The Future of Cardiovascular Epidemiology

IL-34 promotes foam cell formation by enhancing CD36 expression through p38 MAPK pathway

Atherosclerosis is characterized as a chronic inflammatory disease and macrophage-derived foam cells play a central role during the pathologic processes. A newly discovered cytokine interleukin-34 (IL-34) is closely associated with various inflammatory and autoimmune diseases. Expression of IL-34 in obesity, inflammatory bowel disease (IBD), rheumatoid arthritis (RA), lupus nephritis and coronary artery diseases (CAD) are significantly elevated. However, the role of IL-34 in atherosclerosis remains unknown. In our present study, we found that IL-34 treatment markedly increased the uptake of oxLDL, intracellular total and esterified cholesterol content but not cholesterol efflux, subsequently promoted foam cell formation through up-regulating CD36 expression via p38 MAPK signal pathway in bone marrow derived macrophages (BMDMs). Furthermore, treatment with IL-34 significantly elevated the oxLDL-induced up-regulation of pro-inflammatory cytokines. Our results conclude that IL-34 facilitates foam cell formation by increasing CD36-mediated lipid uptake and suggest a potential new risk biomarker for atherosclerosis.

Nutriepigenetics and cardiovascular disease

PURPOSE OF REVIEW

We present a current perspective of epigenetic alterations that can lead to cardiovascular disease (CVD) and the potential of dietary factors to counteract their actions. In addition, we discuss the challenges and opportunities of dietary treatments as epigenetic modifiers for disease prevention and therapy.

RECENT FINDINGS

Recent epigenome-wide association studies along with candidate gene approaches and functional studies in cell culture and animal models have delineated mechanisms through which nutrients, food compounds and dietary patterns may affect the epigenome. Several risk factors for CVD, including adiposity, inflammation and oxidative stress, have been associated with changes in histone acetylation, lower global DNA methylation levels and shorter telomere length. A surplus of macronutrients such as in a high-fat diet or deficiencies of specific nutrients such as folate and other B-vitamins can affect the activity of DNA methyltransferases and histone-modifying enzymes, affecting foetal growth, glucose/lipid metabolism, oxidative stress, inflammation and atherosclerosis. Bioactive compounds such as polyphenols (resveratrol, curcumin) or epigallocatechin may activate deacetylases Sirtuins (SIRTs), histone deacetylases or acetyltransferases and in turn the response of inflammatory mediators. Adherence to cardioprotective dietary patterns, such as the Mediterranean diet (MedDiet), has been associated with altered methylation and expression of genes related to inflammation and immuno-competence.

SUMMARY

The mechanisms through which nutrients and dietary patterns may alter the cardiovascular epigenome remain elusive. The research challenge is to determine which of these nutriepigenetic effects are reversible, so that novel findings translate into effective dietary interventions to prevent CVD or its progression.

New perspectives: systems medicine in cardiovascular disease

Background

Cardiovascular diseases (CVD) represent one of the most important causes of morbidity and mortality worldwide. Innovative approaches to increase the understanding of the underpinnings of CVD promise to enhance CVD risk assessment and might pave the way to tailored therapies. Within the last years, systems medicine has emerged as a novel tool to study the genetic, molecular and physiological interactions.

Conclusion

In this review, we provide an overview of the current molecular-experimental, epidemiological and bioinformatical tools applied in systems medicine in the cardiovascular field. We will discuss the status and challenges in implementing interdisciplinary systems medicine approaches in CVD.

Leading causes of cardiovascular hospitalization in 8.45 million US veterans

Background

We sought to determine the leading causes of cardiovascular (CV) hospitalization, and to describe and compare national rates of CV hospitalization by age, gender, race, ethnicity, region, and year, among U.S. veterans.

Methods

We evaluated the electronic health records of all veterans aged ≥18 years who had accessed any healthcare services at either a VA healthcare facility or a non-VA healthcare facility that was reimbursed by the VA, between January 1 2010 and December 31 2014. Among these 8,452,912 patients, we identified the 5 leading causes of CV hospitalization and compared rates of hospitalization by age, gender, race, ethnicity, region, year and type of VA healthcare user.

Results

The top 5 causes of CV hospitalization were: coronary atherosclerosis, heart failure, acute myocardial infarction, stroke and atrial fibrillation. Overall, 297,373 (3.5%) veterans were hospitalized for one or more of these cardiovascular conditions. The percentage of veterans hospitalized for one or more of these CV conditions decreased over time, from 1.23% in 2010 to 1.18% in 2013, followed by a slight increase to 1.20% in 2014. There was significant variation in rates of CV hospitalization by gender, race, ethnicity, geographic region, and urban vs. rural zip code. In particular, older, male, Black, non-Hispanic, urban and Continental region veterans experienced the highest rates of CV hospitalizations.

Conclusions

Among 8.5 million patients enrolled in the VA healthcare system from 2010 to 2014, there was substantial variation in rates of CV hospitalization by age, gender, race, geographical distribution, year, and use of non-VA (vs. VA only) healthcare care facilities.

Using big data to improve cardiovascular care and outcomes in China: a protocol for the CHinese Electronic health Records Research in Yinzhou (CHERRY) Study

INTRODUCTION

Data based on electronic health records (EHRs) are rich with individual-level longitudinal measurement information and are becoming an increasingly common data source for clinical risk prediction worldwide. However, few EHR-based cohort studies are available in China. Harnessing EHRs for research requires a full understanding of data linkages, management, and data quality in large data sets, which presents unique analytical opportunities and challenges. The purpose of this study is to provide a framework to establish a uniquely integrated EHR database in China for scientific research.

METHODS AND ANALYSIS

The CHinese Electronic health Records Research in Yinzhou (CHERRY) Study will extract individual participant data within the regional health information system of an eastern coastal area of China to establish a longitudinal population-based ambispective cohort study for cardiovascular care and outcomes research. A total of 1 053 565 Chinese adults aged over 18 years were registered in the health information system in 2009, and there were 23 394 deaths from 1 January 2009 to 31 December 2015. The study will include information from multiple epidemiological surveys; EHRs for chronic disease management; and health administrative, clinical, laboratory, drug and electronic medical record (EMR) databases. Follow-up of fatal and non-fatal clinical events is achieved through records linkage to the regional system of disease surveillance, chronic disease management and EMRs (based on diagnostic codes from the International Classification of Diseases, tenth revision). The CHERRY Study will provide a unique platform and serve as a valuable big data resource for cardiovascular risk prediction and population management, for primary and secondary prevention of cardiovascular events in China.

ETHICS AND DISSEMINATION

The CHERRY Study was approved by the Peking University Institutional Review Board (IRB00001052-16011) in April 2016. Results of the study will be disseminated through published journal articles, conferences and seminar presentations, and on the study website (http://www.cherry-study.org).

From Diabetes Care to Diabetes Cure-The Integration of Systems Biology, eHealth, and Behavioral Change

From a biological view, most of the processes involved in insulin resistance, which drives the pathobiology of type 2 diabetes, are reversible. This theoretically makes the disease reversible and curable by changing dietary habits and physical activity, particularly when adopted early in the disease process. Yet, this is not fully implemented and exploited in health care due to numerous obstacles. This article reviews the state of the art in all areas involved in a diabetes cure-focused therapy and discusses the scientific and technological advancements that need to be integrated into a systems approach sustainable lifestyle-based healthcare system and economy. The implementation of lifestyle as cure necessitates personalized and sustained lifestyle adaptations, which can only be established by a systems approach, including all relevant aspects (personalized diagnosis and diet, physical activity and stress management, self-empowerment, motivation, participation and health literacy, all facilitated by blended care and ehealth). Introduction of such a systems approach in type 2 diabetes therapy not only requires a concerted action of many stakeholders but also a change in healthcare economy, with new winners and losers. A "call for action" is put forward to actually initiate this transition. The solution provided for type 2 diabetes is translatable to other lifestyle-related disorders.

Validity of Cardiovascular Data From Electronic Sources: The Multi-Ethnic Study of Atherosclerosis and HealthLNK

BACKGROUND

Understanding the validity of data from electronic data research networks is critical to national research initiatives and learning healthcare systems for cardiovascular care. Our goal was to evaluate the degree of agreement of electronic data research networks in comparison with data collected by standardized research approaches in a cohort study.

METHODS

We linked individual-level data from MESA (Multi-Ethnic Study of Atherosclerosis), a community-based cohort, with HealthLNK, a 2006 to 2012 database of electronic health records from 6 Chicago health systems. To evaluate the correlation and agreement of blood pressure in HealthLNK in comparison with in-person MESA examinations, and body mass index in HealthLNK in comparison with MESA, we used Pearson correlation coefficients and Bland-Altman plots. Using diagnoses in MESA as the criterion standard, we calculated the performance of HealthLNK for hypertension, obesity, and diabetes mellitus diagnosis by using International Classification of Diseases, Ninth Revision codes and clinical data. We also identified potential myocardial infarctions, strokes, and heart failure events in HealthLNK and compared them with adjudicated events in MESA.

RESULTS

Of the 1164 MESA participants enrolled at the Chicago Field Center, 802 (68.9%) participants had data in HealthLNK. The correlation was low for systolic blood pressure (0.39; P<0.0001). In comparison with MESA, HealthLNK overestimated systolic blood pressure by 6.5 mm Hg (95% confidence interval, 4.2-7.8). There was a high correlation between body mass index in MESA and HealthLNK (0.94; P<0.0001). HealthLNK underestimated body mass index by 0.3 kg/m² (95% confidence interval, -0.4 to -0.1). With the use of International Classification of Diseases, Ninth Revision codes and clinical data, the sensitivity and specificity of HealthLNK queries for hypertension were 82.4% and 59.4%, for obesity were 73.0% and 89.8%, and for diabetes mellitus were 79.8% and 93.3%. In comparison with adjudicated cardiovascular events in MESA, the concordance rates for myocardial infarction, stroke, and heart failure were, respectively, 41.7% (5/12), 61.5% (8/13), and 62.5% (10/16).

CONCLUSIONS

These findings illustrate the limitations and strengths of electronic data repositories in comparison with information collected by traditional standardized epidemiological approaches for the ascertainment of cardiovascular risk factors and events.

Basic Concepts in Molecular Biology Related to Genetics and Epigenetics

The observation that "one size does not fit all" for the prevention and treatment of cardiovascular disease, among other diseases, has driven the concept of precision medicine. The goal of precision medicine is to provide the best-targeted interventions tailored to an individual's genome. The human genome is composed of billions of sequence arrangements containing a code that controls how genes are expressed. This code depends on other nonstatic regulators that surround the DNA and constitute the epigenome. Moreover, environmental factors also play an important role in this complex regulation. This review provides a general perspective on the basic concepts of molecular biology related to genetics and epigenetics and a glossary of key terms. Several examples are given of polymorphisms and genetic risk scores related to cardiovascular risk. Likewise, an overview is presented of the main epigenetic regulators, including DNA methylation, methylcytosine-phosphate-guanine-binding proteins, histone modifications, other histone regulations, micro-RNA effects, and additional emerging regulators. One of the greatest challenges is to understand how environmental factors (diet, physical activity, smoking, etc.) could alter the epigenome, resulting in healthy or unhealthy cardiovascular phenotypes. We discuss some gene-environment interactions and provide a methodological overview.

Clustering of cardiovascular risk factors and carotid intima-media thickness: The USE-IMT study

BACKGROUND

The relation of a single risk factor with atherosclerosis is established. Clinically we know of risk factor clustering within individuals. Yet, studies into the magnitude of the relation of risk factor clusters with atherosclerosis are limited. Here, we assessed that relation.

METHODS

Individual participant data from 14 cohorts, involving 59,025 individuals were used in this cross-sectional analysis. We made 15 clusters of four risk factors (current smoking, overweight, elevated blood pressure, elevated total cholesterol). Multilevel age and sex adjusted linear regression models were applied to estimate mean differences in common carotid intima-media thickness (CIMT) between clusters using those without any of the four risk factors as reference group.

RESULTS

Compared to the reference, those with 1, 2, 3 or 4 risk factors had a significantly higher common CIMT: mean difference of 0.026 mm, 0.052 mm, 0.074 mm and 0.114 mm, respectively. These findings were the same in men and in women, and across ethnic groups. Within each risk factor cluster (1, 2, 3 risk factors), groups with elevated blood pressure had the largest CIMT and those with elevated cholesterol the lowest CIMT, a pattern similar for men and women.

CONCLUSION

Clusters of risk factors relate to increased common CIMT in a graded manner, similar in men, women and across race-ethnic groups. Some clusters seemed more atherogenic than others. Our findings support the notion that cardiovascular prevention should focus on sets of risk factors rather than individual levels alone, but may prioritize within clusters.