plaque area using linear regression. Mean exposure to PM_2.5 was low by international standards (8.5 μg/m³). There were no consistent associations between long-term total PM_2.5 exposure and CAC score or presence of carotid artery plaques, but an association between total PM_2.5 and larger plaque area in participants with carotid plaques. Associations with traffic-related air pollutants were consistently positive for both a high CAC score and bilateral carotid artery plaques. These associations were independent of road traffic noise. We found stronger associations among men and participants with cardiovascular risk factors. The results lend some support to atherosclerosis as a main modifiable pathway between low levels of traffic-related ambient air pollution and cardiovascular disease, especially in vulnerable individuals.

Long-term exposure to particulate air pollution and presence and progression of carotid artery plaques - A northern Sweden VIPVIZA cohort study

AIMS

To estimate the association between long-term exposure to particulate air pollution and sub-clinical atherosclerosis based on the existence of plaque and the carotid intima-media thickness (cIMT).

METHODS

Visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention (VIPVIZA) is a randomised controlled trial integrated within the Västerbotten Intervention Programme, an ongoing population-based cardiovascular disease (CVD) prevention programme in northern Sweden. Individuals aged 40, 50, or 60 years with one or more conventional CVD risk factors in Umeå municipality were eligible to participate. The 1425 participants underwent an ultrasound assessment of cIMT and plaque formation during the period 2013-2016 and at 3-year follow-up. Source-specific annual mean concentrations of particulate matter with aerodynamic diameter ≤10 μm (PM10) and ≤2.5 μm (PM2.5), and black carbon (BC) at the individual's residential address were modelled for the calendar years 1990, 2001 and 2011. Poisson regression was used to estimate prevalence ratios for presence of carotid artery plaques, and linear regression for cIMT.

RESULTS

The plaque prevalence was 43% at baseline and 47% at follow-up. An interquartile range (IQR) increase in PM10 (range in year 2011: 7.1-13.5 μg/m³) was associated with a prevalence ratio at baseline ultrasound of 1.11 (95% CI 0.99-1.25), 1.08 (95% CI 0.99-1.17), and 1.00 (95% CI 0.93-1.08) for lag 23, 12 and 2 years, and at follow-up 1.04 (95% CI 0.95-1.14), 1.08 (95% CI 1.00-1.16), and 1.01 (95% CI 0.95-1.08). Similar prevalence ratios per IQR were found for PM2.5 and BC, but with somewhat lower precision for the later. Particle concentrations were however not associated with the progression of plaque. No cross-sectional or longitudinal associations of change were found for cIMT.

CONCLUSIONS

This study of individuals with low/moderate risk for CVD give some additional support for an effect of long-term air pollution in early subclinical atherosclerosis.

Impacts of Environmental Insults on Cardiovascular Aging

PURPOSE OF REVIEW

With cardiovascular disease (CVD) being the top cause of deaths worldwide, it is important to ensure healthy cardiovascular aging through enhanced understanding and prevention of adverse health effects exerted by external factors. This review aims to provide an updated understanding of environmental influences on cardiovascular aging, by summarizing epidemiological and mechanistic evidence for the cardiovascular health impact of major environmental stressors, including air pollution, endocrine-disrupting chemicals (EDCs), metals, and climate change.

RECENT FINDINGS

Recent studies generally support positive associations of exposure to multiple chemical environmental stressors (air pollution, EDCs, toxic metals) and extreme temperatures with increased risks of cardiovascular mortality and morbidity in the population. Environmental stressors have also been associated with a number of cardiovascular aging-related subclinical changes including biomarkers in the population, which are supported by evidence from relevant experimental studies. The elderly and patients are the most vulnerable demographic groups to majority environmental stressors. Future studies should account for the totality of individuals' exposome in addition to single chemical pollutants or environmental factors. Specific factors most responsible for the observed health effects related to cardiovascular aging remain to be elucidated.

Links between chronic exposure to outdoor air pollution and cardiovascular diseases: a review

Acute exposure to air pollution is associated with an increasing risk of death and cardiovascular disorders. Nonetheless, the impact of chronic exposure to air pollution on the circulatory system is still debated. Here, we review the links of chronic exposure to outdoor air pollution with mortality and most common cardiovascular diseases, in particular during the coronavirus disease 2019 event (COVID-19). We found that recent studies provide robust evidence for a causal effect of chronic exposure to air pollution and cardiovascular mortality. In terms of mortality, the strongest relationship was noted for fine particulate matter, nitrogen dioxide, and ozone. There is also increasing evidence showing that exposure to air pollution, mainly fine particulate matter and nitrogen dioxide, is associated with the development of atherosclerosis, hypertension, stroke, and heart failure. However, available scientific evidence is not strong enough to support associations with cardiac arrhythmias and coagulation disturbances. Noteworthy, for some pollutants, the risk of negative health effects is high for concentrations lower than the limit values recommended by the European Union and Word Health Organization. Efforts to diminish exposure to air pollution and to design optimal methods of air pollution reduction should be urgently intensified and supported by effective legislation and interdisciplinary cooperation.

Trace element mass fractions in road dust as a function of distance from road

Road dust particles play an important role in atmospheric pollution and are associated with adverse human health effects. Traffic emissions are a major source of particles in road dust. However, there has been limited information about the relationship between distance from road and traffic-related elements levels in road dust. We investigated the relationships between proximity to the nearest major roadway and trace element mass fractions in PM₁₀ and PM_2.5 re-suspended from the road surface, based on measurements at three different distance ranges. We found that mass fractions of Ba, Cu, Zr, Zn, Cl, Co, Cr, Ca, Ti in PM₁₀ road dust as well as Zr, Cu, Cl, Zn, Cr, Ti, Mn, Ca, Ni, and Fe in PM_2.5 road dust, significantly decreased with distance from major road. Most of these elements are associated with road traffic emissions, including both tailpipe and non-tailpipe emissions. The decrease rates differed among elements due to differences in local traffic contributions. The decreases for elements which are mainly associated with non-tailpipe traffic emissions (e.g., Ba, Zr) were more dramatic. Our results indicate that traffic emissions, especially non-tailpipe emissions, contribute substantially to road dust, suggesting the need for control strategies for non-tailpipe emissions. Implications: We investigated the relationships between road proximity with trace element mass fractions in PM10 and PM2.5 re-suspended from the road surface. We observed significant decrease of traffic-related elements in PM10 and PM2.5 road dust with log distance from major road. We also found that the mass fractions for elements, which mainly come from traffic decrease more sharply compared to elements which come from both traffic and other sources. Our results indicate that traffic emissions contribute substantially to road dust, and imply that the distance to major road can be used as a proxy for ambient exposure.

Residential Proximity to Major Roadways and Prevalent Hypertension Among Older Women and Men: Results From the Chinese Longitudinal Healthy Longevity Survey

Background and Objectives: Prior studies suggested that residential proximity to major roadways was associated with increased risks of cardiovascular diseases in developed countries, for which one explanation is that road proximity could heighten the risks of hypertension. However, the association of residential distance to major roadways with hypertension is still unclear in low- and middle-income countries (LMICs) with levels of air pollution and socioeconomic development distinctively different from developed countries. Methods: We derived data from the eighth wave of the Chinese Longitudinal Healthy Longevity Survey, a nationwide prospective cohort. The present study included 12,881 individuals older than 65 years (mean age, 85.2 ± 11.7 years) with 55.8% of them being female. We ascertained the residential proximity to major roadways based on self-reports and hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg. We then used logistic regression to examine the association between residential distance to major roadways and hypertension. Results: The odds ratios (ORs) of hypertension for participants living 50 to 100, 101 to 200, and ≥200 meters from major roads were 1.17 [95% confidence interval (95% CI) = 1.02-1.33], 1.21 (95% CI = 1.05-1.41), and 1.22 (95% CI = 1.10-1.34), respectively, compared to those living within 50 m (P _{for trend} < 0.001). Significant effects of modifications from socioeconomic status and accessibility to health care resources were observed (Ps for interaction < 0.05). Compared to living within 50 m from a major roadway, the ORs of hypertension for living ≥50 m were higher in manual/agricultural workers, low-education groups, participants without household ventilation, and participants lacking in health education and health care resources. We observed considerable variations across geographic regions with the association in question attenuating in Eastern China but remaining significant in other regions. Conclusion: Residential proximity to major roadways was associated with lower odds of hypertension among older adults in China. The utility of residential proximity to major roadways as a marker of increased risks of hypertension and cardiovascular diseases may need to be revisited in LMICs.

Air Pollution and Progression of Atherosclerosis in Different Vessel Beds-Results from a Prospective Cohort Study in the Ruhr Area, Germany

OBJECTIVES

Due to inconsistent epidemiological evidence on health effects of air pollution on progression of atherosclerosis, we investigated several air pollutants and their effects on progression of atherosclerosis, using carotid intima media thickness (cIMT), coronary calcification (CAC), and thoracic aortic calcification (TAC).

METHODS

We used baseline (2000-2003) and 5-y follow-up (2006-2008) data from the German Heinz Nixdorf Recall cohort study, including 4,814 middle-aged adults. Residence-based long-term air pollution exposure, including particulate matter (PM) with aerodynamic diameter ≤2.5μm (PM2.5), (PM10), and nitrogen dioxide (NO2) was assessed using chemistry transport and land use regression (LUR) models. cIMT was quantified as side-specific median IMT assessed from standardized ultrasound images. CAC and TAC were quantified by computed tomography using the Agatston score. Development (yes/no) and progression of atherosclerosis (change in cIMT and annual growth rate for CAC/TAC) were analyzed with logistic and linear regression models, adjusting for age, sex, lifestyle variables, socioeconomic status, and traffic noise.

RESULTS

While no clear associations were observed in the full study sample (mean age 59.1 (±7.6) y; 53% female), most air pollutants were marginally associated with progression of atherosclerosis in participants with no or low baseline atherosclerotic burden. Most consistently for CAC, e.g., a 1.5 μg/m3 higher exposure to PM2.5 (LUR) yielded an estimated odds ratio of 1.19 [95% confidence interval (CI): 1.03, 1.39] for progression of CAC and an increased annual growth rate of 2% (95% CI: 1%, 4%).

CONCLUSION

Our study suggests that development and progression of subclinical atherosclerosis is associated with long-term air pollution in middle-aged participants with no or minor atherosclerotic burden at baseline, while overall no consistent associations are observed. https://doi.org/10.1289/EHP7077.

Ambient air pollution, traffic proximity and coronary atherosclerotic phenotype in China

BACKGROUND

Exposure to ambient air pollution is associated with cardiovascular risk, potentially via atherosclerosis promotion. The disease mechanisms underlying these associations remain uncertain.

OBJECTIVES

We aim to investigate the relationship of air pollution and traffic proximity with subclinical atherosclerosis, using coronary plaque phenotypes to gain insight into potential mechanisms.

METHODS

Coronary plaque total and component volumes, high-risk plaque (HRP) appearance, and luminal stenosis were characterized by coronary computed tomography angiography in 2279 patients with atherosclerosis at baseline between 2014 and 2017. Annual average exposure to air pollutants including fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) was estimated by air pollution models for individual participants. Multiple linear regression models were used to assess the association of each exposure with plaque phenotypes and coronary stenosis, controlling for potential confounders. Multiple logistic regression models were used to estimate associations with plaque vulnerability.

RESULTS

The studied population was 60.2±9.2 years old. PM_2.5 and NO₂ concentrations were significantly associated with a 5.0% (95%CI: 0.3, 9.9%, per 15 μg/m³ increase for PM_2.5), 12.0% (95%CI: 2.5, 22.5% per 20 μg/m³ for NO₂) larger volume of non-calcified plaque, respectively. Increase in O₃ concentration was associated with a 12.2% (95%CI: 2.2, 23.2%, per 5 μg/m³ O₃) larger volume of calcified plaque and a 12.8% (95%CI: 0.9, 26.2%) greater lumen narrowing. Increased PM_2.5 and NO₂, was also associated with increase in HRP, determined by the napkin ring sign (odds ratio: 1.41 [95%CI: 1.10, 1.80] for PM_2.5 and 1.78 [95%CI: 1.20, 2.63] for NO₂) and positive remodeling index (OR: 1.11 [95%CI: 1.01, 1.21] for PM_2.5 and 1.20 [95%CI: 1.02, 1.42] for NO₂), respectively, indicating increased plaque vulnerability.

CONCLUSION

Long-term exposures to air pollution were associated with greater plaque volume and luminal stenosis, and increased plaque vulnerability with attendant risk of plaque rupture and erosion.

Cigarette Smoke Exposure and Radiographic Pulmonary Vascular Morphology in the Framingham Heart Study

Rationale: Cigarette smoke exposure is a risk factor for many lung diseases, and histologic studies suggest that tobacco-related vasoconstriction and vessel loss plays a role in the development of emphysema. However, it remains unclear how tobacco affects the pulmonary vasculature in general populations with a typical range of tobacco exposure, and whether these changes are detectable by radiographic methods. Objectives: To determine whether tobacco exposure in a generally healthy population manifests as lower pulmonary blood vessel volumes and vascular pruning on imaging. Methods: A total of 2,410 Framingham Heart Study participants with demographic data and smoking history underwent volumetric whole-lung computed tomography from 2008 to 2011. Automated algorithms calculated the total blood volume of all intrapulmonary vessels (TBV), smaller peripheral vessels (defined as cross-sectional area <5 mm² [BV5]), and the relative fraction of small vessels (BV5/TBV). Tobacco exposure was assessed as smoking status, cumulative pack-years, and second-hand exposure. We constructed multivariable linear regression models to evaluate associations of cigarette exposure and pulmonary blood vessel volume measures, adjusting for demographic covariates, including age, sex, height, weight, education, occupation, and median neighborhood income. Results: All metrics of tobacco exposure (including smoking status, pack-years, and second-hand exposure) were consistently associated with higher absolute pulmonary blood vessel volume, higher small vessel volume, and/or higher small vessel fraction. For example, ever-smokers had a 4.6 ml higher TBV (95% confidence interval [CI] = 2.9-6.3, P < 0.001), 2.1 ml higher BV5 (95% CI = 1.3-2.9, P < 0.001), and 0.28 percentage-point-higher BV5/TBV (95% CI = 0.03-0.52, P = 0.03) compared with never-smokers. These associations remained significant after adjustment for percent predicted forced expiratory volume in 1 second, cardiovascular comorbidities, and did not differ based on presence or absence of airflow obstruction. Conclusions: Using computed tomographic imaging, we found that cigarette exposure was associated with higher pulmonary blood vessel volumes, especially in the smaller peripheral vessels. Although, histologically, tobacco-related vasculopathy is characterized by vessel narrowing and loss, our results suggest that radiographic vascular pruning may not be a surrogate of these pathologic changes.

Radiographic pulmonary vessel volume, lung function and airways disease in the Framingham Heart Study

Radiographic abnormalities of the pulmonary vessels, such as vascular pruning, are common in advanced airways disease, but it is unknown if pulmonary vascular volumes are related to measures of lung health and airways disease in healthier populations.In 2388 participants of the Framingham Heart Study computed tomography (CT) sub-study, we calculated total vessel volumes and the small vessel fraction using automated CT image analysis. We evaluated associations with measures of lung function, airflow obstruction on spirometry and emphysema on CT. We further tested if associations of vascular volumes with lung function were present among those with normal forced expiratory volume in 1 s and forced vital capacity.In fully adjusted linear and logistic models, we found that lower total and small vessel volumes were consistently associated with worse measures of lung health, including lower spirometric volumes, lower diffusing capacity and/or higher odds of airflow obstruction. For example, each standard deviation lower small vessel fraction (indicating more severe pruning) was associated with a 37% greater odds of obstruction (OR 1.37, 95% CI 1.11-1.71, p=0.004). A similar pattern was observed in the subset of participants with normal spirometry.Lower total and small vessel pulmonary vascular volumes were associated with poorer measures of lung health and/or greater odds of airflow obstruction in this cohort of generally healthy adults without high burdens of smoking or airways disease. Our findings suggest that quantitative CT assessment may detect subtle pulmonary vasculopathy that occurs in the setting of subclinical and early pulmonary and airways pathology.

Ambient air pollution exposure and risk and progression of interstitial lung abnormalities: the Framingham Heart Study

BACKGROUND

Ambient air pollution accelerates lung function decline among adults, however, there are limited data about its role in the development and progression of early stages of interstitial lung disease.

AIMS

To evaluate associations of long-term exposure to traffic and ambient pollutants with odds of interstitial lung abnormalities (ILA) and progression of ILA on repeated imaging.

METHODS

We ascertained ILA on chest CT obtained from 2618 Framingham participants from 2008 to 2011. Among 1846 participants who also completed a cardiac CT from 2002 to 2005, we determined interval ILA progression. We assigned distance from home address to major roadway, and the 5-year average of fine particulate matter (PM_2.5), elemental carbon (EC, a traffic-related PM_2.5 constituent) and ozone using spatio-temporal prediction models. Logistic regression models were adjusted for age, sex, body mass index, smoking status, packyears of smoking, household tobacco exposure, neighbourhood household value, primary occupation, cohort and date.

RESULTS

Among 2618 participants with a chest CT, 176 (6.7%) had ILA, 1361 (52.0%) had no ILA, and the remainder were indeterminate. Among 1846 with a preceding cardiac CT, 118 (6.4%) had ILA with interval progression. In adjusted logistic regression models, an IQR difference in 5-year EC exposure of 0.14 µg/m³ was associated with a 1.27 (95% CI 1.04 to 1.55) times greater odds of ILA, and a 1.33 (95% CI 1.00 to 1.76) times greater odds of ILA progression. PM_2.5 and O₃ were not associated with ILA or ILA progression.

CONCLUSIONS

Exposure to EC may increase risk of progressive ILA, however, associations with other measures of ambient pollution were inconclusive.

Investigation of air pollution and noise on progression of thoracic aortic calcification: results of the Heinz Nixdorf Recall Study

Aims

Air pollution and noise are potential risk factors for subclinical atherosclerosis. Longitudinal analyses, especially on the interplay of these environmental factors, are scarce and inconsistent. Hence we investigated long-term traffic-related exposure to air pollution and noise with the development and progression of thoracic aortic calcification, a marker of subclinical atherosclerosis.

Methods

We used baseline (2000–2003) and follow-up (2006–2008) data from the German Heinz Nixdorf Recall cohort study, including 4814 middle-aged adults. Residence-based air pollution (PM_2.5 (aerodynamic diameter ≤ 2.5 µm), PM₁₀, nitrogen dioxide and particle number), and noise was assessed with dispersion models. Thoracic aortic calcification was quantified from non-contrast enhanced electron beam computed tomography. The presence and extent of thoracic aortic calcification progression were analysed with multiple logistic and linear regression models, respectively, adjusting for age, sex, lifestyle variables, socioeconomic status and respective co-exposure.

Results

We observed no association in the full study sample (n = 3155, mean age 59.1 (±7.6) years, 52.8% women). While an interquartile range in particle number and night-time noise yielded odds ratios of 1.20 (1.03, 1.40) and 1.21 (1.00, 1.46) for binary thoracic aortic calcification progression, and 0.02 (–0.01, 0.05) and 0.04 (0.00, 0.07) higher growth rates of thoracic aortic calcification in participants with baseline thoracic aortic calcification less than 10, negative findings were observed in those with baseline thoracic aortic calcification of 10 or greater. Results were similar for other pollutants and daytime noise.

Conclusion

Our study shows no overall associations. Subgroup analyses suggest independent associations of traffic-related air pollution and noise with the development and progression of subclinical atherosclerosis in participants with no or minor thoracic aortic calcification at baseline, in contrast to negative findings in those with advanced calcification.

Association of Estimated Long-term Exposure to Air Pollution and Traffic Proximity With a Marker for Coronary Atherosclerosis in a Nationwide Study in China

IMPORTANCE

Epidemiologic evidence of the mechanisms of the association between long-term exposure to air pollution and coronary heart disease (CHD) is limited and relies heavily on studies performed in Europe and the United States, where air pollution levels are relatively low. In particular, the association between air pollution and CHD in patients with underlying risks for CHD is understudied.

OBJECTIVE

To determine whether air pollution and proximity to traffic are associated with the coronary artery calcium (CAC) score, a key atherosclerotic marker.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective, population-based cross-sectional study in a large-scale setting in China, 8867 consecutive patients aged 25 to 92 years with suspected CHD were recruited between November 17, 2015, and September 13, 2017. Participants were excluded if they had previous myocardial infarction, stenting, or coronary artery bypass grafting or incomplete risk factors and exposure data. Each participant underwent assessment of CAC and CHD risk factors at baseline. Data were analyzed from December 2017 to November 2018.

EXPOSURES

Annual means of fine particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5), nitrogen dioxide (NO2), and ozone (O3) were estimated at the participants' residences using a validated geostatistical prediction model. Exposure to a nearby roadway was also estimated.

MAIN OUTCOMES AND MEASURES

Computed tomography measurement of CAC score.

RESULTS

The mean (SD) age of the 8867 participants was 56.9 (10.4) years; 4378 (53.6%) were men. Annual mean (SD) PM2.5, NO2, and O3 measurements were 70.1 (20.0), 41.4 (14.7), and 93.9 (10.5) μg/m3, respectively. The mean (SD) CAC score was 91.4 (322.2) Agatston units. Exposure to PM2.5 and NO2, adjusting for CHD risk factors and multiple pollutants, were independently associated with increases in CAC scores of 27.2% (95% CI, 10.8% to 46.1%) per 30 μg/m3 PM2.5 and 24.5% (95% CI, 3.6% to 49.7%) per 20 μg/m3 NO2. For PM2.5, odds of both detectable CAC (Agatston score >0; odds ratio, 1.28; 95% CI, 1.13 to 1.45) and severe CAC (Agatston score >400; odds ratio, 1.59; 95% CI, 1.20 to 2.12) were increased. Associations of CAC with PM2.5 and NO2 were greater among male participants (PM2.5: 42.2%; 95% CI, 24.3% to 62.7%; NO2: 45.7%; 95% CI, 25.3% to 69.5%) and elderly participants (PM2.5: 50.1%; 95% CI, 28.8% to 75.0%; NO2: 55.5%; 95% CI, 31.8% to 83.6%) and those with diabetes (PM2.5: 62.2%; 95% CI, 30.9% to 101.0%; NO2: 31.2%; 95% CI, 13.9% to 51.0%). Independent association with CAC score was 9.0% (95% CI, -1.4% to 20.4%) for O3 per 15 μg/m3 and 2.4% (95% CI, -0.6% to 5.4%) for distance near roadway per 50% decrease.

CONCLUSIONS AND RELEVANCE

In this large Chinese study, long-term exposures to PM2.5 and NO2 were independently associated with severity of CAC. This finding may provide support for the pathophysiological role of coronary atherosclerosis through which air pollution exposure may be associated with CHD.

Aviation Noise and Cardiovascular Health in the United States: a Review of the Evidence and Recommendations for Research Direction

Purpose of the Review

In the USA, there is mounting pressure on aviation operators and regulators to address concerns about community impacts of aircraft noise given increasing evidence of adverse health impacts, continuing community complaints, availability of cost-effective programs to reduce exposures to aircraft noise, and more stringent international policies. In the USA, regulation of civil aviation noise is the responsibility of the Federal Aviation Administration (FAA), which requires a "significant body of scientific support," particularly applicable to the USA, to inform health-based policy and regulatory decisions. However, there have been very few studies investigating the relationship between noise and health in the USA and limited studies across the globe characterizing the effects of aviation noise specifically on cardiovascular health. This review focuses on recent findings on the relationship between aircraft noise and cardiovascular outcomes and directions for future research.

Recent Findings

Epidemiological studies generally report statistically significant associations between aircraft noise and adverse cardiovascular outcomes, although with limited evidence within the USA. Sleep disturbance, associated with nighttime noise, has been shown to be a risk factor for cardiovascular disease given associations with inflammatory markers and metabolic changes. Given numerous cardiovascular markers, the most appropriate choices depend on the ultimate objectives of the individual studies.

Summary

Given the state of the literature, future research should leverage emerging tools to estimate aviation, railway, and road traffic noise and apply noise estimates to a range of epidemiological study designs and endpoints to inform causal interpretation and help determine potential intervention strategies.

Aviation Noise and Cardiovascular Health in the United States: a Review of the Evidence and Recommendations for Research Direction

PURPOSE OF THE REVIEW

In the USA, there is mounting pressure on aviation operators and regulators to address concerns about community impacts of aircraft noise given increasing evidence of adverse health impacts, continuing community complaints, availability of cost-effective programs to reduce exposures to aircraft noise, and more stringent international policies. In the USA, regulation of civil aviation noise is the responsibility of the Federal Aviation Administration (FAA), which requires a "significant body of scientific support," particularly applicable to the USA, to inform health-based policy and regulatory decisions. However, there have been very few studies investigating the relationship between noise and health in the USA and limited studies across the globe characterizing the effects of aviation noise specifically on cardiovascular health. This review focuses on recent findings on the relationship between aircraft noise and cardiovascular outcomes and directions for future research.

RECENT FINDINGS

Epidemiological studies generally report statistically significant associations between aircraft noise and adverse cardiovascular outcomes, although with limited evidence within the USA. Sleep disturbance, associated with nighttime noise, has been shown to be a risk factor for cardiovascular disease given associations with inflammatory markers and metabolic changes. Given numerous cardiovascular markers, the most appropriate choices depend on the ultimate objectives of the individual studies.

SUMMARY

Given the state of the literature, future research should leverage emerging tools to estimate aviation, railway, and road traffic noise and apply noise estimates to a range of epidemiological study designs and endpoints to inform causal interpretation and help determine potential intervention strategies.

Exposure to Traffic Emissions and Fine Particulate Matter and Computed Tomography Measures of the Lung and Airways

BACKGROUND

Exposure to ambient air pollution has been associated with lower lung function in adults, but few studies have investigated associations with radiographic lung and airway measures.

METHODS

We ascertained lung volume, mass, density, visual emphysema, airway size, and airway wall area by computed tomography (CT) among 2,545 nonsmoking Framingham CT substudy participants. We examined associations of home distance to major road and PM2.5 (2008 average from a spatiotemporal model using satellite data) with these outcomes using linear and logistic regression models adjusted for age, sex, height, weight, census tract median household value and population density, education, pack-years of smoking, household tobacco exposure, cohort, and date. We tested for differential susceptibility by sex, smoking status (former vs. never), and cohort.

RESULTS

The mean participant age was 60.1 years (standard deviation 11.9 years). Median PM2.5 level was 9.7 µg/m (interquartile range, 1.6). Living <100 m from a major road was associated with a 108 ml (95% CI = 8, 207) higher lung volume compared with ≥400 m away. There was also a log-linear association between proximity to road and higher lung volume. There were no convincing associations of proximity to major road or PM2.5 with the other pulmonary CT measures. In subgroup analyses, road proximity was associated with lower lung density among men and higher odds of emphysema among former smokers.

CONCLUSIONS

Living near a major road was associated with higher average lung volume, but otherwise, we found no association between ambient pollution and radiographic measures of emphysema or airway disease.

Diesel exhaust exposure, its multi-system effects, and the effect of new technology diesel exhaust

Exposure to diesel exhaust (DE) from vehicles and industry is hazardous and affects proper function of organ systems. DE can interfere with normal physiology after acute and chronic exposure to particulate matter (PM). Exposure leads to potential systemic disease processes in the central nervous, visual, hematopoietic, respiratory, cardiovascular, and renal systems. In this review, we give an overview of the epidemiological evidence supporting the harmful effects of diesel exhaust, and the numerous animal studies conducted to investigate the specific pathophysiological mechanisms behind DE exposure. Additionally, this review includes a summary of studies that used biomarkers as an indication of biological plausibility, and also studies evaluating new technology diesel exhaust (NTDE) and its systemic effects. Lastly, this review includes new approaches to improving DE emissions, and emphasizes the importance of ongoing study in this field of environmental health.

Ambient air pollution, adipokines, and glucose homeostasis: The Framingham Heart Study

OBJECTIVE

To examine associations of proximity to major roadways, sustained exposure to fine particulate matter (PM2.5), and acute exposure to ambient air pollutants with adipokines and measures of glucose homeostasis among participants living in the northeastern United States.

METHODS

We included 5958 participants from the Framingham Offspring cohort examination cycle 7 (1998-2001) and 8 (2005-2008) and Third Generation cohort examination cycle 1 (2002-2005) and 2 (2008-2011), who did not have type 2 diabetes at the time of examination visit. We calculated 2003 annual average PM2.5 at participants' home address, residential distance to the nearest major roadway, and daily PM2.5, black carbon (BC), sulfate, nitrogen oxides (NOx), and ozone concentrations. We used linear mixed effects models for fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) which were measured up to twice, and used linear regression models for adiponectin, resistin, leptin, and hemoglobin A1c (HbA1c) which were measured only once, adjusting for demographics, socioeconomic position, lifestyle, time, and seasonality.

RESULTS

The mean age was 51years and 55% were women. Participants who lived 64m (25th percentile) from a major roadway had 0.28% (95% CI: 0.05%, 0.51%) higher fasting plasma glucose than participants who lived 413m (75th percentile) away, and the association appeared to be driven by participants who lived within 50m from a major roadway. Higher exposures to 3- to 7-day moving averages of BC and NOx were associated with higher glucose whereas the associations for ozone were negative. The associations otherwise were generally null and did not differ by median age, sex, educational attainment, obesity status, or prediabetes status.

CONCLUSIONS

Living closer to a major roadway or acute exposure to traffic-related air pollutants were associated with dysregulated glucose homeostasis but not with adipokines among participants from the Framingham Offspring and Third Generation cohorts.

Air Pollution and Cardiometabolic Disease: An Update and Call for Clinical Trials

Fine particulate matter <2.5 µm (PM2.5) air pollution is a leading cause of global morbidity and mortality. The largest portion of deaths is now known to be due to cardiovascular disorders. Several air pollutants can trigger acute events (e.g., myocardial infarctions, strokes, heart failure). However, mounting evidence additionally supports that longer-term exposures pose a greater magnified risk to cardiovascular health. One explanation may be that PM2.5 has proven capable of promoting the development of chronic cardiometabolic conditions including atherosclerosis, hypertension, and diabetes mellitus. Here, we provide an updated overview of recent major studies regarding the impact of PM2.5 on cardiometabolic health and outline key remaining scientific questions. We discuss the relevance of emerging trials evaluating personal-level strategies (e.g., facemasks) to prevent the harmful effects of PM2.5, and close with a call for large-scale outcome trials to allow for the promulgation of formal evidence-base recommendations regarding their appropriate usage in the global battle against air pollution.

Chromatin-modifying agents convert fibroblasts to OCT4+ and VEGFR-2+ capillary tube-forming cells

RATIONALE

The human epigenome is plastic. The goal of this study was to address if fibroblast cells can be epigenetically modified to promote neovessel formation.

METHODS AND RESULTS

Here, we used highly abundant human adult dermal fibroblast cells (hADFCs) that were treated with the chromatin-modifying agents 5-aza-2'-deoxycytidine and trichostatin A, and subsequently subjected to differentiation by activating Wnt signaling. Our results show that these epigenetically modified hADFCs increasingly expressed β-catenin, pluripotency factor octamer-binding transcription factor-4 (OCT4, also known as POU5F1), and endothelial cell (EC) marker called vascular endothelial growth factor receptor-2 (VEGFR-2, also known as Fetal Liver Kinase-1). In microscopic analysis, β-catenin localized to cell-cell contact points, while OCT4 was found to be localized primarily to the nucleus of these cells. Furthermore, in a chromatin immunoprecipitation experiment, OCT4 bound to the VEGFR-2/FLK1 promoter. Finally, these modified hADFCs also transduced Wnt signaling. Importantly, on a two-dimensional (2D) gel substrate, a subset of the converted cells formed vascular network-like structures in the presence of VEGF.

CONCLUSION

Chromatin-modifying agents converted hADFCs to OCT4+ and VEGFR-2+ capillary tube-forming cells in a 2D matrix in VEGF-dependent manner.

Residential proximity to major roads, exposure to fine particulate matter and aortic calcium: the Framingham Heart Study, a cohort study

OBJECTIVES

Traffic and ambient air pollution exposure are positively associated with cardiovascular disease, potentially through atherosclerosis promotion. Few studies have assessed associations of these exposures with thoracic aortic calcium Agatston score (TAC) or abdominal aortic calcium Agatston score (AAC), systemic atherosclerosis correlates. We assessed whether living close to a major road and residential fine particulate matter (PM_2.5) exposure were associated with TAC and AAC in a Northeastern US cohort.

DESIGN

Cohort study.

SETTING

Framingham Offspring and Third Generation participants residing in the Northeastern USA.

PARTICIPANTS AND OUTCOME MEASURES

Among 3506 participants, mean age was 55.8 years; 50% female. TAC was measured from 2002 to 2005 and AAC up to two times (2002-2005; 2008-2011) among participants from the Framingham Offspring or Third Generation cohorts. We first assessed associations with detectable TAC (logistic regression) and AAC (generalised estimating equation regression, logit link). As aortic calcium scores were right skewed, we used linear regression models and mixed-effects models to assess associations with natural log-transformed TAC and AAC, respectively, among participants with detectable aortic calcium. We also assessed associations with AAC progression. Models were adjusted for demographic variables, socioeconomic position indicators and time.

RESULTS

There were no consistent associations of major roadway proximity or PM_2.5 with the presence or extent of TAC or AAC, or with AAC progression. Some estimates were in the opposite direction than expected.

CONCLUSIONS

In this cohort from a region with relatively low levels of and variation in PM_2.5, there were no strong associations of proximity to a major road or PM_2.5 with the presence or extent of aortic calcification, or with AAC progression.

Residential Proximity to Major Roadways and Risk of Type 2 Diabetes Mellitus: A Meta-Analysis

Research indicates that higher levels of traffic-related pollution exposure increase the risk of diabetes, but the association between road proximity and diabetes risk remains unclear. To assess and quantify the association between residential proximity to major roadways and type 2 diabetes, a systematic review and meta-analysis was performed. Embase, Medline, and Web of Science were searched for eligible studies. Using a random-effects meta-analysis, the summary relative risks (RRs) were calculated. Bayesian meta-analysis was also performed. Eight studies (6 cohort and 2 cross-sectional) with 158,576 participants were finally included. The summary unadjusted RR for type 2 diabetes associated with residential proximity to major roadways was 1.24 (95% confidence interval [CI]: 1.07–1.44, p = 0.001, I² = 48.1%). The summary adjusted RR of type 2 diabetes associated with residential proximity to major roadways was 1.12 (95% CI: 1.03–1.22, p = 0.01, I² = 17.9%). After excluding two cross-sectional studies, the summary results suggested that residential proximity to major roadways could increase type 2 diabetes risk (Adjusted RR = 1.13; 95% CI: 1.02–1.27, p = 0.025, I² = 36.6%). Bayesian meta-analysis showed that the unadjusted RR and adjusted RR of type 2 diabetes associated with residential proximity to major roadways were 1.22 (95% credibility interval: 1.06–1.55) and 1.13 (95% credibility interval: 1.01–1.31), respectively. The meta-analysis suggested that residential proximity to major roadways could significantly increase risk of type 2 diabetes, and it is an independent risk factor of type 2 diabetes. More well-designed studies are needed to further strengthen the evidence.