Air Pollution and Cardiovascular Disease: JACC State-of-the-Art Review

Can respirator face masks in a developing country reduce exposure to ambient particulate matter?

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM₁₀, PM_2.5, and PM₁ (PM ≤ 10, 2.5, and 1 μm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM₁₀, PM_2.5, and PM₁, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM₁₀ with a mean value of 94.6 μg m^-3 (minimum-maximum: 51.7-100.3 μg m^-3), whereas it filtered on average just 29.0 μg m^-3 (25.7-43.5 μg m^-3) of ambient PM_2.5 and 18.2 μg m^-3 (14.7-21.8 μg m^-3) of PM₁. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.

Impact of air quality on the gastrointestinal microbiome: A review

BACKGROUND

Poor air quality is increasingly associated with several gastrointestinal diseases suggesting a possible association between air quality and the human gut microbiome. However, details on this remain largely unexplored as current available research is scarce. The aim of this comprehensive rigorous review was to summarize the existing reports on the impact of indoor or outdoor airborne pollutants on the animal and human gut microbiome and to outline the challenges and suggestions to expand this field of research.

METHODS AND RESULTS

A comprehensive search of several databases (inception to August 9, 2019, humans and animals, English language only) was designed and conducted by an experienced librarian to identify studies describing the impact of air pollution on the human gut microbiome. The retrieved articles were assessed independently by two reviewers. This process yielded six original research papers on the animal GI gastrointestinal microbiome and four on the human gut microbiome. β-diversity analyses from selected animal studies demonstrated a significantly different composition of the gut microbiota between control and exposed groups but changes in α-diversity were less uniform. No consistent findings in α or β-diversity were reported among the human studies. Changes in microbiota at the phylum level disclosed substantial discrepancies across animal and human studies.

CONCLUSIONS

A different composition of the gut microbiome, particularly in animal models, is associated with exposure to air pollution. Air pollution is associated with various taxa changes, which however do not follow a clear pattern. Future research using standardized methods are critical to replicate these initial findings and advance this emerging field.

Involvement of fine particulate matter exposure with gene expression pathways in breast tumor and adjacent-normal breast tissue

BACKGROUND

Fine particulate matter (PM_2.5) has been associated with breast cancer specific mortality, particularly for women with Stage I cancer. We examined the biological pathways that are perturbed by PM_2.5 exposures by analyzing gene expression measurements from breast tissue specimens.

METHODS

The Nurses' Health Studies (NHS and NHSII) are prospective cohorts with archival breast tissue specimens from breast cancer cases. Global gene expression data were ascertained with the Affymetrix Glue Human Transcriptome Array 3.0. PM_2.5 was estimated using spatio-temporal models linked to participants' home addresses. All analyses were performed separately in tumor (n = 591) and adjacent-normal (n = 497) samples, and stratified by estrogen receptor (ER) status and stage. We used multivariable linear regression, gene-set enrichment analyses (GSEA), and the least squares kernel machine (LSKM) to assess whether 3-year cumulative average pre-diagnosis PM_2.5 exposure was associated with breast-tissue gene expression pathways among predominately Stage I and II women (90.7%) and postmenopausal (81.2%) women. Replication samples (tumor, n = 245; adjacent-normal, n = 165) were measured on Affymetrix Human Transcriptome Array (HTA 2.0).

RESULTS

Overall, no pathways in the tumor area were significantly associated with PM_2.5 exposure. Among 272 adjacent-normal samples from Stage I ER-positive women, PM_2.5 was associated with perturbations in the oxidative phosphorylation, protein secretion, and mTORC1 signaling pathways (GSEA and LSKM p-values <0.05); however, results were not replicated in a small set of replication samples (n = 80).

CONCLUSIONS

PM_2.5 was generally not associated with breast tissue gene expression though was suggested to perturb oxidative phosphorylation and regulation of proteins and cellular signaling in adjacent-normal breast tissue. More research is needed on the biological role of PM_2.5 that influences breast tumor progression.

Worrying decrease in hospital admissions for myocardial infarction during the COVID-19 pandemic

Background

How coronavirus 2019 (COVID-19) is affecting management of myocardial infarction is a matter of concern, as medical resources have been massively reorientated and the population has been in lockdown since 17 March 2020 in France.

Aims

To describe how lockdown has affected the evolution of the weekly rate of myocardial infarctions (non-ST-segment and ST-segment elevation) hospital admissions in Lyon, the second largest city in France. To verify the trend observed, the same analysis was conducted for an identical time window during 2018–2019 and for an unavoidable emergency, i.e. birth.

Methods

Based on the national hospitalisation database [Programme de médicalisation des systèmes d’information (PMSI)], all patients admitted to the main public hospitals for a principal diagnosis of myocardial infarction or birth during the 2nd to the 14th week of 2020 were included. These were compared with the average number of patients admitted for the same diagnosis during the same time window in 2018 and 2019.

Results

Before lockdown, the number of admissions for myocardial infarction in 2020 differed from that in 2018–2019 by less than 10%; after the start of lockdown, it decreased by 31% compared to the corresponding time window in 2018–2019. Conversely, the numbers of births remained stable across years and before and after the start of lockdown.

Conclusion

This study strongly suggests a decrease in the number of admissions for myocardial infarction during lockdown. Although we do not have a long follow-up to determine whether this trend will endure, this is an important warning for the medical community and health authorities.

Effects of Aging and Diet on Cardioprotection and Cardiometabolic Risk Markers

The prevalence of several diseases increases by age, including cardiovascular diseases, which are the leading cause of morbidity and mortality worldwide. Aging, as a complex process characterized by senescence, triggers various pathways, such as oxidative stress, systemic inflammation, metabolism dysfunction, telomere shortening, mitochondrial dysfunction and deregulated autophagy. A better understanding of the mechanisms underlying senescence may lead to the development of new therapeutic targets and strategies for age-related pathologies and extend the healthy lifespan. Modulating lifestyle risk factors and adopting healthy dietary patterns remain significant tools in delaying the aging process, decreasing age-associated comorbidities and mortality, increasing life expectancy and consequently, preventing the development of cardiovascular disease. Furthermore, such a strategy represents the most cost-effective approach, and the quality of life of the subjects may be significantly improved. An integrated, personalized approach targeting cardiometabolic aging and frailty is suggested in daily clinical practice. However, it should be initiated from an early age. Moreover, there is a need for further well designed and controlled studies in order to elucidate a link between the time of feeding, longevity and cardiovascular prevention. In the future, it is expected that the pharmacological treatment in cardioprotective management will be necessary, accompanied by equally important lifestyle interventions and adjunctive exercise.

Silica nanoparticles induce JNK-mediated inflammation and myocardial contractile dysfunction

Increasing environmental exposure to silica nanoparticles (SiNPs) and limited cardiotoxicity studies posed a challenge for the safety evaluation and management of these materials. This study aimed to explore the adverse effects and underlying mechanisms of subacute exposure to SiNPs on cardiac function in rats. Results from echocardiographic, ultrastructural and histopathological analysis found that SiNPs induced cardiac contractile dysfunction, accompanied by incomplete myocardial structures, disordered sarcomere segments, interstitial edema and myocyte apoptosis in heart. Levels of myocardial enzymes and inflammatory factors were markedly increased in both serum and heart tissue, accompanied by elevated levels of oxidative damage occurred in the hearts of SiNPs-treated rats. SiNPs significantly upregulated the expressions of inflammation and contraction-related proteins, including JNK, p-JNK, c-Jun, TF and PAR1. Lentivirus transfection of JNK shRNA showed the low-expression of JNK-facilitated F-actin and inhibited TF in the SiNPs-treated cardiomyocytes. Moreover, SiNPs activated the mRNA and protein levels of JNK/TF/PAR1 pathway, and these effects were significantly dampened after JNK knock down. Our results demonstrate that SiNPs trigger myocardial contractile dysfunction via JNK/TF/PAR1 signaling pathway.

Short-term exposure to air pollution and its interaction effects with two ABO SNPs on blood lipid levels in northern China: A family-based study

We examined the main effects of ambient particulate matters, as well as whether single-nucleotide polymorphisms (SNPs), located within ABO gene would modify the relationship. Data were collected from a family-based study conducted in Northern China. A generalized additive model with a Gaussian link and with each family as a stratum was applied to estimate the percentage change in blood lipid levels following a 10 μg/m³ increase in ambient particulate matter concentrations. Interaction analyses were conducted by including a cross-product term of PM_2.5 or PM₁₀ by SNP. Results showed that a 10 μg/m³ increase in Particulate matter with aerodynamic diameter <2.5 μm (PM_2.5) concentrations corresponded to the highest 0.010% (95% CI: 0.002%-0.018%), 0.018% (95% CI: 0.006%-0.029%), 0.019% (95% CI: 0.010%-0.029%) increase in total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), respectively and 0.005% (95% CI: 0.002%-0.008%) decrease in high density lipoprotein cholesterol (HDL-C)-to-LDL-C ratio. As for the PM₁₀, similar results were observed. Furthermore, our finding showed an interaction effect of PM₁₀ and rs505922/rs579459 C allele on TG. Specifically, individuals carrying the rs505922 and rs579459 T allele have higher TG concentrations following PM₁₀ exposure, with a 10 μg/m³ increase in PM₁₀ concentrations corresponding to the highest 0.028% and 0.034% increase in TG, respectively. In conclusion, short-term exposures to ambient particulate matters are associated with a higher blood lipid level, which can be modified by ABO polymorphism. The findings may be useful in identifying vulnerable population according to genetic background.

Cardiorespiratory responses to fine particles during ambient PM2.5 pollution waves: Findings from a randomized crossover trial in young healthy adults

BACKGROUND

PM_2.5 pollution waves (PPWs) are severe air pollution events with extremely high-level concentration of ambient PM_2.5. PPWs, such as haze days, were suggested to be associated with increased cardiopulmonary mortality and morbidity. However, the biological mechanism response to ambient PM_2.5 during PPWs is still unclear.

METHODS

A randomized crossover trial was conducted on 29 healthy young adults. Repeated health measurements were performed before, during and after two typical PPWs under filtered and sham indoor air purification, with a washout interval of at least 2 weeks. Health parameters including blood pressure (BP), pulmonary function, fractional exhaled nitric oxide (FeNO) and circulating biomarkers which reflect platelet activation, blood coagulation and systematic oxidative stress were measured.

RESULTS

Ambient PM_2.5 levels elevated apparently during PPWs. Under sham purification, significant increase in FeNO and soluble P-selectin (sP-selectin) and decreases in pulmonary function were observed from pre-PPWs period to during-PPWs period. The changes in health biomarkers as mentioned above became attenuated and insignificant under filtered condition. For instance, sP-selectin increased by 12.0% (95% CI: 3.8%, 20.8%) during-PPWs periods compared with pre-PPWs periods under sham purification, while non-significant change was observed under filtered condition. Significant associations between time-weighted personal PM_2.5 exposure and increased levels of health biomarkers including FeNO, sP-selectin, oxidized low-density lipoprotein (ox-LDL) and 8-isoprostane (8-isoPGF2α) were found.

CONCLUSION

PPWs could affect cardiopulmonary health through systematic oxidative stress, platelet activation and respiratory inflammation in healthy adults, and short-term indoor air purification could alleviate the adverse cardiopulmonary effects.

Obesity and cardiovascular disease in women

As the prevalence of obesity continues to grow worldwide, the health and financial burden of obesity-related comorbidities grows too. Cardiovascular disease (CVD) is clearly associated with increased adiposity. Importantly, women are at higher risk of CVD when obese and insulin resistant, in particular at higher risk of developing heart failure with preserved ejection fraction and ischemic heart disease. Increased aldosterone and mineralocorticoid receptor activation, aberrant estrogenic signaling and elevated levels of androgens are among some of the proposed mechanisms explaining the heightened CVD risk. In addition to traditional cardiovascular risk factors, understanding nontraditional risk factors specific to women, like excess weight gain during pregnancy, preeclampsia, gestational diabetes, and menopause are central to designing personalized interventions aimed to curb the epidemic of CVD. In the present review, we examine the available evidence supporting a differential cardiovascular impact of increased adiposity in women compared with men and the proposed pathophysiological mechanisms behind these differences. We also discuss women-specific cardiovascular risk factors associated with obesity and insulin resistance.

Associations of outdoor fine particulate air pollution and cardiovascular disease in 157 436 individuals from 21 high-income, middle-income, and low-income countries (PURE): a prospective cohort study

BACKGROUND

Most studies of long-term exposure to outdoor fine particulate matter (PM_2·5) and cardiovascular disease are from high-income countries with relatively low PM_2·5 concentrations. It is unclear whether risks are similar in low-income and middle-income countries (LMICs) and how outdoor PM_2·5 contributes to the global burden of cardiovascular disease. In our analysis of the Prospective Urban and Rural Epidemiology (PURE) study, we aimed to investigate the association between long-term exposure to PM_2·5 concentrations and cardiovascular disease in a large cohort of adults from 21 high-income, middle-income, and low-income countries.

METHODS

In this multinational, prospective cohort study, we studied 157 436 adults aged 35-70 years who were enrolled in the PURE study in countries with ambient PM_2·5 estimates, for whom follow-up data were available. Cox proportional hazard frailty models were used to estimate the associations between long-term mean community outdoor PM_2·5 concentrations and cardiovascular disease events (fatal and non-fatal), cardiovascular disease mortality, and other non-accidental mortality.

FINDINGS

Between Jan 1, 2003, and July 14, 2018, 157 436 adults from 747 communities in 21 high-income, middle-income, and low-income countries were enrolled and followed up, of whom 140 020 participants resided in LMICs. During a median follow-up period of 9·3 years (IQR 7·8-10·8; corresponding to 1·4 million person-years), we documented 9996 non-accidental deaths, of which 3219 were attributed to cardiovascular disease. 9152 (5·8%) of 157 436 participants had cardiovascular disease events (fatal and non-fatal incident cardiovascular disease), including 4083 myocardial infarctions and 4139 strokes. Mean 3-year PM_2·5 at cohort baseline was 47·5 μg/m³ (range 6-140). In models adjusted for individual, household, and geographical factors, a 10 μg/m³ increase in PM_2·5 was associated with increased risk for cardiovascular disease events (hazard ratio 1·05 [95% CI 1·03-1·07]), myocardial infarction (1·03 [1·00-1·05]), stroke (1·07 [1·04-1·10]), and cardiovascular disease mortality (1·03 [1·00-1·05]). Results were similar for LMICs and communities with high PM_2·5 concentrations (>35 μg/m³). The population attributable fraction for PM_2·5 in the PURE cohort was 13·9% (95% CI 8·8-18·6) for cardiovascular disease events, 8·4% (0·0-15·4) for myocardial infarction, 19·6% (13·0-25·8) for stroke, and 8·3% (0·0-15·2) for cardiovascular disease mortality. We identified no consistent associations between PM_2·5 and risk for non-cardiovascular disease deaths.

INTERPRETATION

Long-term outdoor PM_2·5 concentrations were associated with increased risks of cardiovascular disease in adults aged 35-70 years. Air pollution is an important global risk factor for cardiovascular disease and a need exists to reduce air pollution concentrations, especially in LMICs, where air pollution levels are highest.

FUNDING

Full funding sources are listed at the end of the paper (see Acknowledgments).

Oxidative stress pathways of air pollution mediated toxicity: Recent insights

Ambient air pollution is a leading environmental cause of morbidity and mortality globally with most of the outcomes of cardiovascular origin. While numerous mechanisms are proposed to explain the link between air pollutants and cardiovascular events, the evidence supports a role for oxidative stress as a critical intermediary pathway in the transduction of systemic responses in the cardiovascular system. Indeed, alterations in vascular function are a critical step in the development of cardiometabolic disorders such as hypertension, diabetes, and atherosclerosis. This review will provide an overview of the impact of particulate and gaseous pollutants on oxidative stress from human and animal studies published in the last five years. We discuss current gaps in knowledge and evidence to date implicating the role of oxidative stress with an emphasis on inhalational exposures. We conclude with the identification of gaps, and an exhortation for further studies to elucidate the impact of oxidative stress in air pollution mediated effects.

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Particulate matter air pollution is the leading risk factor for cardiovascular morbidity and mortality globally.

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Mechanisms of oxidative stress mediated pathways.

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How does lung inflammation crucial to inhalational exposure mediate systemic toxicity?

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Review of recent animal and human exposure studies providing insights into oxidative stress pathways.

Secondhand cigarette smoke induces increased expression of contractile endothelin receptors in rat coronary arteries via a MEK1/2 sensitive mechanism

OBJECTIVES

Cigarette smoke, a strong risk factor for cardiovascular diseases, upregulates contractile endothelin (ET) receptors in coronary arteries. The present study examined the effects of second hand cigarette smoke exposure on the contractile endothelin receptors and the role of the MEK1/2 pathway in rat coronary arteries. Design: Rats were exposed to secondhand smoke (SHS) for 8 weeks followed by intraperitoneal injection of a MEK1/2 inhibitor, U0126 daily for another 4 weeks. Contractile responses of isolated coronary arteries were recorded by a sensitive wire myograph. The receptor protein expression levels were examined by Western blotting. Results: The results showed that SHS in vivo caused increased expression of ET receptors ET_A and ET_B, and that the MEK1/2 blocker U0126 significantly reversed SHS exposure-increased ET_A-mediated contractile responses and protein levels. Similar alterations were observed in ET_B receptors. U0126 showed dose-dependent effects on SHS-induced response on contractile property and protein levels of the ET_B receptor. However, only the higher dose U0126 (15 mg/kg) had inhibitory effects on the ET_A receptor. Conclusions: Taken together, our data show that SHS increases contractile ET receptors and MEK1/2 pathway inhibitor offsets SHS exposure-induced ET_A and ET_B receptor upregulation in rat coronary arteries.

A Rapid Decrease in Stroke, Acute Coronary Syndrome, and Corresponding Interventions at 65 United States Hospitals Following Emergence of COVID-19

Background Following the emergence of coronavirus disease 2019 (COVID-19), early reports suggested a decrease in stroke and acute coronary syndrome (ACS). We sought to provide descriptive statistics for stroke and ACS from a sample of hospitals throughout the United States, comparing data from March 2020 to similar months pre-COVID. Methods We performed a retrospective analysis of 65 academic and community hospitals in the Vizient Clinical Data Base. The primary outcome is monthly count of stroke and ACS, and acute procedures for both, from February and March in 2020 compared to the same months in 2018 and 2019. Results are aggregated for all hospitals and reported by Census Region. Results We identified 51,246 strokes (42,780 ischemic, 8,466 hemorrhagic), 1,043 mechanical thrombectomies (MT), 836 tissue plasminogen activator (tPA) administrations, 36,551 ACS, and 3,925 percutaneous coronary interventions (PCI) for ACS. In February 2020, relative to February 2018 and 2019, hospitalizations with any discharge diagnosis of stroke and ACS increased by 9.8% and 12.1%, respectively, while in March 2020 they decreased 18.5% and 7.5%, relative to March 2018 and 2019. When only including hospitalizations with the primary discharge diagnosis of stroke or ACS, in March 2020 they decreased 17.6% and 25.7%, respectively. In March 2020, tPA decreased 3.3%, MT increased 18.8%, although in February 2020 it had increased 36.8%, and PCI decreased 14.7%. These decreases were observed in all Census regions. Conclusions Following greater recognition of the risks of COVID-19, hospitalizations with stroke and ACS were markedly diminished in a geographically diverse sample of United States hospitals. Because the most likely explanation is that some patients with stroke and ACS did not seek medical care, the underlying reasons for this decrease warrant additional study to inform public health efforts and clinical care during this and future pandemics.

Association of Long-Term Exposure to Particulate Matter and Ozone With Health Status and Mortality in Patients After Myocardial Infarction

BACKGROUND

Long-term exposure to particulate matter <2.5 µm in diameter (PM_2.5) and ozone has been associated with the development and progression of cardiovascular disease and, in the case of PM_2.5, higher cardiovascular mortality. Whether exposure to PM_2.5 and ozone is associated with patients' health status and quality of life is unknown. We used data from 2 prospective myocardial infarction (MI) registries to assess the relationship between long-term PM_2.5 and ozone exposure with health status outcomes 1 year after an MI.

METHODS AND RESULTS

TRIUMPH (Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction) and PREMIER (Prospective Registry Evaluating Myocardial Infarction: Events and Recovery) enrolled patients presenting with MI at 31 US hospitals between 2003 and 2008. One year later, patients were assessed with the disease-specific Seattle Angina Questionnaire, and 5-year mortality was assessed with the Centers for Disease Control's National Death Index. Individual patients' exposures to PM_2.5 and ozone over the year after their MI were estimated from the Environment Protection Agency's Fused Air Quality Surface Using Downscaling tool that integrates monitoring station data and atmospheric models to predict daily air pollution exposure at the census tract level. We assessed the association of exposure to ozone and PM_2.5 with 1-year health status and mortality over 5 years using regression models adjusting for age, sex, race, socioeconomic status, date of enrollment, and comorbidities. In completely adjusted models, higher PM_2.5 and ozone exposure were independently associated with poorer Seattle Angina Questionnaire summary scores at 1-year (β estimate per +1 SD increase =-0.8 [95% CI, -1.4 to -0.3; P=0.002] for PM_2.5 and -0.9 [95% CI, -1.3 to -0.4; P<0.001] for ozone). Moreover, higher PM_2.5 exposure, but not ozone, was independently associated with greater mortality risk (hazard ratio =1.13 per +1 SD [95% CI, 1.07-1.20; P<0.001]).

CONCLUSIONS

In our study, greater exposure to PM_2.5 and ozone was associated with poorer 1-year health status following an MI, and PM_2.5 was associated with increased risk of 5-year death.

Relationship between air pollution and hospitalizations for congestive heart failure in elderly people in the city of São Paulo

To evaluate the effects of air pollutants on hospitalizations of elderly people for congestive heart failure (CHF) in the city of São Paulo, stratified by sex, exploring lag structures, from 2000 to 2013. Ecological time series study using information on hospitalization of elderly patients for CHF (ICD-10th: I50) obtained from DATASUS for the city of São Paulo. Information on O₃, PM₁₀, NO₂, SO₂, CO, temperature and humidity was obtained from CETESB. Descriptive analyses, Pearson correlation, and generalized linear Poisson regression model were applied to estimate the effects of pollutants. The interquartile variations of O₃ (52.45 μg/m³), PM₁₀ (24.28 μg/m³), NO₂ (7.63 μg/m³), SO₂ (50.22 μg/m³), and CO (1.28 ppm) were associated with increased hospitalizations for CHF. Air pollutants continue to be a factor that contributes to the increase in the number of hospitalizations due to CHF.

Oxidative Stress: A Unifying Paradigm in Hypertension

The etiology of hypertension involves complex interactions among genetic, environmental, and pathophysiologic factors that influence many regulatory systems. Hypertension is characteristically associated with vascular dysfunction, cardiovascular remodelling, renal dysfunction, and stimulation of the sympathetic nervous system. Emerging evidence indicates that the immune system is also important and that activated immune cells migrate and accumulate in tissues promoting inflammation, fibrosis, and target-organ damage. Common to these processes is oxidative stress, defined as an imbalance between oxidants and antioxidants in favour of the oxidants that leads to a disruption of oxidation-reduction (redox) signalling and control and molecular damage. Physiologically, reactive oxygen species (ROS) act as signalling molecules and influence cell function through highly regulated redox-sensitive signal transduction. In hypertension, oxidative stress promotes posttranslational modification (oxidation and phosphorylation) of proteins and aberrant signalling with consequent cell and tissue damage. Many enzymatic systems generate ROS, but NADPH oxidases (Nox) are the major sources in cells of the heart, vessels, kidneys, and immune system. Expression and activity of Nox are increased in hypertension and are the major systems responsible for oxidative stress in cardiovascular disease. Here we provide a unifying concept where oxidative stress is a common mediator underlying pathophysiologic processes in hypertension. We focus on some novel concepts whereby ROS influence vascular function, aldosterone/mineralocorticoid actions, and immunoinflammation, all important processes contributing to the development of hypertension.

Intensive care admissions and outcomes associated with short-term exposure to ambient air pollution: a time series analysis

PURPOSE

Short-term exposure to outdoor air pollution has been positively associated with numerous measures of acute morbidity and mortality, most consistently as excess cardiorespiratory disease associated with fine particulate matter (PM_2.5), particularly in vulnerable populations. It is unknown if the critically ill, a vulnerable population with high levels of cardiorespiratory disease, is affected by air pollution.

METHODS

We performed a time series analysis of emergency cardiorespiratory, stroke and sepsis intensive care (ICU) admissions for the years 2008-2016, using data from the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS-APD). Case-crossover analysis was conducted to assess the relationship between air pollution and the frequency and severity of ICU admissions having adjusted for temperature, humidity, public holidays and influenza activity.

RESULTS

46,965 episodes in 87 separate ICUs were analysed. We found no statistically significant associations with admission counts. However, ICU admissions ending in death within 30 days were significantly positively associated with short-term exposure to PM_2.5 [RR 1.18, 95% confidence interval (CI) 1.02-1.37, per 10 µg/m³ increase]. This association was more pronounced in those aged 65 and over (RR 1.33, 95% CI 1.11-1.58, per 10 µg/m³).

CONCLUSIONS

Increased ICU mortality was associated with higher levels of PM_2.5. Larger studies are required to determine if the frequency of ICU admissions is positively associated with short-term exposure to air pollution.

Modifiable Cardiovascular Risk, Hematopoiesis, and Innate Immunity

Unhealthy diet, lack of exercise, psychosocial stress, and insufficient sleep are increasingly prevalent modifiable risk factors for cardiovascular disease. Accumulating evidence indicates that these risk factors may fuel chronic inflammatory processes that are active in atherosclerosis and lead to myocardial infarction and stroke. In concert with hyperlipidemia, maladaptive immune system activities can contribute to disease progression and increase the probability of adverse events. In this review, we discuss recent insight into how the above modifiable risk factors influence innate immunity. Specifically, we focus on pathways that raise systemic myeloid cell numbers and modulate immune cell phenotypes, reviewing hematopoiesis, leukocyte trafficking, and innate immune cell accumulation in cardiovascular organs. Often, relevant mechanisms that begin with lifestyle choices and lead to cardiovascular events span multiple organ systems, including the central nervous, endocrine, metabolic, hematopoietic, immune and, finally, the cardiovascular system. We argue that deciphering such pathways provides not only support for preventive interventions but also opportunities to develop biomimetic immunomodulatory therapeutics that mitigate cardiovascular inflammation.

Zygophyllum album saponins prevent atherogenic effect induced by deltamethrin via attenuating arterial accumulation of native and oxidized LDL in rats

The current study aimed to examine, for the first time, the relationship between exposure to deltamethrin (DLM) and atherogenic lipid profile disorders in adult Wistar rats, as well as, to verify the mechanism of the beneficial role of Zygophyllum album leaves extracts (ZALE). The experimental study was assessed using DLM (4 mg/kg b.w) either alone or co administered with ZALE (400 mg/kg b.w) orally for 90 days in rats. RP-HPLC-DAD-ESI-QTOF-MS was used to identify the bioactive metabolites present in ZALE. Plasmatic and aortic total cholesterol (TC), LDL-cholesterol (LDL-C), native LDL (LDL-apo B-100) and oxidized LDL (ox-LDL) were evaluated using auto-analyzer and a sandwich ELISA, respectively. The protein expressions of LDLR (native LDL receptor) and CD36 (Scavenger receptor class B) were evaluated in aorta or liver with a Western blot. The pathology has been confirmed with lipid stain (Oil Red O). Phytochemicals analysis revealed the presence of fifteen saponins in ZALE. Rats intoxicated with DLM revealed a significant increase in plasmatic and aortic lipid profile (TC, LDL-C, LDL-apo B-100 and ox-LDL), as well as, the concentration of the plasmatic cytokines include TNF-α, IL-2 and IL-6, compared to control. Hepatic native LDL and aortic CD36 receptor expression were increased in DLM treated group, however aortic LDL-R does not present any modification, when compared to control. The detected disturbances in lipid parameters were supported by Oil Red O applied. Due to their antioxidant activity, the bioactive compounds in ZALE as powerful agents able to prevent the pro-atherogenic effect observed in DLM-treated animals. These metabolites modulated most of inflammatory markers, prevented accumulation of lipid and lipoprotein biomarkers, regulated the major receptor regulators of hepatic cholesterol metabolism, as well as normalize lipid distribution in liver and aorta tissue.

Integrating evolution into medical education for women's health care practitioners

Evolution is a fundamental principle in biology; however, it has been neglected in medical education. We argue that an evolutionary perspective is especially important for women's health care providers, as selection will act strongly on reproductive parameters, and the biological costs of female reproduction are generally more resource expensive than for men (e.g. due to gestation and lactation) with greater effects on health and wellbeing. An evolutionary perspective is needed to understand antibiotic resistance, disease and health risks associated with mismatches between our evolved adaptations and current conditions, the importance of the microbiome and the maternal role in how infants acquire and develop their early-life microbiome (vaginal birth, lactation), and the importance of breastmilk as a biochemical signal from mothers to their babies. We present data that obstetrician-gynecologists' views regarding the inclusion of evolution within their training is generally positive, but many barriers are perceived. Requiring coursework in evolutionary biology with an emphasis on evolutionary medicine prior to enrollment in medical school may be a solution.

Exposure to ambient fine particulate matter is associated with changes in fasting glucose and lipid profiles: a nationwide cohort study

BACKGROUND

Ambient fine particulate matter is a rising concern for global public health. It was recently suggested that exposure to fine particulate matter may contribute to the development of diabetes and dyslipidaemia. This study aims to examine the potential associations of ambient particulate matter exposure with changes in fasting glucose and lipid profiles in Koreans.

METHOD

We used the data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC), a nationwide database representative of the Korean population. A total of 85,869 individuals aged ≥20 years were included. Multiple regression analyses were conducted to assess the associations between exposure to particulate matter and changes in fasting glucose and lipid profiles at 2-year intervals after adjusting for confounders.

RESULTS

Significant associations were observed between an increase in interquartile range for particulate matter < 2.5 μm in diameter (PM_2.5) and elevated levels of fasting glucose and low-density lipoprotein cholesterol (p for trend = 0.015 and 0.010, respectively), while no association for particulate matter sized 2.5-10 μm in diameter (PM_10-2.5) was noted after adjusting for the other covariates. Sub-group analyses showed stronger associations in individuals who were older (≥60 years) or physically inactive.

CONCLUSIONS

Fine particulate matter exposure affects worsening fasting glucose and low-density lipoprotein cholesterol levels, with no evidence of an association for coarse particulate matter.

Traffic-Related Air Pollution and Carotid Plaque Burden in a Canadian City With Low-Level Ambient Pollution

Background

The association between fine particulate matter and cardiovascular disease has been convincingly demonstrated. The role of traffic‐related air pollutants is less clear. To better understand the role of traffic‐related air pollutants in cardiovascular disease development, we examined associations between NO₂, carotid atherosclerotic plaque, and cardiometabolic disorders associated with cardiovascular disease.

Methods and Results

Cross‐sectional analyses were conducted among 2227 patients (62.9±13.8 years; 49.5% women) from the Stroke Prevention and Atherosclerosis Research Centre (SPARC) in London, Ontario, Canada. Total carotid plaque area measured by ultrasound, cardiometabolic disorders, and residential locations were provided by SPARC medical records. Long‐term outdoor residential NO₂ concentrations were generated by a land use regression model. Associations between NO₂, total carotid plaque area, and cardiometabolic disorders were examined using multiple regression models adjusted for age, sex, smoking, and socioeconomic status. Mean NO₂ was 5.4±1.6 ppb in London, Ontario. NO₂ was associated with a significant increase in plaque (3.4 mm² total carotid plaque area per 1 ppb NO₂), exhibiting a linear dose‐response. NO₂ was also positively associated with triglycerides, total cholesterol, and the ratio of low‐ to high‐density lipoprotein cholesterol (P<0.05). Diabetes mellitus mediated the relationship between NO₂ and total carotid plaque area (P<0.05).

Conclusions

Our results demonstrate that even low levels of traffic‐related air pollutants are linked to atherosclerotic plaque burden, an association that may be partially attributable to pollution‐induced diabetes mellitus. Our findings suggest that reducing ambient concentrations in cities with NO₂ below current standards would result in additional health benefits. Given the billions of people exposed to traffic emissions, our study supports the global public health significance of reducing air pollution.

Fine particulate air pollution and human mortality: 25+ years of cohort studies

Much of the key epidemiological evidence that long-term exposure to fine particulate matter air pollution (PM_2.5) contributes to increased risk of mortality comes from survival studies of cohorts of individuals. Although the first two of these studies, published in the mid-1990s, were highly controversial, much has changed in the last 25 + years. The objectives of this paper are to succinctly compile and summarize the findings of these cohort studies using meta-analytic tools and to address several of the key controversies. Independent reanalysis and substantial extended analysis of the original cohort studies have been conducted and many additional studies using a wide variety of cohorts, including cohorts constructed from public data and leveraging natural experiments have been published. Meta-analytic estimates of the mean of the distribution of effects from cohort studies that are currently available, provide substantial evidence of adverse air pollution associations with all-cause, cardiopulmonary, and lung cancer mortality.

Real-Ambient Particulate Matter Exposure-Induced Cardiotoxicity in C57/B6 Mice

It is generally accepted that exposure to particulate matter (PM) increases the risk of cardiovascular-related morbidity and mortality, though the exact mechanism behind this has yet to be elucidated. Oxidative stress plays a potentially important role in the mechanism of toxicity, with Nrf2 serving as a major antioxidant gene. In the current study, a Nrf2 knockout mouse model was used in combination with an individual ventilated cage (IVC)-based real-ambient PM exposure system to assess the potential cardiotoxicity induced by real-ambient PM exposure and the potential role of Nrf2 and related signaling in this endpoint. After 6- or 11-weeks exposure to PM, ICP-mass spectrometry was used to assess the metal depositions in the heart tissue following PM exposure. Functional and morphological changes in the hearts were investigated with echocardiography and histopathology, and oxidative stress levels were assessed with a serum malondialdehyde content assay. In the further mechanistic study, an RNA-seq technique was utilized to assess the gene transcription status in the hearts of C57/B6 mice exposed to PM with or without Nrf2 knockout. The expression levels of genes of interest were then further investigated with quantitative real-time PCR and western blotting. The results indicated that PM exposure resulted in significant elevation of sodium, potassium, selenium, and ferrum levels in mouse heart tissue. Meanwhile, significantly altered heart function and morphology were observed. Interestingly, Nrf2 knockout led to abolishment of PM-induced effects in several functional parameters but not the morphological changes. Meanwhile, elevated malondialdehyde content was observed in Nrf2 knockout animals. RNA-seq results revealed thousands of genes altered by PM exposure and/or Nrf2 knockout, and this affected several pathways, such as MAPK, phagosome, calcium signaling, and JAK-STAT. In subsequent molecular studies, enhanced nuclear translocation of Nrf2 was also observed following PM exposure, while the MAPK signaling pathway along with related JAK-STAT and TGF-β1 pathway genes, such as p38MAPK, AKT, TAK1, JAK1, STAT3, GRB2, TGFb1, and SMAD2, were confirmed to be affected by PM exposure and/or Nrf2 knockout. The data suggested that PM may induce cardiotoxicity in C57/B6 mice in which Nrf2 plays both protective and detrimental roles involving cardiac-related pathways, such as MAPK, JAK-STAT, and TGF-β1.

Loss of life expectancy from air pollution compared to other risk factors: a worldwide perspective

AIMS

Long-term exposure of humans to air pollution enhances the risk of cardiovascular and respiratory diseases. A novel Global Exposure Mortality Model (GEMM) has been derived from many cohort studies, providing much-improved coverage of the exposure to fine particulate matter (PM2.5). We applied the GEMM to assess excess mortality attributable to ambient air pollution on a global scale and compare to other risk factors.

METHODS AND RESULTS

We used a data-informed atmospheric model to calculate worldwide exposure to PM2.5 and ozone pollution, which was combined with the GEMM to estimate disease-specific excess mortality and loss of life expectancy (LLE) in 2015. Using this model, we investigated the effects of different pollution sources, distinguishing between natural (wildfires, aeolian dust) and anthropogenic emissions, including fossil fuel use. Global excess mortality from all ambient air pollution is estimated at 8.8 (7.11-10.41) million/year, with an LLE of 2.9 (2.3-3.5) years, being a factor of two higher than earlier estimates, and exceeding that of tobacco smoking. The global mean mortality rate of about 120 per 100 000 people/year is much exceeded in East Asia (196 per 100 000/year) and Europe (133 per 100 000/year). Without fossil fuel emissions, the global mean life expectancy would increase by 1.1 (0.9-1.2) years and 1.7 (1.4-2.0) years by removing all potentially controllable anthropogenic emissions. Because aeolian dust and wildfire emission control is impracticable, significant LLE is unavoidable.

CONCLUSION

Ambient air pollution is one of the main global health risks, causing significant excess mortality and LLE, especially through cardiovascular diseases. It causes an LLE that rivals that of tobacco smoking. The global mean LLE from air pollution strongly exceeds that by violence (all forms together), i.e. by an order of magnitude (LLE being 2.9 and 0.3 years, respectively).

Diversity of and initiatives for hypertension management in Asia-Why we need the HOPE Asia Network

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving "zero" cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia-specific features of hypertension and hypertension-related cardiovascular complications, which means that a region-specific approach is needed. White-coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white-coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia-specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology-based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region-wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.

PM2.5-induced inflammation and lipidome alteration associated with the development of atherosclerosis based on a targeted lipidomic analysis

Epidemiological studies have confirmed that PM_2.5 could contribute to the development of atherosclerosis accompanied with lipids dysregulation. However, the lipids biomarkers involved in this progress remain largely unknown. In this study, a targeted lipidomic approach was used to find out the possible lipid biomarkers involved in the development of atherosclerosis after PM_2.5 exposure or during a recovery period. Also, we assessed the pro-atherosclerosis effects of PM_2.5 and follow-up influence using pulse wave (PW) Doppler ultrasound, oil red O staining and H&E staining. The vascular stiffness was elevated after 2-month PM_2.5 exposure and might persist after 1-month recovery. While the lesions mostly concentrated in the aortic arch was significantly increased in 2-month PM_2.5 exposure group and remained an increasing trend after 1-month recovery. The expressions of pro-inflammatory cytokines detected by Mouse Inflammation Array were elevated after ApoE^-/- mice treated with PM_2.5 for 2-month and restored following 1-month recovery. Yet, IL-10 was significantly decreased during 1-month recovery. Additionally, the targeted lipidomic analysis demonstrated that cholesterol ester (CE), phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (SM) were significantly increased while lysophosphatidylethanolamine (LPE), lysophosphatidylcholine (LPC), diacylglycerol (DG), triacylglycerol (TG) were reduced after 2-month PM_2.5 exposure, indicating that PM_2.5 could disrupt glycerophospholipids, glycerolipids and sphingolipids metabolism. And a persistent impact of PM_2.5 on glycerophospholipids and glycerolipids metabolism was found after 1-month recovery. Our study demonstrated that PM_2.5-induced inflammation response might promote atherosclerotic lesions probably through lipid dysregulation, and the influence probably persisted after 1-month recovery.

The role of cities in reducing the cardiovascular impacts of environmental pollution in low- and middle-income countries

BACKGROUND

As low- and middle-income countries urbanize and industrialize, they must also cope with pollution emitted from diverse sources.

MAIN TEXT

Strong and consistent evidence associates exposure to air pollution and lead with increased risk of cardiovascular disease occurrence and death. Further, increasing evidence, mostly from high-income countries, indicates that exposure to noise and to both high and low temperatures may also increase cardiovascular risk. There is considerably less research on the cardiovascular impacts of environmental conditions in low- and middle-income countries (LMICs), where the levels of pollution are often higher and the types and sources of pollution markedly different from those in higher-income settings. However, as such evidence gathers, actions to reduce exposures to pollution in low- and middle-income countries are warranted, not least because such exposures are very high. Cities, where pollution, populations, and other cardiovascular risk factors are most concentrated, may be best suited to reduce the cardiovascular burden in LMICs by applying environmental standards and policies to mitigate pollution and by implementing interventions that target the most vulnerable. The physical environment of cities can be improved though municipal processes, including infrastructure development, energy and transportation planning, and public health actions. Local regulations can incentivize or inhibit the polluting behaviors of industries and individuals. Environmental monitoring can be combined with public health warning systems and publicly available exposure maps to inform residents of environmental hazards and encourage the adoption of pollution-avoiding behaviors. Targeted individual or neighborhood interventions that identify and treat high-risk populations (e.g., lead mitigation, portable air cleaners, and preventative medications) can also be leveraged in the very near term. Research will play a key role in evaluating whether these approaches achieve their intended benefits, and whether these benefits reach the most vulnerable.

CONCLUSION

Cities in LMICs can play a defining role in global health and cardiovascular disease prevention in the next several decades, as they are well poised to develop innovative, multisectoral approaches to pollution mitigation, while also protecting the most vulnerable.

Association of short-term exposure to air pollution with myocardial infarction with and without obstructive coronary artery disease

Background

Air pollution including particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5) increases the risk of acute myocardial infarction. However, whether short-term exposure to PM2.5 triggers the onset of myocardial infarction with nonobstructive coronary arteries, compared with myocardial infarction with coronary artery disease, has not been elucidated. This study aimed to estimate the association between short-term exposure to PM2.5 and admission for acute myocardial infarction, myocardial infarction with coronary artery disease, and myocardial infarction with nonobstructive coronary arteries.

Design

This was a time-stratified case-crossover study and multicenter validation study.

Methods

This study used a nationwide administrative database in Japan between April 2012–March 2016. Of 137,678 acute myocardial infarction cases, 123,633 myocardial infarction with coronary artery disease and 14,045 myocardial infarction with nonobstructive coronary arteries were identified by a validated algorithm combined with International Classification of Disease (10th revision), diagnostic, and procedure codes. Air pollutants and meteorological data were obtained from the monitoring station nearest to the admitting hospital.

Results

In spring (March–May), the short-term increase of 10 µg/m3 in PM2.5 2 days before admission was significantly associated with admission for acute myocardial infarction, myocardial infarction with nonobstructive coronary arteries, and myocardial infarction with coronary artery disease after adjustment for meteorological variables (odds ratio 1.060, 95% confidence interval 1.038–1.082; odds ratio 1.151, 1.079–1.227; odds ratio 1.049, 1.026–1.073, respectively), while the association was not significant in other variables. These associations were also observed after adjustment for other co-pollutants. The risk for myocardial infarction with nonobstructive coronary arteries (vs myocardial infarction with coronary artery disease) was associated with an even lower concentration of PM2.5 under the current environmental standards.

Conclusions

This study showed the seasonal difference of acute myocardial infarction risk attributable to PM2.5 and the difference in the threshold of triggering the onset of acute myocardial infarction subtype.

Air pollution and cardiovascular disease: car sick

The cardiovascular effects of inhaled particle matter (PM) are responsible for a substantial morbidity and mortality attributed to air pollution. Ultrafine particles, like those in diesel exhaust emissions, are a major source of nanoparticles in urban environments, and it is these particles that have the capacity to induce the most significant health effects. Research has shown that diesel exhaust exposure can have many detrimental effects on the cardiovascular system both acutely and chronically. This review provides an overview of the cardiovascular effects on PM in air pollution, with an emphasis on ultrafine particles in vehicle exhaust. We consider the biological mechanisms underlying these cardiovascular effects of PM and postulate that cardiovascular dysfunction may be implicated in the effects of PM in other organ systems. The employment of multiple strategies to tackle air pollution, and especially ultrafine particles from vehicles, is likely to be accompanied by improvements in cardiovascular health.

Nasal Microbiota Modifies the Effects of Particulate Air Pollution on Plasma Extracellular Vesicles

Air pollution exposure has been linked to modifications of both extracellular vesicle (EV) concentration and nasal microbiota structure (NMB), which might act as the respiratory health gatekeeper. This study aimed to assess whether an unbalanced NMB could modify the effect of particulate matter (PM) exposure on plasmatic EV levels. Due to two different NMB taxonomical profiles characterized by a widely different relative abundance of the Moraxella genus, the enrolled population was stratified into Mor- (balanced NMB) and Mor+ (unbalanced NMB) groups (Moraxella genus's cut-off ≤25% and >25%, respectively). EV features were assessed by nanoparticle tracking analysis (NTA) and flow-cytometry (FC). Multivariable analyses were applied on EV outcomes to evaluate a possible association between PM10 and PM2.5 and plasmatic EV levels. The Mor- group revealed positive associations between PM levels and plasmatic CD105+ EVs (GMR = 4.39 p = 0.02) as for total EV count (GMR = 1.92 p = 0.02). Conversely, the Mor+ group showed a negative association between exposure and EV outcomes (CD66+ GMR = 0.004 p = 0.01; EpCAM+ GMR = 0.005 p = 0.01). Our findings provide an insight regarding how a balanced NMB may help to counteract PM exposure effects in terms of plasmatic EV concentration. Further research is necessary to understand the relationship between the host and the NMB to disentangle the mechanism exerted by inhaled pollutants in modulating EVs and NMB.

Ambient Air Pollution Is Associated With HDL (High-Density Lipoprotein) Dysfunction in Healthy Adults

Objective- We aimed to assess whether exposure to higher levels of ambient air pollution impairs HDL (high-density lipoprotein) function and to elucidate the underlying biological mechanisms potentially involved. Approach and Results- In the Beijing AIRCHD study (Air Pollution and Cardiovascular Dysfunction in Healthy Adults), 73 healthy adults (23.3±5.4 years) were followed-up with 4 repeated study visits in 2014 to 2016. During each visit, ambient air pollution concentrations, HDL function metrics, and parameters of inflammation and oxidative stress were measured. Average daily concentrations of ambient particulate matter in diameter <2.5 μm were 62.9 µg/m³ (8.1-331.0 µg/m³). We observed significant decreases in HDL cholesterol efflux capacity of 2.3% (95% CI, -4.3 to -0.3) to 5.0% (95% CI, -7.6 to -2.4) associated with interquartile range increases in moving average concentrations of particulate matter in diameter <2.5 μm and traffic-related air pollutants (black carbon, nitrogen dioxide, and carbon monoxide) during the 1 to 7 days before each participant's clinic visit. Higher ambient air pollutant levels were also associated with significant reductions in circulating HDL cholesterol and apoA-I (apolipoprotein A-I), as well as elevations in HDL oxidation index, oxidized LDL (low-density lipoprotein), malondialdehyde, and high-sensitivity C-reactive protein. Conclusions- Higher ambient air pollution concentrations were associated with impairments in HDL functionality, potentially because of systemic inflammation and oxidative stress. These novel findings further our understanding of the mechanisms whereby air pollutants promote cardiometabolic disorders.

Vitamin D, Marine n-3 Fatty Acids, and Primary Prevention of Cardiovascular Disease Current Evidence

Whether marine omega-3 fatty acid (n-3 FA) or vitamin D supplementation can prevent cardiovascular disease (CVD) in general populations at usual risk for this outcome is unknown. A major goal of VITAL (Vitamin D and Omega-3 Trial) was to fill this knowledge gap. In this article, we review the results of VITAL, discuss relevant mechanistic studies regarding n-3 FAs, vitamin D, and vascular disease, and summarize recent meta-analyses of the randomized trial evidence on these agents. VITAL was a nationwide, randomized, placebo-controlled, 2×2 factorial trial of marine n-3 FAs (1 g/d) and vitamin D3 (2000 IU/d) in the primary prevention of CVD and cancer among 25 871 US men aged ≥50 and women aged ≥55 years, including 5106 blacks. Median treatment duration was 5.3 years. Supplemental n-3 FAs did not significantly reduce the primary cardiovascular end point of major CVD events (composite of myocardial infarction, stroke, and CVD mortality; hazard ratio [HR], 0.92 [95% CI, 0.80-1.06]) but were associated with significant reductions in total myocardial infarction (HR, 0.72 [95% CI, 0.59-0.90]), percutaneous coronary intervention (HR, 0.78 [95% CI, 0.63-0.95]), and fatal myocardial infarction (HR, 0.50 [95% CI, 0.26-0.97]) but not stroke or other cardiovascular end points. For major CVD events, a treatment benefit was seen in those with dietary fish intake below the cohort median of 1.5 servings/wk (HR, 0.81 [95% CI, 0.67-0.98]) but not in those above (P interaction=0.045). For myocardial infarction, the greatest risk reductions were in blacks (HR, 0.23 [95% CI, 0.11-0.47]; P interaction by race, 0.001). Vitamin D supplementation did not reduce major CVD events (HR, 0.97 [95% CI, 0.85-1.12]) or other cardiovascular end points. Updated meta-analyses that include VITAL and other recent trials document coronary risk reduction from supplemental marine n-3 FAs but no clear CVD risk reduction from supplemental vitamin D. Additional research is needed to determine which individuals may be most likely to derive net benefit from supplementation. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01169259.

Short-term exposure to ambient fine particulate matter and out-of-hospital cardiac arrest: a nationwide case-crossover study in Japan

BACKGROUND

PM_2·5 is an important but modifiable environmental risk factor, not only for pulmonary diseases and cancers, but for cardiovascular health. However, the evidence regarding the association between air pollution and acute cardiac events, such as out-of-hospital cardiac arrest (OHCA), is inconsistent, especially at concentrations lower than the WHO daily guideline (25 μg/m³). This study aimed to determine the associations between exposure to ambient air pollution and the incidence of OHCA.

METHODS

In this nationwide case-crossover study, we linked prospectively collected population-based registry data for OHCA in Japan from Jan 1, 2014, to Dec 31, 2015, with daily PM_2·5, carbon monoxide (CO), nitrogen dioxide (NO₂), photochemical oxidants (O_x), and sulphur dioxide (SO₂) exposure on the day of the arrest (lag 0) or 1-3 days before the arrest (lags 1-3), as well as the moving average across days 0-1 and days 0-3. Daily exposure was calculated by averaging the measurements from all PM_2·5 monitoring stations in the same prefecture. The effect of PM_2·5 on risk of all-cause or cardiac OHCA was estimated using a time-stratified case-crossover design coupled with conditional logistic regression analysis, adjusted for daily temperature and relative humidity. Single-pollutant models were also investigated for the individual gaseous pollutants (CO, NO₂, O_x, and SO₂), as well as two-pollutant models for PM_2·5 with these gaseous pollutants. Subgroup analyses were done by sex and age.

FINDINGS

Over the 2 years, 249 372 OHCAs were identified, with 149 838 (60·1%) presumed of cardiac origin. The median daily PM_2·5 was 11·98 μg/m³ (IQR 8·13-17·44). Each 10 μg/m³ increase in PM_2·5 was associated with increased risk of all-cause OHCA on the same day (odds ratio [OR] 1·016, 95% CI 1·009-1·023) and at lags of up to 3 days, ranging from OR 1·015 (1·008-1·022) at lag 1 to 1·033 (1·023-1·043) at lag 0-3. Results for cardiac OHCA were similar (ORs ranging from 1·016 [1·007-1·025] at lags 1 and 2 to 1·034 [1·021-1·047] at lag 0-3). Patients older than 65 years were more susceptible to PM_2·5 exposure than younger age groups but no sex differences were identified. CO, O_x, and SO₂ were also positively associated with OHCA while NO₂ was not. However, in two-pollutant models of PM_2·5 and gaseous pollutants, only PM_2·5 (positive association) and NO₂ (negative association) were independently associated with increased risk of OHCA.

INTERPRETATION

Short-term exposure to PM_2·5 was associated with an increased risk of OHCA even at relatively low concentrations. Regulatory standards and targets need to incorporate the potential health gains from continual air quality improvement even in locations already meeting WHO standards.

FUNDING

None.

Ambient Air Pollution and Mortality After Cardiac Transplantation

BACKGROUND

Heart transplant recipients are at high risk for mortality, with traditional risk scores performing modestly in predicting post-transplant survival, underscoring the importance of as yet unidentified factors in determining prognosis. In this analysis, the association between PM_2.5 exposure levels and survival after heart transplantation were investigated.

OBJECTIVES

This study sought to study the association between PM_2.5 exposure and mortality following heart transplantation.

METHODS

On the basis of the zip code of residence, mortality data in patients who underwent heart transplantation (2004 to 2015) in the United Network for Organ Sharing (UNOS) database were linked with validated estimates of fine particulate matter concentrations (particles with diameter <2.5 μm [PM_2.5]; 1 × 1-km grids) for each calendar year during which a UNOS cardiac transplant recipient was at risk for death. Cox proportional hazard models were used to estimate the relationship between exposure and overall mortality adjusting for recipient, donor, and neighborhood variables.

RESULTS

A total of 21,800 patients with 86,713 patient-years of follow-up was included. Mean age at transplantation was 52.6 ± 12.6 years, 75% were male, 69% were white, and 39% had ischemic etiology of heart failure. Mean annual exposure to PM_2.5 was 10.6 ± 2.3 μg/m³. At a median follow-up of 4.8 (95% confidence interval: 2.0 to 7.8) years, 5,208 patients (23.9%) had died. The estimated mortality hazard ratio, per 10 μg/m³ increment increase in annual PM_2.5 exposure was 1.43 (95% confidence interval: 1.21 to 1.49). After adjusting for 30 recipient, donor, and neighborhood variables, the estimated mortality hazard ratio per 10 μg/m³ increment in annual exposure to PM_2.5 was 1.26 (95% confidence interval: 1.11 to 1.43) relative increase in hazard of mortality. This association was consistent across subgroups.

CONCLUSIONS

This study provides evidence linking air pollution with mortality after heart transplantation. These results suggest an important influence of a key environmental factor in outcomes following heart transplantation, and supports the need for further studies in this population.

Atherosclerosis in 16th-Century Greenlandic Inuit Mummies

This case series examines 4 Greenlandic Inuit mummies from approximately the 16th century for evidence of atherosclerosis.

Short-term effects of ambient air pollution and outdoor temperature on biomarkers of myocardial damage, inflammation and oxidative stress in healthy adults

Supplemental Digital Content is available in the text.

The mechanisms whereby ambient air pollution and temperature changes promote cardiac events remain incompletely described. Seventy-three nonsmoking healthy adults (mean age 23.3, SD 5.4 years) were followed with up to four repeated visits across 15 months in Beijing in 2014–2016. Biomarkers relevant to myocardial damage (high-sensitivity cardiac troponin I [hs-cTnI]), inflammation (growth differentiation factor-15 [GDF-15]), and oxidative stress (8-hydroxy-2′-deoxyguanosine [8-OHdG]) were measured at each visit, while ambient air pollution and temperature were monitored throughout the study. Linear mixed-effects models coupled with distributed lag nonlinear models were used to assess the impacts of each exposure measure on study outcomes. During follow-up, average daily concentrations of fine particulate matter and outdoor temperature were 62.9 µg/m³ (8.1–331.0 µg/m³) and 10.1 °C (−6.5°C to 29.5°C). Serum hs-cTnI levels were detectable in 18.2% of blood samples, with 27.4% of individuals having ≥1 detectable values. Higher levels of ambient particulates and gaseous pollutants (per interquartile range) up to 14 days before clinical visits were associated with significant alterations in hs-cTnI levels of 22.9% (95% CI, 6.4, 39.4) to 154.7% (95% CI, 94.4, 215.1). These changes were accompanied by elevations of circulating GDF-15 and urinary 8-OHdG levels. Both low (5th percentile, −2.5 °C) and high (95th percentile, 24.8°C) outdoor temperatures, with breakpoint at ~13.0°C as the reference level, were also associated with elevations of hs-cTnI levels. Short-term exposure to ambient air pollution and temperature was associated with cardiac troponin, a biomarker of myocardial damage, along with increased inflammation and oxidative stress responses. These findings extend our understanding of the biological mechanisms linking pervasive environmental exposure to adverse cardiac events.