Genetic testing for early detection of individuals at risk of coronary heart disease and monitoring response to therapy: challenges and promises

Family History of Premature Coronary Artery Disease (P-CAD)-A Non-Modifiable Risk Factor? Dietary Patterns of Young Healthy Offspring of P-CAD Patients: A Case-Control Study (MAGNETIC Project)

Dietary habits of healthy offspring with a positive family history of premature coronary artery disease (P-CAD) have not been studied so far. The aim of this study was twofold: (1) to identify dietary patterns in a sample of young healthy adults with (cases) and without (controls) family history of P-CAD, and (2) to study the association between dietary patterns and family history of P-CAD. The data came from the MAGNETIC case-control study. The participants were healthy adults aged 18⁻35 years old, with (n = 351) and without a family history of P-CAD (n = 338). Dietary data were collected with food frequency questionnaire FFQ-6. Dietary patterns (DP) were derived using principal component analysis (PCA). The associations between the adherence to DPs and family history of P-CAD were investigated using logistic regression. Two models were created: crude and adjusted for age, sex, smoking status, place of residence, financial situation, education, and physical activity at leisure time. Three DPs were identified: 'prudent', 'westernized traditional' and 'dairy, breakfast cereals, and treats'. In both crude and adjusted models, subjects with family history of P-CAD showed higher adherence by 31% and 25% to 'westernized traditional' DP (odds ratio (OR) 1.31, 95% confidence interval (95% CI): 1.12⁻1.53; p < 0.005; per 1 unit of standard deviation (SD) of DP score and adjOR 1.25, 95% CI: 1.06⁻1.48; p = 0.007; per 1 unit of SD of DP score, respectively). Young healthy adults with family history of P-CAD present unfavorable dietary patterns and are potentially a target group for CAD primary prevention programs.

Application of Single-Nucleotide Polymorphism-Related Risk Estimates in Identification of Increased Genetic Susceptibility to Cardiovascular Diseases: A Literature Review

Background

Although largely preventable, cardiovascular diseases (CVDs) are the biggest cause of death worldwide. Common complex cardiovascular disorders (e.g., coronary heart disease, hypertonia, or thrombophilia) result from a combination of genetic alterations and environmental factors. Recent advances in the genomics of CVDs have fostered huge expectations about future use of susceptibility variants for prevention, diagnosis, and treatment. Our aim was to summarize the latest developments in the field from a public health perspective focusing on the applicability of data on single-nucleotide polymorphisms (SNPs), through a systematic review of studies from the last decade on genetic risk estimating for common CVDs.

Methods

Several keywords were used for searching the PubMed, Embase, CINAHL, and Web of Science databases. Recent advances were summarized and structured according to the main public health domains (prevention, early detection, and treatment) using a framework suggested recently for translational research. This framework includes four recommended phases: “T1. From gene discovery to candidate health applications; T2. From health application to evidence-based practice guidelines; T3. From evidence-based practice guidelines to health practice; and T4. From practice to population health impacts.”

Results

The majority of translation research belongs to the T1 phase “translation of basic genetic/genomic research into health application”; there are only a few population-based impacts estimated. The studies suggest that an SNP is a poor estimator of individual risk, whereas an individual’s genetic profile combined with non-genetic risk factors may better predict CVD risk among certain patient subgroups. Further research is needed to validate whether these genomic profiles can prospectively identify individuals at risk to develop CVDs. Several research gaps were identified: little information is available on studies suggesting “Health application to evidence-based practice guidelines”; no study is available on “Guidelines to health practice.” It was not possible to identify studies that incorporate environmental or lifestyle factors in the risk estimation.

Conclusion

Currently, identifying populations having a larger risk of developing common CVDs may result in personalized prevention programs by reducing people’s risk of onset or disease progression. However, limited evidence is available on the application of genomic results in health and public health practice.

The Yin–Yang Dynamics of DNA Methylation Is the Key Regulator for Smooth Muscle Cell Phenotype Switch and Vascular Remodeling

Objective—

DNA methylation plays an important role in chronic diseases such as atherosclerosis, yet the mechanisms are poorly understood. The objective of our study is to indicate the regulatory mechanisms of DNA methylation in vascular smooth muscle cells (VSMCs) and its roles in atherosclerosis.

Approach and Results—

In ApoE −/− mice fed a Western diet, DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine, significantly attenuated atherosclerotic lesions (20.1±2.2% versus 30.8±7.5%; P =0.016) and suppressed DNA methyltransferase activity and concomitantly decreased global 5-methylcytosine content in atherosclerotic lesions of ApoE −/− mice. Using a carotid ligation model, we found that 5-aza-2′-deoxycytidine also dramatically inhibited neointimal formation (intimal area: 2.25±0.14×10 4 versus 4.07±0.22×10 4 μm 2 ; P <0.01). Abnormal methylation status at the promoter of ten–eleven translocation 2, one of the key demethylation enzymes in mammals, was ameliorated after 5-aza-2′-deoxycytidine treatment, which in turn caused an increase in global DNA hydroxymethylation and 5-hydroxymethylcytosine enrichment at the promoter of Myocardin. In vitro, 5-aza-2′-deoxycytidine treatment or DNA methyltransferase 1 knockdown decreased global 5-methylcytosine content and restored Myocardin expression in VSMCs induced by platelet-derived growth factor, thus preventing excessive VSMCs dedifferentiation, proliferation, and migration. Furthermore, DNA methyltransferase 1 binds to ten–eleven translocation 2 promoter and is required for ten–eleven translocation 2 methylation in VSMCs.

Conclusions—

The inhibitory effects of DNA demethylation on global 5-methylcytosine content and ten–eleven translocation 2 hypermethylation in atherosclerotic aorta can recover 5-hydroxymethylcytosine enrichment at the Myocardin promoter and prevent VSMC dedifferentiation and vascular remodeling.

Eight-year outcomes of a program for early prevention of cardiovascular events: a growth-curve analysis

BACKGROUND

Early identification of cardiovascular diseases allows us to prevent the progression of these diseases. The Bale/Doneen Method, a prevention and treatment program for heart attacks and ischemic strokes, has been adopted nationally in primary care and specialty clinics.

OBJECTIVES

The main purpose of this study was to evaluate the effect of the Bale/Doneen Method on lipoproteins and carotid intima-media thickness (IMT) for cardiovascular disease prevention and reduction. A secondary purpose was to illustrate the use of latent growth-curve analysis in studying trajectories of clinical outcomes and biomarkers in individual patients over time.

METHOD

This retrospective analysis is based on 576 patients at a nurse-managed ambulatory clinic who received the heart attack prevention and treatment program from 2000 to 2008. All patients were white; 61% were men; mean age was 55.5 years. Outcome measures include hemoglobin A1c, fasting blood sugar, plaque burden score (PBS), high-density lipoprotein, low-density lipoprotein (LDL), mean carotid artery IMT, and lipoprotein-associated phospholipase A2 test results. Latent growth-curve analysis was used in modeling changes in these outcome measures.

RESULTS

On average, mean IMT score decreased by 0.01 per year (P < .001), PBS decreased by 0.17 per year (P < .001), LDL decreased by 5.19 per year (P < .001), and lipoprotein-associated phospholipase A2 decreased by 3.6 per year (P < .05). Hemoglobin A1c increased by 0.04 per year (P < .001). Significant sex and age differences in the initial level and/or rate of change of mean IMT, PBS, fasting blood sugar, high-density lipoprotein, and LDL scores were found.

DISCUSSION

The current findings suggest that the Bale/Doneen Method is effective in generating a positive effect on the atherosclerotic disease process by achieving regression of disease in the carotid arteries.

How do we improve patient compliance and adherence to long-term statin therapy?

Statins are highly effective drugs prescribed to millions of people to lower LDL-cholesterol and decrease cardiovascular risk. The benefits of statin therapy seen in randomized clinical trials will only be replicated in real-life if patients adhere to the prescribed treatment regimen. But, about half of patients discontinue statin therapy within the first year, and adherence decreases with time. Patient, physician and healthcare system-related factors play a role in this problem. Recent studies have focused more on the patients' perspectives on non-adherence. Adverse events are cited as the most common cause of statin discontinuation; thus, the healthcare provider must be willing to ally and dialogue with patients to address concerns and assess the risks and benefits of continued statin therapy.

Association between the endothelial nitric oxide synthase gene Glu298Asp polymorphism and coronary heart disease: a meta‑analysis of 39 case‑control studies

Numerous studies have indicated that the human endothelial nitric oxide synthase (eNOS) gene Glu298Asp polymorphism is associated with coronary heart disease (CHD) susceptibility, however, their conclusions are inconsistent. The present meta‑analysis aimed to evaluate the precise result by searching the PubMed database and using 39 case‑control studies comprising 7489 cases and 7051 controls.Each study tested the association between the eNOS Glu298Asp polymorphism and CHD. A meta‑analysis was then conducted using the Comprehensive Meta Analysis 2.2 software to calculate the pooled odds ratios (ORs) of five genetic models with 95% confidence intervals (CIs). Publication bias was also explored. The meta‑analysis showed a significant association between the eNOS Glu298Asp polymorphism and CHD susceptibility for all the genetic models [Asp vs. Glu, OR 1.26, 95% CI 1.14‑1.40, P<0.001; Asp/Asp vs. Glu/Glu, OR 1.58, 95% CI 1.23‑2.02, P<0.001; Glu/Asp vs. Glu/Glu, OR 1.12, 95% CI 1.03‑1.22, P=0.001; (Glu/Asp+Asp/Asp) vs. Glu/Glu, OR 1.17, 95% CI 1.07‑1.27, P<0.001; Asp/Asp vs. (Glu/Glu+Glu/Asp), OR 1.59, 95% CI 1.25‑2.03, P<0.001]. Subgroup and sensitivity analyses indicated that the result was robust. A weak publication bias was detected. The results indicated that the eNOS Glu298Asp polymorphism is a risk factor for developing CHD, particularly in the Asian population.