Alcohol intake modulates the effect of a polymorphism of the cholesteryl ester transfer protein gene on plasma high density lipoprotein and the risk of myocardial infarction

A burden of proof study on alcohol consumption and ischemic heart disease

Cohort and case-control data have suggested an association between low to moderate alcohol consumption and decreased risk of ischemic heart disease (IHD), yet results from Mendelian randomization (MR) studies designed to reduce bias have shown either no or a harmful association. Here we conducted an updated systematic review and re-evaluated existing cohort, case-control, and MR data using the burden of proof meta-analytical framework. Cohort and case-control data show low to moderate alcohol consumption is associated with decreased IHD risk - specifically, intake is inversely related to IHD and myocardial infarction morbidity in both sexes and IHD mortality in males - while pooled MR data show no association, confirming that self-reported versus genetically predicted alcohol use data yield conflicting findings about the alcohol-IHD relationship. Our results highlight the need to advance MR methodologies and emulate randomized trials using large observational databases to obtain more definitive answers to this critical public health question.

An approach to identify gene-environment interactions and reveal new biological insight in complex traits

There is a long-standing debate about the magnitude of the contribution of gene-environment interactions to phenotypic variations of complex traits owing to the low statistical power and few reported interactions to date. To address this issue, the Gene-Lifestyle Interactions Working Group within the Cohorts for Heart and Aging Research in Genetic Epidemiology Consortium has been spearheading efforts to investigate G × E in large and diverse samples through meta-analysis. Here, we present a powerful new approach to screen for interactions across the genome, an approach that shares substantial similarity to the Mendelian randomization framework. We identify and confirm 5 loci (6 independent signals) interacted with either cigarette smoking or alcohol consumption for serum lipids, and empirically demonstrate that interaction and mediation are the major contributors to genetic effect size heterogeneity across populations. The estimated lower bound of the interaction and environmentally mediated heritability is significant (P < 0.02) for low-density lipoprotein cholesterol and triglycerides in Cross-Population data. Our study improves the understanding of the genetic architecture and environmental contributions to complex traits.

A new Approach to Identify Gene-Environment Interactions and Reveal New Biological Insight in Complex traits

There is a long-standing debate about the magnitude of the contribution of gene-environment interactions to phenotypic variations of complex traits owing to the low statistical power and few reported interactions to date. To address this issue, the CHARGE Gene-Lifestyle Interactions Working Group has been spearheading efforts to investigate G × E in large and diverse samples through meta-analysis. Here, we present a powerful new approach to screen for interactions across the genome, an approach that shares substantial similarity to the Mendelian randomization framework. We identified and confirmed 5 loci (6 independent signals) interacting with either cigarette smoking or alcohol consumption for serum lipids, and empirically demonstrated that interaction and mediation are the major contributors to genetic effect size heterogeneity across populations. The estimated lower bound of the interaction and environmentally mediated contribution ranges from 1.76% to 14.05% of SNP heritability of serum lipids in Cross-Population data. Our study improves the understanding of the genetic architecture and environmental contributions to complex traits.

The effect of the association between CETP variant type and alcohol consumption on cholesterol level differs according to the ALDH2 variant type

Alcohol consumption is associated with a high increased lipid profile and this association may depend on genetic risk factors. In this study, we aimed to assess the effects of genetic variation associated with alcohol consumption on lipid profiles using data from two Korean population studies. We performed a genotype association study using the HEXA (n = 51,349) and KNHANES (n = 9158) data. Genotype analyses of the two sets of Korean population data showed associations of increased total cholesterol and high-density lipoprotein (HDL)-cholesterol with CETP rs708272. The HEXA and KNHANES populations revealed differences in HDL cholesterol according to the presence of CETP rs708272, independent of ALDH2 rs671 and alcohol consumption. In contrast, total cholesterol levels were associated with alcohol consumption and ALDH2 rs671 in men with CETP rs708272 (CT and TT genotypes). Furthermore, in drinkers with ALDH2 rs671 (GA and AA genotypes), higher total cholesterol was associated with the CETP rs708272 TT minor homozygous genotype based on both HEXA and KNHANES data. Our findings demonstrated that alcohol consumption and genetic variation in either CETP or ALDH2 may be associated with cholesterol levels. We hope these findings will provide a better understanding of the relationship between alcohol consumption and cholesterol according to each individual’s genetic background.

Gene-diet interactions and cardiovascular diseases: a systematic review of observational and clinical trials

BACKGROUND

Both genetic background and diet are important determinants of cardiovascular diseases (CVD). Understanding gene-diet interactions could help improve CVD prevention and prognosis. We aimed to summarise the evidence on gene-diet interactions and CVD outcomes systematically.

METHODS

We searched MEDLINE^® via Ovid, Embase, PubMed^®, and The Cochrane Library for relevant studies published until June 6th 2022. We considered for inclusion cross-sectional, case-control, prospective cohort, nested case-control, and case-cohort studies as well as randomised controlled trials that evaluated the interaction between genetic variants and/or genetic risk scores and food or diet intake on the risk of related outcomes, including myocardial infarction, coronary heart disease (CHD), stroke and CVD as a composite outcome. The PROSPERO protocol registration code is CRD42019147031.

RESULTS AND DISCUSSION

We included 59 articles based on data from 29 studies; six articles involved multiple studies, and seven did not report details of their source population. The median sample size of the articles was 2562 participants. Of the 59 articles, 21 (35.6%) were qualified as high quality, while the rest were intermediate or poor. Eleven (18.6%) articles adjusted for multiple comparisons, four (7.0%) attempted to replicate the findings, 18 (30.5%) were based on Han-Chinese ethnicity, and 29 (49.2%) did not present Minor Allele Frequency. Fifty different dietary exposures and 52 different genetic factors were investigated, with alcohol intake and ADH1C variants being the most examined. Of 266 investigated diet-gene interaction tests, 50 (18.8%) were statistically significant, including CETP-TaqIB and ADH1C variants, which interacted with alcohol intake on CHD risk. However, interactions effects were significant only in some articles and did not agree on the direction of effects. Moreover, most of the studies that reported significant interactions lacked replication. Overall, the evidence on gene-diet interactions on CVD is limited, and lack correction for multiple testing, replication and sample size consideration.

A Nutrigenetic Update on CETP Gene–Diet Interactions on Lipid-Related Outcomes

Purpose of Review

An abnormal lipid profile is considered a main risk factor for cardiovascular diseases and evidence suggests that single nucleotide polymorphisms (SNPs) in the cholesteryl ester transfer protein (CETP) gene contribute to variations in lipid levels in response to dietary intake. The objective of this review was to identify and discuss nutrigenetic studies assessing the interactions between CETP SNPs and dietary factors on blood lipids.

Recent Findings

Relevant articles were obtained through a literature search of PubMed and Google Scholar through to July 2021. An article was included if it examined an interaction between CETP SNPs and dietary factors on blood lipids. From 49 eligible nutrigenetic studies, 27 studies reported significant interactions between 8 CETP SNPs and 17 dietary factors on blood lipids in 18 ethnicities. The discrepancies in the study findings could be attributed to genetic heterogeneity, and differences in sample size, study design, lifestyle and measurement of dietary intake. The most extensively studied ethnicities were those of Caucasian populations and majority of the studies reported an interaction with dietary fat intake. The rs708272 (TaqIB) was the most widely studied CETP SNP, where ‘B1’ allele was associated with higher CETP activity, resulting in lower high-density lipoprotein cholesterol and higher serum triglycerides under the influence of high dietary fat intake.

Summary

Overall, the findings suggest that CETP SNPs might alter blood lipid profiles by modifying responses to diet, but further large studies in multiple ethnic groups are warranted to identify individuals at risk of adverse lipid response to diet.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11883-022-00987-y.

Quantile-Dependent Expressivity and Gene-Lifestyle Interactions Involving High-Density Lipoprotein Cholesterol

BACKGROUND

The phenotypic expression of a high-density lipoprotein (HDL) genetic risk score has been shown to depend upon whether the phenotype (HDL-cholesterol) is high or low relative to its distribution in the population (quantile-dependent expressivity). This may be due to the effects of genetic mutations on HDL-metabolism being concentration dependent.

METHOD

The purpose of this article is to assess whether some previously reported HDL gene-lifestyle interactions could potentially be attributable to quantile-dependent expressivity.

SUMMARY

Seventy-three published examples of HDL gene-lifestyle interactions were interpreted from the perspective of quantile-dependent expressivity. These included interactive effects of diet, alcohol, physical activity, adiposity, and smoking with genetic variants associated with the ABCA1, ADH3, ANGPTL4, APOA1, APOA4, APOA5, APOC3, APOE, CETP, CLASP1, CYP7A1, GALNT2, LDLR, LHX1, LIPC, LIPG, LPL, MVK-MMAB, PLTP, PON1, PPARα, SIRT1, SNTA1,and UCP1genes. The selected examples showed larger genetic effect sizes for lifestyle conditions associated with higher vis-à-vis lower average HDL-cholesterol concentrations. This suggests these reported interactions could be the result of selecting subjects for conditions that differentiate high from low HDL-cholesterol (e.g., lean vs. overweight, active vs. sedentary, high-fat vs. high-carbohydrate diets, alcohol drinkers vs. abstainers, nonsmokers vs. smokers) producing larger versus smaller genetic effect sizes. Key Message: Quantile-dependent expressivity provides a potential explanation for some reported gene-lifestyle interactions for HDL-cholesterol. Although overall genetic heritability appears to be quantile specific, this may vary by genetic variant and environmental exposure.

Association of a cholesteryl ester transfer protein variant (rs1800777) with fat mass, HDL cholesterol levels, and metabolic syndrome

BACKGROUND

There is little evidence of the association between CETP SNPs and obesity and/or related metabolic parameters.

OBJECTIVE

To analyze the association of the polymorphism rs1800777 of the CETP gene with anthropometric parameters, lipid profile, metabolic syndrome and its components, and adipokine levels in obese subjects without type 2 diabetes mellitus or hypertension.

DESIGN

A population of 1005 obese subjects was analyzed. Electrical bioimpedance was performed, and blood pressure, presence of metabolic syndrome, dietary intake, physical activity, and biochemical tests were recorded.

RESULTS

Nine hundred and sixty eight patients (96.3%) had the GG genotype, 37 patients the GA genotype (3.7%) (no AA genotype was detected). Fat mass (delta: 4.4±1.1kg; p=0.04), waist circumference (delta: 5.6±2.1cm; p=0.02), and waist to hip ratio (delta: 0.04±0.01cm; p=0.01) were higher in A allele carriers than in non-A allele carriers. HDL cholesterol levels were lower in A allele carriers than in non-A allele carriers (delta: 4.2±1.0mg/dL; p=0.04). In the logistic regression analysis, the GA genotype was associated to an increased risk of central obesity (OR 7.55, 95% CI 1.10-55.70, p=0.02) and low HDL cholesterol levels (OR 2.46, 95% CI 1.23-4.91, p=0.014).

CONCLUSION

The CETP variant at position +82 is associated to lower HDL cholesterol levels, increased fat mass, and central obesity in obese subjects. These results may suggest a potential role of this variant gene in pathophysiology of adipose tissue.

Utilizing nutritional genomics to tailor diets for the prevention of cardiovascular disease: a guide for upcoming studies and implementations

INTRODUCTION

Personalized diets based on an individual's genome to optimize the success of dietary intervention and reduce genetic cardiovascular disease (CVD) risk, is one of the challenges most frequently discussed in the scientific community. Areas covered: The authors gathered literature-based evidence on nutritional genomics and CVD phenotypes, our own results and research experience to provide a critical overview of the current situation of using nutritional genomics to tailor diets for CVD prevention and to propose guidelines for future studies and implementations. Expert commentary: Hundreds of studies on gene-diet interactions determining CVD intermediate (plasma lipids, hypertension, etc.) and final phenotypes (stroke, etc.) have furnished top-level scientific evidence for claiming that the genetic effect in cardiovascular risk is not deterministic, but can be modified by diet. However, despite the many results obtained, there are still gaps in practically applying a personalized diet design to specific genotypes. Hence, a better systemization and methodological improvement of new studies is required to obtain top-level evidence that will allow their application in the future precision nutrition/medicine. The authors propose several recommendations for tackling new approaches and applications.

Myocardial infarction in the Wisconsin Longitudinal Study: the interaction among environmental, health, social, behavioural and genetic factors

OBJECTIVES

This study examined how environmental, health, social, behavioural and genetic factors interact to contribute to myocardial infarction (MI) risk.

DESIGN

Survey data collected by Wisconsin Longitudinal Study (WLS), USA, from 1957 to 2011, including 235 environmental, health, social and behavioural factors, and 77 single- nucleotide polymorphisms were analysed for association with MI. To identify associations with MI we utilized recursive partitioning and random forest prior to logistic regression and chi-squared analyses.

PARTICIPANTS

6198 WLS participants (2938 men; 3260 women) who (1) had a MI before 72 years and (2) had a MI between 65 and 72 years.

RESULTS

In men, stroke (LR OR: 5.01, 95% CI 3.36 to 7.48), high cholesterol (3.29, 2.59 to 4.18), diabetes (3.24, 2.53 to 4.15) and high blood pressure (2.39, 1.92 to 2.96) were significantly associated with MI up to 72 years of age. For those with high cholesterol, the interaction of smoking and lower alcohol consumption increased prevalence from 23% to 41%, with exposure to dangerous working conditions, a factor not previously linked with MI, further increasing prevalence to 50%. Conversely, MI was reported in <2.5% of men with normal cholesterol and no history of diabetes or depression. Only stroke (4.08, 2.17 to 7.65) and diabetes (2.71, 1.81 to 4.04) by 65 remained significantly associated with MI for men after age 65. For women, diabetes (5.62, 4.08 to 7.75), high blood pressure (3.21, 2.34 to 4.39), high cholesterol (2.03, 1.38 to 3.00) and dissatisfaction with their financial situation (4.00, 1.94 to 8.27) were significantly associated with MI up to 72 years of age. Conversely, often engaging in physical activity alone (0.53, 0.32 to 0.89) or with others (0.34, 0.21 to 0.57) was associated with the largest reduction in odds of MI. Being non-diabetic with normal blood pressure and engaging in physical activity often lowered prevalence of MI to 0.2%. Only diabetes by 65 (4.25, 2.50 to 7.24) and being exposed to dangerous work conditions at 54 (2.24, 1.36 to 3.69) remained significantly associated with MI for women after age 65, while still menstruating at 54 (0.46, 0.23 to 0.91) was associated with reduced odds of MI.

CONCLUSIONS

Together these results indicate important differences in factors associated with MI between the sexes, that combinations of factors greatly influence the likelihood of MI, that MI-associated factors change and associations weaken after 65 years of age in both sexes, and that the limited genotypes assessed were secondary to environmental, health, social and behavioral factors.

Additive Antiatherogenic Effects of CETP rs708272 on Serum LDL Subfraction Levels in Patients with CHD Under Statin Therapy

Recently, subfraction analysis of serum low density lipoprotein (LDL) is considered to be a better predictor of the risk of coronary heart disease (CHD) compared to the other lipid parameters. The aim of this study was to examine the effects of the HDL-associated Taq1B (rs708272) SNP of cholesterol ester transfer protein (CETP) gene on serum LDL subfractions in patients with CHD. Serum lipid levels were measured enzymatically and LDL subfraction analysis was carried out by the Lipoprint System (Quantimetrix, CA, USA). The CETP rs708272 SNP was studied in 66 healthy controls and 79 patients with CHD receiving statin therapy by the PCR-RFLP technique. The CHD patients had elevated antiatherogenic LDL-1 subfraction (p = 0.042), decreased atherogenic IDL-C subfraction (p = 0.023), and total IDL (p = 0.030) levels compared to the healthy controls. The CETP rs708272 Taq1B minor B2 allele was associated with increased levels of antiatherogenic LDL-1 (B2: 0.40 ± 0.20 vs. B1B1: 0.25 ± 0.08, p = 0.004) and large-LDL (LDL 1-2) subfractions in the CHD group (B2 allele: 0.68 ± 0.41 vs. B1B1: 0.42 ± 0.20; p < 0.05), while it was associated with reduced levels of the large-LDL subfraction in healthy subjects (B2 allele: 0.29 ± 0.14 vs. B1B1: 0.54 ± 0.24; p = 0.017). However, there was no statistically significant association between the CETP rs708272 SNP and small dense LDL subfraction (LDL 3-7) and lipoprotein levels (p > 0.05). Our findings have indicated that the CETP rs708272 SNP together with statin therapy may show a favorable effect on antiatherogenic LDL-1 and large-LDL subfractions in CHD patients with an atherogenic effect on large-LDL subfraction in healthy subjects. Based on these results, it can be concluded that the effects of the CETP variation on LDL subfraction could change in cardiometabolic events such as CHD and statin therapy.

Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

BACKGROUND

Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism (rs708272), the risk of developing composite ischemic cardiovascular disease (CVD) and the concentration of high-density lipoprotein cholesterol (HDL-C), but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors.

METHODS

We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0.

RESULTS

Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09-1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. RESULTS suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36-0.65, p < 0.001.

CONCLUSIONS

The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians.

Effects of chronic alcohol consumption on lipid levels, inflammatory and haemostatic factors in the general population: the ‘ATTICA’ Study

BACKGROUND

Epidemiological studies suggest an unclear effect of alcohol consumption on cardiovascular risk. This ambiguity is likely related to the quantity of alcohol consumed in populations studied. The aim of this work was to evaluate the association between chronic alcohol consumption and several clinical and biochemical parameters related to coronary risk, in cardiovascular disease free men and women.

METHODS

The 'ATTICA' study is a population-based cohort, which randomly enrolled 750 men and 883 women (18-88 years old) from area around Athens, during 2001-2002. We investigated the association between alcohol consumption and arterial blood pressure, fibrinogen levels, glucose concentration, total cholesterol, HDL and LDL, apolipoprotein A1 and B, Lp(a), uric acid, leucocyte count, triglycerides, C-reactive protein and homocysteine levels.

RESULTS

Multivariate analysis, after controlling for several potential confounders, revealed a J-shaped association between alcohol intake (none, 1-2, 3-4, 5+ wine glasses/day) and uric acid, C-reactive protein, homocysteine, fibrinogen, triglycerides, apolipoproteins A1 and B, HDL and total cholesterols, blood glucose levels, leucocyte count and arterial blood pressure levels (only in males). The most beneficial values of all these biochemical and clinical parameters were found in alcohol intake of 100-200 ml (12% alcohol), even after adjustment for various potential confounders.

CONCLUSIONS

The controversial association between alcohol intake and cardiovascular disease seems to be partially explained by the J-shaped relation of several biochemical parameters related to atherosclerosis and the amount of alcoholic beverages consumed.

Nutrigenomics, the Microbiome, and Gene-Environment Interactions: New Directions in Cardiovascular Disease Research, Prevention, and Treatment: A Scientific Statement From the American Heart Association

Cardiometabolic diseases are the leading cause of death worldwide and are strongly linked to both genetic and nutritional factors. The field of nutrigenomics encompasses multiple approaches aimed at understanding the effects of diet on health or disease development, including nutrigenetic studies investigating the relationship between genetic variants and diet in modulating cardiometabolic risk, as well as the effects of dietary components on multiple "omic" measures, including transcriptomics, metabolomics, proteomics, lipidomics, epigenetic modifications, and the microbiome. Here, we describe the current state of the field of nutrigenomics with respect to cardiometabolic disease research and outline a direction for the integration of multiple omics techniques in future nutrigenomic studies aimed at understanding mechanisms and developing new therapeutic options for cardiometabolic disease treatment and prevention.

A U-shaped relationship between alcohol consumption and cardiometabolic index in middle-aged men

BACKGROUND

Cardiometabolic index (CMI) is a new index for discriminating diabetes. The purpose of this study was to determine whether CMI is affected by habitual alcohol drinking.

METHODS

The subjects were 21572 men (35-60 years) receiving annual health checkups. They were divided by average daily ethanol consumption into non-, light (< 22 g), moderate (≥ 22 and < 44 g), heavy (≥ 44 and < 66 g) and very heavy (≥ 66 g) drinkers. Relationship between alcohol intake and CMI was investigated with adjustment for age and histories of smoking and regular exercise.

RESULTS

Log-transformed CMI was significantly lower in light, moderate and heavy drinkers than in nondrinkers and was lowest in light drinkers, while there was no significant difference in log-transformed CMI of nondrinkers and very heavy drinkers. Odds ratio vs. nondrinkers for high CMI was significantly lower than the reference level of 1.00 in light, moderate and heavy drinkers and was lowest in light drinkers but was not significantly different from the reference level in very heavy drinkers. Odds ratio of subjects with vs. those without high CMI for hyperglycemia was significantly higher than the reference level in all of the alcohol groups and was significantly lower in moderate drinkers but was not significantly different in the other drinker groups when compared with the nondrinker group.

CONCLUSION

There is a U-shaped relationship between alcohol consumption and CMI, and moderate drinking but not excessive drinking attenuates the association between CMI and hyperglycemia.

The impact of common polymorphisms in CETP and ABCA1 genes with the risk of coronary artery disease in Saudi Arabians

Background

Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Many genetic and environmental risk factors including atherogenic dyslipidemia contribute towards the development of CAD. Functionally relevant mutations in the dyslipidemia-related genes and enzymes involved in the reverse cholesterol transport system are associated with CAD and contribute to increased susceptibility of myocardial infarction (MI).

Method

Blood samples from 990 angiographically confirmed Saudi CAD patients with at least one event of myocardial infarction were collected between 2012 and 2014. A total of 618 Saudi controls with no history or family history of CAD participated in the study. Four polymorphisms, rs2230806, rs2066715 (ABCA1), rs5882, and rs708272 (CETP), were genotyped using TaqMan Assay.

Results

CETP rs5882 (OR = 1.45, P < 0.005) and ABCA1 rs2230806 (OR = 1.42, P = 0.017) polymorphisms were associated with increased risk of CAD. However, rs708272 polymorphism showed protective effect (B1 vs. B2: OR = 0.80, P = 0.003 and B2B2 vs. B1B1: OR = 0.68, P = 0.012) while the ABCA1 variant rs2066715 was not associated.

Conclusion

This study is the first to report the association of these polymorphisms with CAD in the population of the Eastern Province of Saudi Arabia. The rs5882 polymorphism (CETP) showed a significant association and therefore could be a promising marker for CAD risk estimation while the rs708272 polymorphism had a protective effect from CAD.

Interaction of cholesterol ester transfer protein polymorphisms, body mass index, and birth weight with the risk of dyslipidemia in children and adolescents: the CASPIAN-III study

OBJECTIVES

This study aims to investigate joint association between cholesterol ester transfer protein (CETP) polymorphisms and body mass index (BMI) or birth weight with the risk of dyslipidemia in Iranian children and adolescents.

MATERIALS AND METHODS

This study was conducted as a sub-study of the "school-based nationwide health survey" (CASPIAN-III). We randomly selected 750 samples from the whole blood samples. Real-time PCR and high resolution melt (HRM) analysis were performed to determine Taq1B (rs708272) and A373P (rs5880) polymorphisms.

RESULTS

Taq1B polymorphism increased HDL-C, and total cholesterol (TC) as well as decreased triglyceride and LDL-C concentrations. LDL-C and triglyceride levels were significantly higher and HDL-C and TC levels were significantly lower among those with A373P polymorphism. CT/TT genotype in Taq1B polymorphism showed a protective effect on dyslipidemia (OR= 0.12, 95% CI: 0.07-0.20). G allele of A373P polymorphism increased the risk of dyslipidemia (OR=4.10, 95% CI: 2.14, 7.83) after adjusting the confounders. We observed interactive effects of CETP gene polymorphisms and BMI or birth weight on dyslipidemia.

CONCLUSION

Findings showed Taq1B polymorphism might have a protective effect and A373P polymorphism had deleterious effect on dyslipidemia in Iranian children and adolescents. These associations interacted with BMI and birth weight.

TaqIB and severity of coronary artery disease in the Turkish population: a pilot study

The cholesteryl ester transfer protein (CETP) plays a crucial role in high-density lipoprotein (HDL) metabolism. Genetic variants that alter CETP concentration may cause significant alterations in HDL-cholesterol (HDL-C) concentration. In this case-control study, we analyzed the genotype frequencies of CETP Taq1B polymorphisms in coronary artery disease patients (CAD; n=210) and controls (n=100). We analyzed the role of the CETP Taq1B variant in severity of CAD, and its association with plasma lipids and CETP concentration. DNA was extracted from 310 patients undergoing coronary angiography. The Taq1B polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (RFLP) analysis. Lipid concentrations were measured by an auto analyzer and CETP level by a commercial enzyme-linked immunosorbent assay (ELISA) kit. In our study population, the B2 allele frequency was higher in control subjects than patients with single, double or triple vessel disease. B2B2 genotype carriers had a significantly higher high-density lipoprotein cholesterol (HDL-C) concentration than those with the B1B1 genotype in controls (51.93±9.47versus 45.34±9.93; p<0.05) and in CAD patients (45.52±10.81 versus 40.38±9.12; p<0.05). B2B2 genotype carriers had a significantly lower CETP concentration than those with the B1B1 genotype in controls (1.39±0.58 versus 1.88±0.83; p< 0.05) and in CAD patients (2.04±1.39versus 2.81±1.68; p< 0.05). Our data suggest that the B2 allele is associated with higher concentrations of HDL-C and lower concentrations of CETP, which confer a protective effect on coronary artery disease.

Circulating cholesteryl ester transfer protein and coronary heart disease: mendelian randomization meta-analysis

BACKGROUND

The cholesteryl ester transfer protein (CETP) plays a central role in reverse cholesterol transport. Currently, it remains unresolved whether circulating CETP is causally associated with coronary heart disease (CHD). We aimed to investigate this causal association using CETP gene rs708272 polymorphism as an instrument in a Mendelian randomization meta-analysis.

METHODS AND RESULTS

We searched PubMed and EMBASE before May 2014. Data and study quality were assessed in duplicate. Thirty-four articles (17 813 CHD patients and 22 203 controls) were qualified. Overall analyses revealed a significant association of rs708272-B1 allele with a reduced CHD risk compared with B2 allele under allelic (odds ratio and 95% confidence interval: 0.87 and 0.82-0.92; P<0.001), homozygous genotypic (0.74 and 0.66-0.83; P<0.001), and dominant (0.87 and 0.80-0.94; P<0.001) models. Carriers of rs708272-B1B1 genotype (weighted mean difference and 95% confidence interval: -0.21 and -0.41 to 0.00 μg/dL; P=0.052) or B1 allele (-0.15 and -0.30 to 0.00 μg/dL; P=0.056) had a marginally lower circulating CETP level compared with B2B2 genotype carriers. In Mendelian randomization analysis, there was a 25% (odds ratio and 95% confidence interval: 0.75 and 0.19-0.91) and a 17% (0.83 and 0.41-0.96) significantly reduced risk of CHD by a reduction of 0.2 μg/mL in circulating CETP for the comparison of B1B1 genotype and B1 allele with B2B2 genotype, respectively. There were low probabilities of publication bias.

CONCLUSIONS

Our findings demonstrate that the long-term genetically reduced circulating CETP might be causally associated with the low risk of CHD.

CETP genotype and changes in lipid levels in response to weight-loss diet intervention in the POUNDS LOST and DIRECT randomized trials

Little is known about whether cholesteryl ester transfer protein (CETP) genetic variation may modify the effect of weight-loss diets varying in fat content on changes in lipid levels. We analyzed the interaction between the CETP variant rs3764261 and dietary interventions on changes in lipid levels among 732 overweight/obese adults from a 2 year randomized weight-loss trial [Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST)], and replicated the findings in 171 overweight/obese adults from an independent 2 year weight-loss trial [Dietary Intervention Randomized Controlled Trial (DIRECT)]. In the POUNDS LOST, participants with the CETP rs3764261 CC genotype on the high-fat diet had larger increases in HDL cholesterol (P = 0.001) and decreases in triglycerides (P = 0.007) than those on the low-fat diet at 6 months, while no significant difference between these two diets was observed among participants carrying other genotypes. The gene-diet interactions on changes in HDL-cholesterol and tri-glyc-erides were replicated in the DIRECT (pooled P for interaction ≤ 0.01). Similar results on trajectory of changes in HDL cholesterol and triglycerides over the 2 year intervention were observed in both trials. Our study provides replicable evidence that individuals with the CETP rs3764261 CC genotype might derive greater effects on raising HDL cholesterol and lowering triglycerides by choosing a low-carbohydrate/high-fat weight-loss diet instead of a low-fat diet.

Meta-analysis of cholesteryl ester transfer protein TaqIB polymorphism and risk of myocardial infarction

A number of studies have been conducted to explore the association between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism and risk of myocardial infarction (MI); however, the results are inconsistent. Therefore, we conducted this meta-analysis to clarify the issue based on all the data available.Eligible studies were retrieved by searching PubMed, Embase, Web of Science, and Google Scholar. We calculated the crude odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) to assess the association between the TaqIB polymorphism and risk of MI.We included 13 studies involving 8733 MI cases and 8573 controls in the meta-analysis. The pooled results from all included studies showed decreased MI risk in the analysis of the B2B2 versus B1B1 (OR = 0.78, 95% CI = 0.68-0.91), dominant (OR = 0.88, 95% CI = 0.77-0.99), and recessive genetic models (OR = 0.84, 95% CI = 0.78-0.91). The frequency of the B2B2 genotype in MI patients was lower (OR = 0.87, 95% CI = 0.81-0.94). However, there was no significant association in the B1B2 versus B1B1 analysis (OR = 0.92, 95% CI = 0.81-1.05) and no significant difference for the B1B1 genotype (OR = 1.04, 95% CI = 0.98-1.11) and B1B2 genotype (OR = 1.03, 95% CI = 0.97-1.08). Cumulative analysis confirmed these results.Our results suggest that the B2B2 genotype of the CETP TaqIB polymorphism is a protective factor against the development of MI.

Aging and cardiovascular diseases: the role of gene-diet interactions

In the study of longevity, increasing importance is being placed on the concept of healthy aging rather than considering the total number of years lived. Although the concept of healthy lifespan needs to be defined better, we know that cardiovascular diseases (CVDs) are the main age-related diseases. Thus, controlling risk factors will contribute to reducing their incidence, leading to healthy lifespan. CVDs are complex diseases influenced by numerous genetic and environmental factors. Numerous gene variants that are associated with a greater or lesser risk of the different types of CVD and of intermediate phenotypes (i.e., hypercholesterolemia, hypertension, diabetes) have been successfully identified. However, despite the close link between aging and CVD, studies analyzing the genes related to human longevity have not obtained consistent results and there has been little coincidence in the genes identified in both fields. The APOE gene stands out as an exception, given that it has been identified as being relevant in CVD and longevity. This review analyzes the genomic and epigenomic factors that may contribute to this, ranging from identifying longevity genes in model organisms to the importance of gene-diet interactions (outstanding among which is the case of the TCF7L2 gene).

CETP TaqIB genotype modifies the association between alcohol and coronary heart disease: the INTERGENE case-control study

Alcohol consumption at moderate levels has been associated with decreased risk of coronary heart disease (CHD). However, the cardio-protective effect of alcohol may be restricted to subjects with a particular genotype of the cholesteryl ester transfer protein (CETP) polymorphism. There is evidence for this from one study in men, but the finding has not been confirmed since. The present study specifically re-examines the potential modification of the association between alcohol consumption and CHD by the CETP TaqIB (rs708272) polymorphism in a sample including both men and women. The INTERGENE case-control study consists of 618 patients with CHD and 2921 control subjects, of whom 19% were homozygous for the CETP TaqIB B2 allele. Alcohol consumption was categorized into sex-specific tertiles of ethanol intake, with non-drinkers constituting a separate category. Logistic regression was used to determine the association between CHD with genotype, ethanol intake, and their interaction. Participants with intermediate ethanol intake (2nd tertile) had lower risk of CHD than those with low ethanol intake (odds ratio [OR] = 0.65; 95% confidence interval [CI] 0.50-0.85). The strongest protective association was seen in the CETP TaqIB B2 homozygotes for intermediate vs. low ethanol intake (odds ratio OR = 0.21; 95% CI 0.10-0.44). The interaction between ethanol intake and genotype was statistically significant (p = 0.008), and of similar size in men and women though significant only in men (p = 0.01). The effect modification could not be explained by differences in lifestyle, socioeconomics, or alcohol-related biological variables such as HDL-cholesterol. Our study is the first to replicate previous findings of an effect modification in men. It gives only suggestive results for women, possibly due to the small number of female cases (n = 165). The prevented fraction for the favorable combination of genotype and alcohol consumption is about 6%, a value suggesting that the cardio-protective effect of moderate alcohol consumption applies only to a small segment of the general population.

Association of cholesteryl ester transfer protein (CETP) gene polymorphism, high density lipoprotein cholesterol and risk of coronary artery disease: a meta-analysis using a Mendelian randomization approach

BACKGROUND

Recent randomized controlled trials have challenged the concept that increased high density lipoprotein cholesterol (HDL-C) levels are associated with coronary artery disease (CAD) risk reduction. The causal role of HDL-C in the development of atherosclerosis remains unclear. To increase precision and to minimize residual confounding, we exploited the cholesteryl ester transfer protein (CETP)-TaqIB polymorphism as an instrument based on Mendelian randomization.

METHODS

The Mendelian randomization analysis was performed by two steps. First, we conducted a meta-analysis of 47 studies, including 23,928 cases and 27,068 controls, to quantify the relationship between the TaqIB polymorphism and the CAD risk. Next, the association between the TaqIB polymorphism and HDL-C was assessed among 5,929 Caucasians. We further employed Mendelian randomization to evaluate the causal effect of HDL-C on CAD based on the findings from the meta-analysis.

RESULTS

The overall comparison of the B2 allele with the B1 allele yielded a significant risk reduction of CAD (P < 0.0001; OR = 0.88; 95% CI: 0.84-0.92) with substantial between-study heterogeneity (I² = 55.2%; P(heterogeneity) <0.0001). The result was not materially changed after excluding the Hardy-Weinberg Equilibrium (HWE)-violation studies. Compared with B1B1 homozygotes, Caucasian carriers of the B2 allele had a 0.25 mmol/L increase in HDL-C level (95% CI: 0.20-0.31; P <0.0001; I² = 0; P(heterogeneity) =0.87). However, a 1 standard deviation (SD) elevation in HDL-C levels due to the TaqIB polymorphism, was marginal associated with CAD risk (OR =0.79; 95% CI: 0.54-1.03; P =0.08).

CONCLUSIONS

Taken together, our results lend support to the concept that increased HDL-C cannot be translated into a reduction in CAD risk.

Association of cholesteryl ester transfer protein genotypes with paraoxonase-1 activity, lipid profile and oxidative stress in type 2 diabetes mellitus: A study in San Luis, Argentina

Aims/Introduction

Diabetic dyslipidemia is common in type 2 diabetes. The TaqIB polymorphism in cholesteryl ester transfer protein (CETP; B1 and B2 alleles; rs708272) is associated with changes in enzyme activity and lipid concentrations. The aim of the present study was to assess associations of CETP genotypes with lipoprotein profile, oxidant/anti-oxidant status and the plasma activity of paraoxonase-1 (PON-1) in a population of diabetic patients living in San Luis, Argentina.

Materials and Methods

For oxidative stress status parameters, thiobarbituric acid-reactive substances (TBARS) and nitric oxide (NO) levels, and catalase and PON-1 activity were assessed in 40 patients with type 2 diabetes mellitus and 30 healthy participants. CETP polymorphism was analyzed by polymerase chain reaction-based methods.

Results

Type 2 diabetes mellitus had significantly higher concentrations of oxidative stress parameters: TBARS (P < 0.0001) and catalase activity (P < 0.0001). PON-1 activity and NO levels were significantly lower in diabetics (P = 0.0002 and P = 0.0008, respectively). The CETP genotypes distribution among study groups was not significantly different. The B2 carriers of the TaqIB CETP polymorphism are associated with higher high-density lipoprotein cholesterol levels and PON-1 activity in control and type 2 diabetes mellitus patients. Linear regression analysis showed that there was a significant and positive correlation between the changes of PON-1 activity and high-density lipoprotein cholesterol levels in non-B1B1 (B2 carriers) in controls (r = 0.83, P < 0.0001) and diabetic patients (r = 0.39, P = 0.0003).

Conclusions

The results of the current study show that type 2 diabetes mellitus is characterized by intense oxidative stress, and that the alterations observed in the lipoprotein profile and PON-1 activity might be related to the higher CETP activity in diabetic patients as a consequence of insulin resistance.

Common variants of apolipoprotein E and cholesteryl ester transport protein genes in male patients with coronary heart disease and variable body mass index

Plasma lipids are major risk factors for coronary heart disease (CHD). Cholesteryl ester transfer protein (CETP) and apolipoprotein (apo) E genes are involved in lipoprotein metabolism, thus affecting plasma lipid and lipoproteins levels. Furthermore, such polymorphisms have been associated with susceptibility to CHD and obesity. We evaluated the influence of the gene polymorphisms of CETP TaqIB (B1, B2) and I405V (V, I) and apo E (∊2,∊3,∊4) on lipid levels, according to body mass index (BMI) in Greek men with CHD. The TaqIB (B1, B2) polymorphism affected plasma low-density lipoprotein cholesterol levels in overweight men with CHD, whereas the I405V (V, I) polymorphism affected triglyceride concentrations in normal weight men. No correlation was found between BMI and apo E polymorphisms. Large prospective studies are required to investigate the relationships of CETP and apo E polymorphisms with lipids, BMI, and CHD susceptibility.

Association of CETP Taq1B and -629C > A polymorphisms with coronary artery disease and lipid levels in the multi-ethnic Singaporean population

BACKGROUND

Hyperlipidaemia is a major risk factor for coronary artery disease (CAD) and cholesteryl ester transfer protein (CETP) gene polymorphisms are known to be associated with lipid profiles.

METHODS

In this study, we investigated the association of two polymorphisms in the CETP, Taq1B (rs708272) and -629C > A (rs1800775), with CAD and lipid levels HDL-C in 662 CAD + cases and 927 controls from the Singapore population comprising Chinese, Malays and Indians.

RESULTS

TaqB2 frequency was significantly lowest in the Malays (0.43) followed by Chinese (0.47) and highest in the Indians (0.56) in the controls. The B2 allele frequency was significantly lower in the Chinese CAD + cases compared to the controls (p = 0.002). The absence of the B2 allele was associated with CAD with an OR 2.0 (95% CI 1.2 to 3.4) after adjustment for the confounding effects of age, smoking, BMI, gender, hypertension, dyslipidemia and diabetes mellitus. The B2 allele was significantly associated with higher plasma HDL-C levels in the Chinese men after adjusting for confounders. Associations with plasma apoA1 levels were significant only in the Chinese men for Taq1B and -629C > A. In addition, the Taq1B polymorphism was only associated with plasma Apo B and Lp(a) in the Malay men. Significant associations were only found in non-smoking subjects with BMI <50th percentile. In this study, the LD coefficients between the Taq1B and -629C > A polymorphisms seemed to be weak.

CONCLUSION

The absence the Taq1B2 allele was associated with CAD in the Chinese population only and the minor allele of the Taq1B polymorphism of the CETP gene was significantly associated with higher plasma HDL-C levels in Chinese men.

Four polymorphisms of cholesteryl ester transfer protein gene and coronary stenosis in a Tunisian population

AIMS

The role of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is under debate. We studied the association of four polymorphisms (Taq1B, I405V, R451Q and A373P) in the CETP gene with lipid profile and coronary artery disease.

METHODS

Four CETP polymorphisms were studied in 316 Tunisian patients undergoing coronary angiography. Patients were clinically examined and their lipid profiles were estimated. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The 451Q allele, associated with lower high-density lipoprotein-cholesterol (HDL-C) and higher total cholesterol and apolipoprotein B (ApoB) concentrations, was also significantly associated with an increased risk of significant stenosis [odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.15-2.61, P = 0.007]. The B2 allele of Taq1B polymorphism had an increase in HDL-C concentration and was associated with a decreased risk of coronary stenosis, as described earlier. It was also associated with low risk of hypoHDLaemia [OR = 0.615, 95% CI 0.377-1.002, P = 0.035]. No significant effect of different A373P and I405V alleles was found on the lipid profile and on coronary stenosis. When CETP polymorphisms were combined in haplotypes possessing R451Q, A373P, I405V, Taq1B polymorphisms, the 1112 haplotype (where 1 is the wild genotype and 2 represents carriers of the variant allele) seems to be the most protective against significant stenosis (OR = 0.71, 95% CI 0.188-0.983; P = 0.014), whereas 2111 was probably the most atherogenic, with an OR = 2.17, 95% CI 1.06-5.88; P = 0.039.

CONCLUSION

The Q allele of the R451Q polymorphism was associated with decreased HDL-C, increased ApoB concentrations and increased risk of coronary stenosis. In haplotype analysis, we found that 1112 seems to be a protective haplotype, whereas 2111 has an atherogenic effect in a coronary Tunisian population.

The I405V and Taq1B polymorphisms of the CETP gene differentially affect sub-clinical carotid atherosclerosis

Background

Cholesteryl ester transfer protein (CETP) plays a major role in lipid metabolism, but studies on the association of CETP polymorphisms with risks of cardiovascular disease are inconsistent. This study investigated whether the CETP gene I405V and Taq1B polymorphisms modified subclinical atherosclerosis in an asymptomatic Brazilian population sample.

Methods

The polymorphisms were analyzed using polymerase chain reaction in 207 adult volunteers. Serum lipid profiles, oxLDL Ab titers, C-reactive protein and tumor necrosis factor-α concentrations and CETP and phospholipid transfer protein (PLTP) activities were determined, and common carotid artery intima-media thickness (cIMT) was measured using ultrasonography.

Results

No differences in cIMT were observed between the presence or absence of the minor B2 and V alleles in either polymorphism. However, inverse correlations between mean cIMT and CETP activity in the presence of these polymorphisms were observed, and positive correlations of these polymorphisms with PLTP activity and oxLDL Ab titers were identified. Moreover, logistic multivariate analysis revealed that the presence of the B2 allele was associated with a 5.1-fold (CI 95%, OR: 1.26 – 21.06) increased risk for cIMT, which was equal and above the 66^th percentile and positively interacted with age. However, no associations with the V allele or CETP and PLTP activities were observed.

Conclusions

None of the studied parameters, including CETP activity, explained the different relationships between these polymorphisms and cIMT, suggesting that other non-determined factors were affected by the genotypes and related to carotid atherosclerotic disease.

Cholesteryl ester transfer protein TaqIB polymorphism and its association with serum lipid levels and longevity in Chinese Bama Zhuang population

BACKGROUND

TaqIB polymorphism in the cholesteryl ester transfer protein (CETP) gene has been reported to be associated with serum high-density lipoprotein cholesterol (HDL-C) levels and longevity in several populations, but controversial results also arose probably due to racial/ethnic diversity. Bama is a remote and mountainous county located in the northwest of Guangxi, People's Republic of China, which has been well known for its longevity for centuries. The current study was to investigate the possible association of CETP TaqIB polymorphism with serum lipid levels and longevity in the Bama Zhuang population.

METHODS

The CETP TaqIB genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism in 523 long-lived inhabitants (long-lived group, LG; aged 90-107 years) and 498 healthy controls without longevity family history (non-long-lived group, non-LG; aged 40-69 years) residing in Bama County.

RESULTS

The levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were higher but TG, HDL-C/LDL-C ratio and the prevalence of dyslipidemia were lower in LG than in non-LG (P < 0.001 for all). There were no differences in the allelic and genotypic frequencies between the two groups (P > 0.05). Serum HDL-C levels and HDL-C/LDL-C ratio in LG were different among the genotypes (P < 0.01 for each), the subjects with B2B2 and B1B2 genotyes had higher HDL-C levels and HDL-C/LDL-C ratio than the subjects with B1B1genotye, whereas the levels of TC and HDL-C in non-LG were different among/between the genotypes (P < 0.01 for each), the B2 allele carriers had lower TC and higher HDL-C levels than the B2 allele noncarriers. Serum TG and HDL-C levels and HDL-C/LDL-C ratio were correlated with genotypes in LG, whereas serum TC and HDL-C levels were associated with genotypes in non-LG (P < 0.05-0.001).

CONCLUSIONS

The association of CETP TaqIB polymorphism and serum lipid profiles is different between LG and non-LG in the Chinese Bama Zhuang population. CETP TaqIB polymorphism might be one of the longevity-related genetic factors in this population.

Increased body mass index modifies associations between alcohol intake and blood cholesterol profile

BACKGROUND AND OBJECTIVES

Habitual alcohol drinking influences blood cholesterol profile, and dyslipidaemia often accompanies obesity. The aim of this study was to determine whether obesity modifies relationships between alcohol intake and blood cholesterol profile.

METHODS

  Japanese men aged 35-60 years (n = 23 834) were divided into two groups by body mass index (BMI) (normal BMI: ≥ 18·5 and < 25 kg/m(2) ; high BMI: ≥ 25 kg/m(2) ) and were further divided into four subgroups by alcohol intake [non-, light (< 22 g ethanol/day), heavy (≥ 22 and < 44 g ethanol/day) and very heavy (≥ 44 g ethanol/day) drinkers]. Relationships of alcohol intake with serum LDL cholesterol, HDL cholesterol and LDL/HDL ratio were investigated.

RESULTS

Both in the subject groups with normal and high BMI, alcohol intake was associated with lower risks of high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio, and these risks tended to decrease as alcohol intake increased. The odds ratios vs. nondrinkers for high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio tended to be lower in the normal BMI group than in the high BMI group. Significant interactions between alcohol drinking and BMI for high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio were found in all of the drinker subgroups except for the interaction for high LDL cholesterol in light drinkers.

CONCLUSIONS

High BMI status is suggested to attenuate the associations of alcohol intake with lower LDL cholesterol, higher HDL cholesterol and lower LDL/HDL ratio.

Quantile-specific penetrance of genes affecting lipoproteins, adiposity and height

Quantile-dependent penetrance is proposed to occur when the phenotypic expression of a SNP depends upon the population percentile of the phenotype. To illustrate the phenomenon, quantiles of height, body mass index (BMI), and plasma lipids and lipoproteins were compared to genetic risk scores (GRS) derived from single nucleotide polymorphisms (SNP)s having established genome-wide significance: 180 SNPs for height, 32 for BMI, 37 for low-density lipoprotein (LDL)-cholesterol, 47 for high-density lipoprotein (HDL)-cholesterol, 52 for total cholesterol, and 31 for triglycerides in 1930 subjects. Both phenotypes and GRSs were adjusted for sex, age, study, and smoking status. Quantile regression showed that the slope of the genotype-phenotype relationships increased with the percentile of BMI (P = 0.002), LDL-cholesterol (P = 3×10⁻⁸), HDL-cholesterol (P = 5×10⁻⁶), total cholesterol (P = 2.5×10⁻⁶), and triglyceride distribution (P = 7.5×10⁻⁶), but not height (P = 0.09). Compared to a GRS's phenotypic effect at the 10^th population percentile, its effect at the 90^th percentile was 4.2-fold greater for BMI, 4.9-fold greater for LDL-cholesterol, 1.9-fold greater for HDL-cholesterol, 3.1-fold greater for total cholesterol, and 3.3-fold greater for triglycerides. Moreover, the effect of the rs1558902 (FTO) risk allele was 6.7-fold greater at the 90^th than the 10^th percentile of the BMI distribution, and that of the rs3764261 (CETP) risk allele was 2.4-fold greater at the 90^th than the 10^th percentile of the HDL-cholesterol distribution. Conceptually, it maybe useful to distinguish environmental effects on the phenotype that in turn alters a gene's phenotypic expression (quantile-dependent penetrance) from environmental effects affecting the gene's phenotypic expression directly (gene-environment interaction).

Moderate ethanol ingestion and cardiovascular protection: from epidemiologic associations to cellular mechanisms

While ethanol intake at high levels (3-4 or more drinks), either in acute (occasional binge drinking) or chronic (daily) settings, increases the risk for myocardial infarction and stroke, an inverse relationship between regular consumption of alcoholic beverages at light to moderate levels (1-2 drinks per day) and cardiovascular risk has been consistently noted in a large number of epidemiologic studies. Although initially attributed to polyphenolic antioxidants in red wine, subsequent work has established that the ethanol component contributes to the beneficial effects associated with moderate intake of alcoholic beverages regardless of type (red versus white wine, beer, spirits). Concerns have been raised with regard to interpretation of epidemiologic evidence for this association including heterogeneity of the reference groups examined in many studies, different lifestyles of moderate drinkers versus abstainers, and favorable risk profiles in moderate drinkers. However, better controlled epidemiologic studies and especially work conducted in animal models and cell culture systems have substantiated this association and clearly established a cause and effect relationship between alcohol consumption and reductions in tissue injury induced by ischemia/reperfusion (I/R), respectively. The aims of this review are to summarize the epidemiologic evidence supporting the effectiveness of ethanol ingestion in reducing the likelihood of adverse cardiovascular events such as myocardial infarction and ischemic stroke, even in patients with co-existing risk factors, to discuss the ideal quantities, drinking patterns, and types of alcoholic beverages that confer protective effects in the cardiovascular system, and to review the findings of recent experimental studies directed at uncovering the mechanisms that underlie the cardiovascular protective effects of antecedent ethanol ingestion. Mechanistic interrogation of the signaling pathways invoked by antecedent ethanol ingestion may point the way towards development of new therapeutic approaches that mimic the powerful protective effects of socially relevant alcohol intake to limit I/R injury, but minimize the negative psychosocial impact and pathologic outcomes that also accompany consumption of ethanol.

Alcohol intake

Alcohol consumption and its association with health or illness states are of great interest from the nutritional genomics point of view. This interest is centered not only on investigating the genetic variants that can modulate the effects of alcoholic beverages on different intermediate and final disease phenotypes (mainly cardiovascular diseases and cancer), but also on finding out how the genome influences the amount of alcohol consumed and consumption habits. This chapter reviews the latest findings on alcohol consumption trends, the methodological limitations in the analysis of alcohol consumption, and the main genes and polymorphisms related to alcohol intake, including the inconsistent results from genome-wide association studies (GWASs). It also reviews the effects of alcohol consumption on cardiovascular diseases and cancer and the studies analyzing the interactions between different genetic polymorphisms and alcohol in phenotypes related to these diseases, discussing the studies' advantages and limitations as well as future research perspectives.

The role of common variants of the cholesteryl ester transfer protein gene in left main coronary artery disease

BACKGROUND

The cholesteryl ester transfer protein (CETP) has a central role in the lipid metabolism and therefore may alter the susceptibility to atherosclerosis.

METHODS

The DNA of 471 subjects [133 subjects with angiographically documented left main coronary artery disease (LMCAD), 241 subjects with more peripheral coronary artery disease (MPCAD) and 97 subjects self reported healthy (Controls)] was analyzed for the frequency of TaqIB and I405V polymorphisms in the gene coding CETP.

RESULTS

There is no significant difference in CETP allele frequency or genotype distribution among LMCAD and MPCAD patients although there is statistical difference between LMCAD and Controls (p = 0.001). Specifically, patients with LMCAD and B1B1 genotype of TaqIB polymorphism were more frequent present compared to Controls (33.8% vs 22.9%, respectively). The frequency of B2B2 genotype was 3 times lower in the LMCAD group compared to Controls (10.5% vs 30.2%, respectively). In the LMCAD group the frequency of B1 allele compared to Controls was higher (62% vs 46%, respectively, p = 0.001). The relationship between TaqIB gene polymorphism and the LMCAD was independent of lipid profile, with the exception of apolipoprotein A.

CONCLUSIONS

These findings indicate that the TaqIB polymorphism may have potential importance in screening individuals at high risk for developing CAD. However, this polymorphism cannot distinguish between LMCAD and MPCAD. Further prospective investigations in larger populations are required to confirm these findings.

A reduction of CETP activity, not an increase, is associated with modestly impaired postprandial lipemia and increased HDL-cholesterol in adult asymptomatic women

Background

The relationship between CETP and postprandial hyperlipemia is still unclear. We verified the effects of varying activities of plasma CETP on postprandial lipemia and precocious atherosclerosis in asymptomatic adult women.

Methods

Twenty-eight women, selected from a healthy population sample (n = 148) were classified according to three CETP levels, all statistically different: CETP deficiency (CETPd ≤ 4.5%, n = 8), high activity (CETPi ≥ 23.8, n = 6) and controls (CTL, CETP ≥ 4.6% and ≤ 23.7%, n = 14). After a 12 h fast they underwent an oral fat tolerance test (40 g of fat/m² of body surface area) for 8 hours. TG, TG-rich-lipoproteins (TRL), cholesterol and TRL-TG measurements (AUC, AUIC, AR, RR and late peaks) and comparisons were performed on all time points. Lipases and phospholipids transfer protein (PLTP) were determined. Correlation between carotid atherosclerosis (c-IMT) and postprandial parameters was determined. CETP TaqIB and I405V and ApoE-ε3/ε2/ε4 polymorphisms were examined. To elucidate the regulation of increased lipemia in CETPd a multiple linear regression analysis was performed.

Results

In the CETPi and CTL groups, CETP activity was respectively 9 and 5.3 higher compared to the CETPd group. Concentrations of all HDL fractions and ApoA-I were higher in the CETPd group and clearance was delayed, as demonstrated by modified lipemia parameters (AUC, AUIC, RR, AR and late peaks and meal response patterns). LPL or HL deficiencies were not observed. No genetic determinants of CETP deficiency or of postprandial lipemia were found. Correlations with c-IMT in the CETPd group indicated postprandial pro-atherogenic associations. In CETPd the regression multivariate analysis (model A) showed that CETP was largely and negatively predicted by VLDL-C lipemia (R² = 92%) and much less by TG, LDL-C, ApoAI, phospholipids and non-HDL-C. CETP (model B) influenced mainly the increment in ApoB-100 containing lipoproteins (R² = 85% negatively) and phospholipids (R² = 13%), at the 6^thh point.

Conclusion

The moderate CETP deficiency phenotype included a paradoxically high HDL-C and its sub fractions (as earlier described), positive associations with c-IMT, a postprandial VLDL-C increment predicting negatively CETP activity and CETP activity regulating inversely the increment in ApoB100-containing lipoproteins. We hypothesize that the enrichment of TG content in triglyceride-rich ApoB-containing lipoproteins and in TG rich remnants increases lipoproteins' competition to active lipolysis sites,reducing their catabolism and resulting on postprandial lipemia with atherogenic consequences.

Association between CETP Taq1B and LIPC -514C/T polymorphisms with the serum lipid levels in a group of Tehran's population: a cross sectional study

BACKGROUND

Low level of high density lipoprotein cholesterol (HDL-C) has high prevalence in the Tehran Lipid and Glucose Study (TLGS) cohort. About 50% of the inter-individual variation in serum HDL-C levels is genetically determined. Polymorphisms in cholesteryl ester transfer protein (CETP) and hepatic lipase (LIPC) genes have been found to be associated with the metabolism and serum concentration of the HDL-C.

OBJECTIVES

To determine the association between Taq1B polymorphism in CETP gene and -514C/T polymorphism in LIPC gene with serum lipid levels and lipid peroxidation in a subgroup of the TLGS population.

RESULTS

Serum HDL-C level had significant association with CETP Taq1B polymorphism and B2B2 subjects had the highest HDL-C levels compared to B2B1 and B1B1 genotypes (37.9 vs. 36.9 and 35.3 mg/dl, respectively; P = 0.01). However, carriers of "B1" allele, in comparison to the non carriers (B2B2), had significantly lower levels of TC (200.1 vs. 215.2 mg/dl; P = 0.005), HDL-C (35.8 vs. 37.9 mg/dl; P = 0.009) and malondialdehyde MDA (4.5 vs. 5.0 nmol/mL; P=0.031). Carriers of the "T" allele in -514C/T polymorphism in LIPC gene had higher means of HDL-C than non carriers (37.7 vs. 35.7 mg/dl, P = 0.04). No other association was found between -514C/T polymorphism and any other serum lipids or MDA level.

CONCLUSION

This study demonstrates the association between Taq1B and -514C/T polymorphisms in the CETP and LIPC genes with the serum HDL-C levels.

TAQIB and I405V polymorphisms of CETP are moderately associated with obesity risk in the Chinese adult population

Associations between the TAQIB and I405V polymorphisms and obesity risk were studied for a single locus as well as in combination. A total of 934 obese subjects and 924 normal controls were included in the study. TAQIB was associated with high-density lipoprotein (HDL) levels (P < 0.001), while I405V was associated with levels of low-density lipoprotein (P = 0.03) and total cholesterol (P = 0.007). Less common alleles of TAQIB and I405V were associated with decreased obesity risk and further drops in odds ratio (OR) were observed in carriers with rare homozygous alleles on both loci (OR = 0.659, P = 0.02). The TAQIB B2 allele was associated with reductions in both hip circumference (P = 0.034) and triceps skinfold thickness (TST) (P = 0.045), although this effect was completely abolished after controlling for HDL levels. The 405V variant was associated with reductions in hip circumference (P = 0.031), body fat composition (P = 0.039) and TST (P = 0.036); these effects were weakened (P < 0.1) after controlling for HDL levels. In conclusion, less common alleles of TAQIB and I405V appear to be modestly associated with obesity risk in an adult Chinese population. Adjustments for HDL levels completely (TAQIB) or partially (I405V) abolished the observed association.

Gene-environment interactions of CETP gene variation in a high cardiovascular risk Mediterranean population

Genome-wide association studies show that cholesteryl ester transfer protein (CETP) single nucleotide polymorphisms (SNPs) are more strongly associated with HDL cholesterol (HDL-C) concentrations than any other loci across the genome. However, gene-environment interactions for clinical applications are still largely unknown. We studied gene-environment interactions between CETP SNPs and dietary fat intake, adherence to the Mediterranean diet, alcohol consumption, smoking, obesity, and diabetes on HDL-C in 4,210 high cardiovascular risk subjects from a Mediterranean population. We focused on the -4,502C>T and the TaqIB SNPs in partial linkage disequilibrium (D'= 0.88; P < 0.001). They were independently associated with higher HDL-C (P < 0.001); this clinically relevant association was greater when their diplotype was considered (14% higher in TT/B2B2 vs. CC/B1B1). No gene-gene interaction was observed. We also analyzed the association of these SNPs with blood pressure, and no clinically relevant associations were detected. No statistically significant interactions of these SNPs with obesity, diabetes, and smoking in determining HDL-C concentrations were found. Likewise, alcohol, dietary fat, and adherence to the Mediterranean diet did not statistically interact with the CETP variants (independently or as diplotype) in determining HDL-C. In conclusion, the strong association of the CETP SNPs and HDL-C was not statistically modified by diet or by the other environmental factors.

No interaction between alcohol consumption and HDL-related genes on HDL cholesterol levels

OBJECTIVE

To assess the relationships and possible interactions between polymorphisms related to HDL levels and alcohol consumption.

METHODS

Cross-sectional population-based study including 2863 women and 2546 men aged 35-75 years (CoLaus study). Alcohol intake was assessed by the reported alcohol consumption of the last 7 days. Nineteen candidate genes known to influence HDL levels were studied.

RESULTS

Alcohol consumption increased HDL cholesterol levels in both genders. After multivariate adjustment for gender, age, body mass index, smoking, hypolipidaemic drug treatment, physical activity and alcohol consumption, APOA5, CETP, LIPC and LPL gene polymorphisms were significantly (10(-5) threshold) related with HDL cholesterol levels, while no genexalcohol intake interaction was found for all SNPs studied. ABCA1 polymorphisms were related to HDL cholesterol levels on bivariate analysis but the relationship was no longer significant after multivariate analysis.

CONCLUSION

Our data confirm the association of alcohol consumption and of APOA5, CETP, LIPC and LPL gene polymorphisms with HDL cholesterol levels. Conversely, no genexalcohol consumption interactions were found, suggesting that the effect of alcohol consumption on HDL cholesterol levels is not mediated via a modulation of HDL related genes.

Genetic determinants of apolipoprotein B-100 kinetics

PURPOSE OF REVIEW

We review stable isotope tracer studies of apolipoprotein B-100 (apoB) kinetics concerning genetic polymorphisms and mutations that affect human lipoprotein metabolism.

RECENT FINDINGS

In obese men, the allelic combination of the apoB signal peptide, SP24, and cholesteryl ester transfer protein, CETP B1B1, is independently associated with lower VLDL apoB secretion. Microsomal triglyceride transfer protein -493G/T carriers have reduced IDL apoB and LDL apoB production as compared with controls. Mutations in cholesterol transporters (ATP-binding cassette transporter G8 and Niemann-Pick C1 Like 1) are associated with reduced VLDL apoB secretion and increased LDL apoB production and catabolism. The ATP-binding cassette transporter G8 400K variant is a significant, independent predictor of VLDL apoB secretion. Mutations in lipases (lipoprotein lipase and hepatic lipase) and transfer proteins (lecithin-cholesterol acyltransferase and cholesteryl ester transfer protein) alter their functional activity, which impact on VLDL and LDL kinetics.

SUMMARY

Mutations in genes that regulate intrahepatic apoB assembly and lipid substrate availability to the liver impact on VLDL apoB secretion. Lipoprotein tracer studies can provide functional insight into the potential impact of genetic polymorphisms in regulating apoB metabolism in humans.

Common cholesteryl ester transfer protein gene variation related to high-density lipoprotein cholesterol is not associated with decreased coronary heart disease risk after a 10-year follow-up in a Mediterranean cohort: Modulation by alcohol consumption

OBJECTIVE

Despite the consistent association between cholesteryl ester transfer protein (CETP) gene variation and plasma HDL-C, huge controversy still rages on its association with coronary heart disease (CHD). We investigated the association between the CETP-TaqIB polymorphism, HDL-C and incident CHD in a Mediterranean population.

METHODS

A nested case-control study among participants of the Spanish EPIC cohort was performed. 41,440 healthy individuals (30-69 years) were followed up over a 10-year period, incident CHD cases being identified. We analyzed 557 confirmed CHD cases and 1180 healthy controls.

RESULTS

Despite B2B2 subjects having the highest HDL-C concentrations and B1B1, the lowest (P<0.001), no protective effect of the B2 allele against CHD incidence was observed. Thus, in comparison with B1B1 subjects, the adjusted CHD risk of B1B2 was OR: 1.00, 95% CI: 0.80-1.26; P=0.982, and that of B2B2 was OR: 1.16, 95% CI: 0.84-1.61; P=0.374. These results did not change after adjustment for HDL-C. No significant interaction between alcohol consumption and the CETP-TaqIB polymorphism in determining HDL-C was found. However, a different effect of this polymorphism on CHD risk in drinkers and non-drinkers was observed. In non-drinkers, the B2B2 genotype was associated with a non-significant lower CHD risk, whereas in drinkers it was associated with a greater risk (OR: 1.55, 95% CI: 1.05-2.29; P=0.026). We also observed that in diabetics (11% cases and 7.4% controls), the B2 allele was significantly associated with higher CHD risk.

CONCLUSIONS

In this Mediterranean population, the CETP-TaqIB polymorphism was not associated with a lower CHD incidence, and its effect was modulated by alcohol and possibly by diabetes.

Cholesteryl ester transfer protein gene polymorphisms and longevity syndrome

Purpose:

High levels of high density lipoprotein (HDL) cholesterol are associated with a decreased risk of coronary heart disease (CHD). Subjects with high levels of HDL cholesterol (>70 mg/dl; 1.79 mmol/l) as well as high levels of low density lipoprotein (LDL) cholesterol, could represent a group with longevity syndrome (LS). Since HDL particles are influenced by cholesteryl ester transfer protein (CETP) activity, it is worth studying the CETP polymorphism. The aim of the study was to detect whether 2 genetic variants of the CETP are associated with the LS.

Subjects and Methods:

The study population consisted of 136 unrelated men and women with no personal and family history of CHD; 69 met the criteria for LS and 67 did not meet these criteria and had “normal” HDL cholesterol (>40 and <70 mg/dl; >1.03 and <1.79 mmol/l). All patients were genotyped for the TaqIB and I405V polymorphisms.

Results:

The B2 allele frequency of TaqIB polymorphism was higher in the LS in comparison with the non-LS group (p=0.03) whereas B1 allele frequency was higher in the non-LS group (p=0.03).

Conclusions:

Gene polymorphisms could help decide whether individuals who have increased levels of both LDL cholesterol and HDL cholesterol require treatment. Some of the prerequisites could include that subjects with LS should not only have very high levels of HDL cholesterol but also favorable gene polymorphisms. However, further investigations with a larger sample and including other gene polymorphisms, are needed.

The influence of nutrigenetics on the lipid profile: interaction between genes and dietary habits

Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.

Effects of V279F in the Lp-PLA(2) gene on markers of oxidative stress and inflammation in Koreans

BACKGROUND

A single nucleotide polymorphism (SNP), V279F, in the lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) gene is known to influence enzyme activity. It is unclear whether Lp-PLA(2) exerts pro- or antiatherogenic effects in humans. We investigated the interplay between V279F, Lp-PLA(2) activity, oxidative stress and inflammation.

METHODS

We genotyped 2914 healthy Koreans (43-79years) for the Lp-PLA(2) V279F and measured anthropometric parameters, lipid profile, fatty acid composition, lipid peroxides, inflammatory markers and Lp-PLA(2) levels.

RESULTS

Lp-PLA(2) activity was 24% lower in V/F subjects (n=641) than in those with the V/V genotype (n=2227). Enzyme activity was undetectable in F/F subjects. Lp-PLA(2) activity was positively correlated with LDL-cholesterol (r=0.134, P<0.001), ox-LDL (r=0.064, P<0.01), 8-epi-PGF(2alpha) (r=0.198, P<0.001), free fatty acid (r=0.082, P<0.001), and fibrinogen (r=0.112, P<0.01) levels. Additionally, ox-LDL, 8-epi-PGF(2alpha), free fatty acid, and fibrinogen levels were positively correlated with hs-CRP. V279F was associated with LDL-cholesterol and arachidonic acid (AA) in serum phospholipid. F/F subjects had lower LDL-cholesterol than V/V subjects (V/V: 120.9+/-0.69, V/F: 119.4+/-1.26, F/F: 109.2+/-4.84mg/dl, P=0.025). A significant association between the F/F genotype and increasing AA in serum phospholipids was found in subjects with high LDL-cholesterol (> or =130mg/dl) (P=0.003) but not in those with low LDL-cholesterol (<130mg/dl). F/F subjects in the high LDL-cholesterol group had CRP concentrations about three times higher than those with V/V or V/F genotypes (V/V: 1.25+/-0.09, V/F: 0.97+/-0.12, F/F: 3.20+/-0.88mg/dl, P<0.001).

CONCLUSIONS

The recessive effects of Lp-PLA(2) V279F on LDL-cholesterol and significant correlations between Lp-PLA(2) activity and LDL-cholesterol, 8-epi-PGF(2alpha) and fibrinogen support a pro-oxidative or pro-atherogenic role for this enzyme. Paradoxically, the combination of the complete deficiency of Lp-PLA(2) activity and high LDL-cholesterol enhanced lipid peroxidation and inflammation.

Association of two CETP polymorphisms with HDL levels in the Chinese obese population

The association of two cholesterol ester transfer protein (CETP) polymorphisms, D442G and TAQIB (B1-->B2), with high-density lipoprotein (HDL) levels in 932 Chinese obese individuals (BMI >or= 27) was investigated in comparison with normal controls (BMI <or= 24). Independent association was demonstrated for TAQIB minor allele B2 and CETP442 minor allele G with elevated HDL levels. The CETP D442G polymorphism was associated with a much greater increase in HDL levels in subjects with BMI exceeding 27 kg/m(2) (+5.42 mg/dl, P = 0.0007) compared to normal controls (+1.97 mg/dl, P = 0.275), and the increase in HDL reached the highest level among subjects with BMI exceeding 30 kg/m(2) (+6.80 mg/dl, P = 0.016). TAQIB showed significant association with HDL levels only in normal BMI subgroup (P = 0.0017). TAQIB significantly interacted with serum triglyceride (TG) on modulating HDL levels (P = 0.027). The TAQIB-TG interaction effect remained marginally significant after controlling for BMI (P = 0.057). We conclude that D442G polymorphism is associated with more HDL elevation in obesity. TAQIB interacts with serum TG on modulating HDL levels, and the interaction is partly independent of BMI.