Cholesteryl ester transfer protein TaqIB variant, high-density lipoprotein cholesterol levels, cardiovascular risk, and efficacy of pravastatin treatment: individual patient meta-analysis of 13,677 subjects

Cholesterol Ester Transfer Protein Taq1B Polymorphism and Its Association with Cardiovascular Risk Factors in Patients Undergoing Angiography in Yazd, Eastern Iran: A Cross-Sectional Study

Background

Several studies assessed the relationship between the cholesterol ester transfer protein (CETP) Taq1B gene polymorphism (rs708272) with risk factors of cardiovascular diseases (CVDs). However, their findings were inconsistent. The present study investigated the relationship between CVD risk factors and the Taq1B variant in patients undergoing coronary angiography.

Methods

This cross-sectional study was conducted on 476 patients aged 30-76 years old of both sexes from 2020-2021, in Yazd (Iran). The Taq1B polymorphism genotypes were evaluated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on DNA extracted from whole blood. Standard protocols were used to measure cardio-metabolic markers. To determine the association between CVDs risk factors and the rs708272 variant, binary logistic regression was used in crude and adjusted models.

Results

Taq1B polymorphism genotype frequencies were 10.7% for B1B1, 72.3% for B1B2, and 17% for B2B2. There was no significant association between abnormal levels of CVDs risk factors and different genotypes of the Taq1B variant, Gensini score (P=0.64), Syntax score (P=0.79), systolic blood pressure (P=0.55), diastolic blood pressure (P=0.58), and waist circumference (P=0.79). There was no significant association between genotypes of the rs708272 variant and any abnormal serum lipid levels. After adjusting for confounders, the results remained non-significant.

Conclusion

There was no significant association between CVDs risk factors and CETP rs708272 polymorphism. The relationship between CETP gene variants and CVD occurrences varied across groups, implying that more research in different regions is required.A preprint version of this manuscript is available at https://www.researchsquare.com/article/rs-2575215/v1 with doi: 10.21203/rs.3.rs-2575215/v1.

Dietary antioxidant status indices may not interact with CETP Taq1B polymorphism on lipid profile and severity of coronary artery stenosis in patients under coronary angiography

The association of CETP Taq1B polymorphism with some metabolic traits is still controversial. The interaction of adherence to dietary indices with this polymorphism on the severity of coronary artery stenosis and serum lipid parameters needs to be investigated. This study aimed to test this hypothesis. This cross-sectional study included 453 patients who were referred from Afshar Hospital of Yazd and undergoing coronary angiography from 2020 to 2021. Dietary intake was evaluated by a 178-item validated and reliable dietary questionnaire. Dietary indices such as dietary antioxidant index (DAI), dietary antioxidant quality score (DAQS), and dietary phytochemical index (DPI) are determined according to dietary guidelines. The Taq1B variant was genotyped by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Two-way ANOVA was used to test the interaction between Taq1B polymorphism and dietary indices. The results of the frequency analysis of Taq1B genotypes showed that 10.4% were B1B1, 72.4% B1B2, and 17.2% B2B2. No significant interaction was found between the Taq1B variant with high adherence to DAQS, DAI, and DPI on total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG) levels, and Gensini score (GS) and Syntax score (SS). In high-adherence dietary indices, lipid profile and coronary artery stenosis scores did not differ significantly in Taq1B genotypes. Due to the insignificant results in this research, further studies are needed to investigate the role of Taq1B SNP in modulating dyslipidemia and the severity of the CAD in interaction with dietary indices.

Interaction between CETP Taq1B polymorphism and dietary patterns on lipid profile and severity of coronary arteries stenosis in patients under coronary angiography: a cross-sectional study

AIM

Evidence indicates there are still conflicts regarding CETP Taq1B polymorphism and coronary artery disease risk factors. Current findings about whether dietary patterns can change the relationship of the Taq1B on lipid profile and the severity of coronary arteries stenosis appears to be limited. The present research made an attempt to investigate this possible relationship.

METHODS

This cross-sectional study involved 453 male and female participants with a mean age of 57 years. A validated 178-item food frequency questionnaire (FFQ) was used to assess dietary usual intake. Dietary patterns were extracted through principal component analysis (PCA). Taq1B variant was genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Two-way ANOVA was used to test the interaction between Taq1B polymorphism and dietary patterns.

RESULTS

Two dietary patterns were detected: the western dietary pattern (WDP) and the traditional dietary pattern (TDP). The frequency of Taq1B genotypes turned out to be 10.4, 72.4, and 17.2% for B1B1, B1B2, and B2B2, respectively. A significant difference was observed in TG and TG/HDL-C levels among TaqIB genotypes in higher adherence to TDP (P = 0.01 and P = 0.03, respectively). Taq1B showed a significant interaction with TDP for modulating TG levels and TG/HDL-C ratio (P = 0.02 and P = 0.04, respectively). Greater compliance to WDP demonstrated a significant difference in TG and TG/HDL-C levels across rs708272 genotypes (P = 0.03) after adjusting for confounding factors. Other lipid components and coronary arteries stenosis scores failed to show any relationship or significant difference across Taq1B genotypes or dietary patterns.

CONCLUSION

Adherence to TDP may adjust the association between the Taq1B variant and TG and TG/HDL-C levels in patients undergoing coronary angiography. To better understand the relationships, we suggest prospective studies in different race groups with multivariate approaches.

Gender Differences in Insulin Resistance: New Knowledge and Perspectives

Insulin resistance is the main mechanism in a whole series of pathological conditions, which are not only of metabolic interest but also of a systemic type. This phenomenon means that the body's cells become less sensitive to the hormone insulin, leading to higher levels of insulin in the blood. Insulin resistance is a phenomenon that can be found in both men and women and in particular, in the latter, it is found mainly after menopause. Premenopause, hormonal fluctuations during the menstrual cycle, and the presence of estrogen can affect insulin sensitivity. Androgens, such as testosterone, are typically higher in men and can contribute to insulin resistance. In both sexes, different human body types affect the distribution and location of body fat, also influencing the development of diabetes and cardiovascular disease. Insulin resistance is also associated with some neurological and neurogenerative disorders, polycystic ovary syndrome, atherosclerosis, and some of the main neoplastic pathologies. A healthy lifestyle, including regular physical activity, a balanced diet, and self-maintenance, can help to prevent the onset of insulin resistance, regardless of gender, although the different habits between men and women greatly affect the implementation of preventative guidelines that help in fighting the manifestations of this metabolic disorder. This review may help to shed light on gender differences in metabolic diseases by placing a necessary focus on personalized medical management and by inspiring differentiated therapeutic approaches.

No association between LDL receptor and CETP genetic variants and atorvastatin response in Jordanian hyperlipidemic patients

OBJECTIVES

Atorvastatin is commonly used medication to achieve low levels of low-density lipoproteins (LDL). Cholesteryl ester transfer protein (CETP) and LDL receptor (LDLR) genetic variants can affect the cholesterol transport and hence may affect on atorvastatin response. This study aimed to investigate the influence of LDLR AvaII, CETP TaqIb, and Rs1532624 on the efficacy of 20 mg atorvastatin among Jordanian hyperlipidemic patients.

METHODS

One hundred and 50 blood samples were collected from hyperlipidemic patients in the University of Jordan Hospital. Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping of LDLR AvaII and CETP TaqIb genetic variants. The genotyping of CETP Rs1532624 variant was done by Sanger DNA-Sequencing.

RESULTS

LDLR AvaII and CETP TaqIb and Rs1532624 variants showed a significant (p value < 0.05) association with the baseline of the LDL at the time of diagnoses. On the other hand, none of the tested genetic variants showed a significant (p value>0.05) association with LDL reduction after atorvastatin therapy.

CONCLUSIONS

Results demonstrated a significant association between the LDLR AvaII and CETP TaqIb, and Rs1532624 genetic variants with the LDL baseline level. However, the atorvastatin therapy among hyperlipidemic patients of Jordanian origin was not affected by any of the tested variants.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

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.

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

The combined effects of cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism and canola, sesame and sesame-canola oils consumption on metabolic response in patients with diabetes and healthy people

Introduction: Cholesteryl ester transfer protein (CETP) is a key regulating enzyme in the lipid metabolism pathway, and its gene polymorphism may be a candidate for modulating the metabolic responses to dietary intervention. We thus examined whether the effects of the CETP TaqIB polymorphism on metabolic profiles were modified by dietary plant oils.

Methods: This is a retrospective analysis of data collected during a randomized triple-blind cross over trial. A total of 95 patients with type 2 diabetes and 73 non-diabetes individuals completed a 9-weekof the intake of sesame, canola and sesame-canola oils. Blood samples were collected at the beginning and at the end of each intervention period for biochemical analysis. Genotyping was done using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results: In diabetes patients, B1B1 homozygotes of the CETP TaqIB polymorphism compared with B2 carriers (B1B2 + B2B2) had significantly lower diastolic blood pressure, apoB and apoB: apoA-1,and higher Lp(a) after the intake of sesame-canola oil, as well as lower insulin and HOMA-IR after the intake of sesame oil. There was also a significant effect of genotype on adjusted changes of apoB, apoB: apoA-1, insulin, HOMA-IR and QUICKI. A significant genotype-dietary oils combined effects were observed for diastolic blood pressure, and LDL: HDL, TC: HDL and TG: HDL ratios in diabetes patients. No independent or combined effects of dietary oils and genotypes on outcomes were found in healthy people.

Conclusion: There was a modulatory effect of the CETP TaqIB polymorphism on some metabolic traits in response to plant oils in patients with diabetes. Taken together, the intake of sesame-canola and canola oils showed more favorable effects in diabetes patients with B1B1 genotype. Future investigations are needed to confirm these results.

Common genetic variation in obesity, lipid transfer genes and risk of Metabolic Syndrome: Results from IDEFICS/I.Family study and meta-analysis

As the prevalence of metabolic syndrome (MetS) in children and young adults is increasing, a better understanding of genetics that underlie MetS will provide critical insights into the origin of the disease. We examined associations of common genetic variants and repeated MetS score from early childhood to adolescence in a pan-European, prospective IDEFICS/I.Family cohort study with baseline survey and follow-up examinations after two and six years. We tested associations in 3067 children using a linear mixed model and confirmed the results with meta-analysis of identified SNPs. With a stringent Bonferroni adjustment for multiple comparisons we obtained significant associations(p < 1.4 × 10⁻⁴) for 5 SNPs, which were in high LD (r² > 0.85) in the 16q12.2 non-coding intronic chromosomal region of FTO gene with strongest association observed for rs8050136 (effect size(β) = 0.31, p_Wald = 1.52 × 10⁻⁵). We also observed a strong association of rs708272 in CETP with increased HDL (p = 5.63 × 10⁻⁴⁰) and decreased TRG (p = 9.60 × 10⁻⁵) levels. These findings along with meta-analysis advance etiologic understanding of childhood MetS, highlighting that genetic predisposition to MetS is largely driven by genes of obesity and lipid metabolism. Inclusion of the associated genetic variants in polygenic scores for MetS may prove to be fundamental for identifying children and subsequently adults of the high-risk group to allow earlier targeted interventions.

Cholesteryl ester transfer protein: the physiological and molecular characteristics in the pathogenesis of atherosclerosis and Alzheimer’s disease

Cholesteryl ester transfer protein (CETP) is involved in reverse cholesterol transport, mediates the exchange of cholesteryl esters for triglycerides between high-density lipoproteinsand low-density lipoproteins/very low-density lipoproteins. Lipid transfer mechanism by CETP is unknown. Two main models have been proposed for the mechanism of action of CETP: shuttle and tunnel mechanisms. The variants of CETP gene affect activity and level of protein, thus they are associated with lipid profile and risk of many diseases. Some clinical studies reported that polymorphisms of CETP, including TaqIB and I405V, are associated with risk of atherosclerosis and/or Alzheimer’s disease. CETP plays important role an in the metabolism of cholesterol, thus is correlated with pathomechanism of coronary artery disease. Inhibition of CETP can be an effective strategy to improve the lipid profile and reduce risk of cardiovascular diseases. Therefore, new therapeutic strategies to reduce activity of CETP or decrease its level are developed. Effectiveness of following pharmacological methods of modulation of CETP activity was studied: anti-CETP vaccines, antisense oligonucleotide and small molecule inhibitors of CETP. This article presents an overview of the literature on the correlation between cardiovascular diseases and CETP protein/CETP gene. Furthermore, it discusses the impact of CETP on pathogenesis of Alzheimer’s disease.

Genetics, Dyslipidemia, and Cardiovascular Disease: New Insights

PURPOSE OF REVIEW

The cardiovascular (CV) risk related to lipid disorders is well established and is based on a robust body of evidence from well-designed randomized clinical trials, as well as prospective observational studies. In the last two decades, significant advances have been made in understanding the genetic basis of dyslipidemias. The present review is intended as a comprehensive discussion of current knowledge about the genetics and pathophysiology of disorders that predispose to dyslipidemia. We also focus on issues related to statins and the proprotein convertase subtilisin/kexin type 9 (PCSK9) and some of its polymorphisms, as well as new cholesterol-lowering medications, including PCSK9 inhibitors.

RECENT FINDING

Cholesterol is essential for the proper functioning of several body systems. However, dyslipidemia-especially elevated low-density lipoprotein (LDL-c) and triglyceride levels, as well as reduced lipoprotein lipase activity-is associated with an increased risk of coronary artery disease (CAD). High-density lipoprotein (HDL-c), however, seems to play a role as a risk marker rather than as a causal factor of the disease, as suggested by Mendelian randomization studies. Several polymorphisms in the lipoprotein lipase locus have been described and are associated with variations in the activity of this enzyme, producing high concentrations of triglycerides and increased risk of CAD. Dyslipidemia, especially increased LDL-c and triglyceride levels, continues to play a significant role in CV risk. The combination of genetic testing and counseling is important in the management of patients with dyslipidemia of genetic etiology. Strategies focused on primary prevention can offer an opportunity to reduce CV events.

Association of APOE and CETP TaqIB Polymorphisms with Type 2 Diabetes Mellitus

Apolipoprotein E (APOE) and cholesteryl ester transfer protein (CETP) play an important role in the lipid metabolism. Dyslipidemia is one of the complications that found in type 2 diabetes mellitus (T2DM) patients. The aim of this study was to investigate the association of APOE and CETP TaqIB polymorphisms with T2DM and its related metabolic parameters in Southern Thai population. Study subjects were 241 T2DM patients and 275 healthy controls. The APOE and CETP TaqIB polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. APOE polymorphism showed a statistical difference in allele frequencies (p = 0.025) and genotype distributions (p <0.001) between T2DM patients and healthy controls. The E4 carriers were associated with a significantly higher TC, and/or LDL-C levels compared to the E2 and E3 carriers, respectively in all subjects and healthy controls. Moreover, CETP TaqIB B2B2 genotype was significantly higher HDL-C levels compared with B1B1, and B1B2 genotypes in all subjects, and T2DM patients. Multiple logistic regression analysis showed that APOE and CETP TaqIB polymorphisms were not associated with T2DM. In conclusion, APOE and CETP TaqIB polymorphisms might not be the genetic risk factors for T2DM in Southern Thai population, however, APOE and CETP TaqIB polymorphisms were associated with serum lipids in healthy controls and T2DM, respectively.

Endothelial nitric oxide synthase Glu 298 Asp (G894T) and Apolipoprotein E gene polymorphism as possible risk factors for coronary heart disease among Egyptians

In Egypt, The prevalence of chronic heart disease (CHD) is 8.3%. It is the principal cause of death and is responsible for 22% of total mortality. The age-adjusted mortality rate is 174 per 100,000 of population. There are many studies on traditional risk factors and CHD in Egypt but the study of novel risk factors is deficient.

Objectives

The aim of the present case control study was to investigate the relation between CHD susceptibility and Endothelial Nitric Oxide Synthase (eNOS) Glu 298 Asp (G894T) and Apolipoprotein E (ApoE) gene polymorphism in a cohort of Egyptian individuals.

Methods

Genotyping of eNOS (Glu298Asp) and Apo E genes polymorphisms were done using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method for 100 CHD cases and 100 age and sex matched healthy controls.

Results

A statistically significant association was observed between GT and TT genotypes of endothelial nitric oxide synthase gene with CHD with OR = 2.03 and 3.5; respectively. Also, carriers of E4 allele and especially E3/E4 genotype were at higher risk of CHD with OR = 3.3 for both. Significant association was also observed between the presence of combined GTE3E4 genotype and CHD with OR = 6.6.

Conclusion

GT and TT genotypes of endothelial nitric oxide synthase gene, E3/E4 genotype of Apo E gene polymorphism and combined GTE3E4 genotype can be considered risk factors for the development of CHD among Egyptians.

Interaction between endothelial nitric oxide synthase rs1799983, cholesteryl ester-transfer protein rs708272 and angiopoietin-like protein 8 rs2278426 gene variants highly elevates the risk of type 2 diabetes mellitus and cardiovascular disease

Background

The aim of the present study was to examine the association of angiopoietin-like proteins-8 (ANGPTL8) rs2278426, cholesteryl ester-transfer protein (CETP) rs708272 and endothelial nitric oxide synthase (NOS3) rs1799983 variants with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), and to investigate the effect of the potential interaction between these variants on disease risk.

Methods

Our study included 272 subjects classified into 68 patients with T2DM, 68 patients with T2DM complicated with CVD and 136 control subjects. ANGPTL8 c194C>T, CETP Taq1B and NOS3 G894T polymorphisms were genotyped using TaqMan^® SNP Genotyping Assay.

Results

The presence of NOS3, ANGPTL8, and homozygous CETP B1 variants were associated with increased risk of T2DM by 3.07-, 2.33- and 1.75-fold, respectively. NOS3 variant was associated with 3.08-fold increased risk of CVD (95% CI 1.70–5.60), while ANGPTL8 C allele was associated with 2.8-fold increased risk of CVD in T2DM patients (95% CI 1.13–6.97). Concomitant presence of both, CETP B1 and NOS3 T allele, associated with increased risk of T2DM, CVD and CVD in T2DM by 8.36-, 6.33- and 7.87-fold, respectively, while concomitant presence of ANGPTL8 variant with either CETP B1 or NOS3 T allele was not associated with increased risk of T2DM or CVD. However, concomitant presence of the three variants together elevated the risk of T2DM by 13.22-fold (p = 0.004), CVD risk by 8.86-fold (p = 0.03) and highly elevated the risk of CVD in T2DM patients by 13.8-fold (p = 0.008).

Conclusions

Concomitant presence of CETP B1, NOS3 T and ANGPTL8 T alleles augments the risk of CVD and T2DM. Further studies to clarify the mechanism of gene–gene interaction in the pathogenesis of CVD and T2DM are needed.

Navigating the Future of Cardiovascular Drug Development-Leveraging Novel Approaches to Drive Innovation and Drug Discovery: Summary of Findings from the Novel Cardiovascular Therapeutics Conference

PURPOSE

The need for novel approaches to cardiovascular drug development served as the impetus to convene an open meeting of experts from the pharmaceutical industry and academia to assess the challenges and develop solutions for drug discovery in cardiovascular disease.

METHODS

The Novel Cardiovascular Therapeutics Summit first reviewed recent examples of ongoing or recently completed programs translating basic science observations to targeted drug development, highlighting successes (protein convertase sutilisin/kexin type 9 [PCSK9] and neprilysin inhibition) and targets still under evaluation (cholesteryl ester transfer protein [CETP] inhibition), with the hope of gleaning key lessons to successful drug development in the current era. Participants then reviewed the use of innovative approaches being explored to facilitate rapid and more cost-efficient evaluations of drug candidates in a short timeframe.

RESULTS

We summarize observations gleaned from this summit and offer insight into future cardiovascular drug development.

CONCLUSIONS

The rapid development in genetic and high-throughput drug evaluation technologies, coupled with new approaches to rapidly evaluate potential cardiovascular therapies with in vitro techniques, offer opportunities to identify new drug targets for cardiovascular disease, study new therapies with better efficiency and higher throughput in the preclinical setting, and more rapidly bring the most promising therapies to human testing. However, there must be a critical interface between industry and academia to guide the future of cardiovascular drug development. The shared interest among academic institutions and pharmaceutical companies in developing promising therapies to address unmet clinical needs for patients with cardiovascular disease underlies and guides innovation and discovery platforms that are significantly altering the landscape of cardiovascular drug development.

Cholesteryl ester transfer protein gene variations and macronutrient intakes interaction in relation to metabolic syndrome: Tehran lipid and glucose study

Objective(s):

There are controversial results regarding the effect of the interaction of CETP polymorphisms with dietary fats on the lipid profiles. The aim of this study was to examine the effect of CETP polymorphisms (rs5882 and rs3764261) and macronutrient intakes interaction in relation to metabolic syndrome (MetS) or its components.

Materials and Methods:

In this nested case-control study, subjects were selected from among participants of the Tehran Lipid and Glucose Study. Cases (n=441) were individually matched with two controls (844 non-MetS subjects). DNA samples were genotyped with HumanOmniExpress-24-v1-0 bead chips, including 649,932 SNP loci.

Results:

The mean ages at baseline were 38.1±10 and 37.0±10 years in women and 36.2±11 and 36.3±11 years in men, respectively in cases and controls. We did not find significant gene-diet interactions between rs5882 and dietary macronutrient intakes in relation to MetS risk. The risk of low HDL-C was lower in the first quartile of MUFA and total fat intake in G allele carriers, compared to AA genotype group. The risk of high BP appeared to increase significantly in higher quartiles of trans-fatty acid intakes (>1.81% of total energy intake) in G allele carriers compared with the AA genotype group. No significant interactions were found between rs3764261 and macronutrient intakes in association with MetS or its components.

Conclusion:

Our findings demonstrate that dietary fats modify the association of rs5882 and risk of low HDL-C and high blood pressure.

Genetic variations of cholesteryl ester transfer protein and diet interactions in relation to lipid profiles and coronary heart disease: a systematic review

Data on diet–genotype interactions in the prevention or treatment of dyslipidemia have increased remarkably. This systematic review aimed to assess nutrigenetic studies regarding the modulating effect of diet on cholesteryl ester transfer protein (CETP) polymorphisms in relation to metabolic traits.

Data were collected through studies published between 2000 and SEP. 2016 using five electronic databases. The quality of eligible studies was assessed using a 12-item quality checklist, derived from the STrengthening the REporting of Genetic Association Studies (STREGA) statement. CETP variants that had associations with lipid profiles in previous studies were extracted for drawing of the linkage disequilibrium (LD) plot.

Among CETP variants, the rs9989419 best represented this genome wide association signal across all populations, based on LD r² estimates from 1000 genomes references. In the 23 found eligible studies (clinical trials and observational), the TaqIB and I405V polymorphisms were the two most intensively studied. Two studies reported the effect of interaction between rs3764261 and diet on lipid levels. Regarding the rs708272 (Taq1B), individuals with the B1 risk allele showed better responses to dietary interventions than those with B2B2 genotype, whereas with I405V, inconsistent results have been reported. Modest alcohol consumption was associated with decreased risk of coronary heart disease among B2 carriers of rs708272.

It is concluded that variations in the CETP gene may modulate the effects of dietary components on metabolic traits. These results have been controversial, indicating complex polygenic factors in metabolic response to diet and lack of uniformity in the study conditions and designs.

Dyslipidemia: Genetics, lipoprotein lipase and HindIII polymorphism

The direct link between lipid metabolism alterations and the increase of cardiovascular risk are well documented. Dyslipidemias, including isolated high LDL-c or mixed dyslipidemia, such as those seen in diabetes (hypertriglyceridemia, high LDL-c or low HDL-c), correlate with a significant risk of cardiovascular and cerebrovascular disease worldwide.  This review analyzes the current knowledge concerning the genetic basis of lipid metabolism alterations, emphasizing lipoprotein lipase gene mutations and the HindIII polymorphism, which are associated with decreased levels of triglycerides and LDL-c, as well as higher levels of HDL-c. These patterns would be associated with decreased global morbidity and mortality, providing protection against cardiovascular and cerebrovascular diseases.

Dyslipidemia: Genetics, lipoprotein lipase and HindIII polymorphism

The direct link between lipid metabolism alterations and the increase of cardiovascular risk are well documented. Dyslipidemias, including isolated high LDL-c or mixed dyslipidemia, such as those seen in diabetes (hypertriglyceridemia, high LDL-c or low HDL-c), correlate with a significant risk of cardiovascular and cerebrovascular disease worldwide.  This review analyzes the current knowledge concerning the genetic basis of lipid metabolism alterations, emphasizing lipoprotein lipase gene mutations and the HindIII polymorphism, which are associated with decreased levels of triglycerides and LDL-c, as well as higher levels of HDL-c. These patterns would be associated with decreased global morbidity and mortality, providing protection against cardiovascular and cerebrovascular diseases.

HDL subclasses and the common CETP TaqIB variant predict the incidence of microangiopatic complications in type 2 diabetic women: A 9years follow-up study

AIMS

Diabetic kidney disease (DKD) and retinopathy (DR) develop in a considerable number of subjects with Type 2 Diabetes (T2D) despite the achievement of the recommended targets for glycaemia and blood pressure. Atherogenic dyslipidemia may play a relevant role, especially in T2DM women.

METHODS

We report our findings on the effect of diabetic dyslipidaemia, the HDL subclasses distribution and the common cholesteryl ester transfer protein (CETP)TaqIB variant on the incidence or the progression of DKD and DR in 97 T2D women, after a ∼9years of follow-up.

RESULTS

At baseline, T2D women presented with low HDL-C levels and higher levels of large lipid rich α-1 (16.34mg/dl), α-2 (33.39mg/dl) and pre- α1 (4.81mg/dl) HDL subparticles. The CETP TaqIB polymorphism and baseline HbA1c, triglycerides, and HDL-C levels as well as specific HDL subpopulations were associated to the occurrence of RD after ∼9years of follow-up. At stepwise regression analysis, HbA1c, triglycerides and the less atheroprotective α-3 HDL particles were the only factors independently associated to the incidence of RD. These same variables were also associated with the progression from background to proliferative RD. BMI, LDL/HDL ratio and low levels of α-1 HDL particles were associated to the occurrence of DKD at univariate analysis, although BMI was the only significant predictor at stepwise multivariate regression analysis.

CONCLUSIONS

In T2D women, atherogenic dyslipidemia as well as subtle modifications in lipoprotein particles profile are associated with incidence and progression of microvascular disease.

Logic Regression Analysis of Gene Polymorphisms and HDL Levels in a Nationally Representative Sample of Iranian Adolescents: The CASPIAN-III Study

BACKGROUND

To investigate the associations of genetic polymorphism with high-density lipoprotein-cholesterol (HDL-C) levels in Iranian adolescents.

METHODS

This multicentre study was conducted on 10 - 18 year-old students from 27 provinces in Iran. Logic regression approach was used to determine the main effects and interactions of polymorphisms related to HDL-C levels.

RESULTS

The rs708272 polymorphism was significantly related to HDL-C levels. Moreover, rs708272 increased HDL-C levels and had a protective effect on HDL-C. The interaction of rs2230808 and rs5880 polymorphisms as well as the interaction of rs320 and rs708272 polymorphisms were associated with lower HDL-C levels. Furthermore, the interaction of rs320 and rs1801177 polymorphisms was associated with lower HDL-C levels.

CONCLUSIONS

We found that not only single SNPs, but also interactions of several SNPs affect HDL-C levels. Given the high prevalence of low HDL-C in Middle Eastern populations, further genetic studies are required for detailed analysis.

Association between Six CETP Polymorphisms and Metabolic Syndrome in Uyghur Adults from Xinjiang, China

OBJECTIVE

To explore the association between CETP gene polymorphisms and metabolic syndrome (MS), as well as the relationship between the CETP gene polymorphisms and each component of MS.

METHODS

A total of 571 individuals which were randomly selected from 5692 Uyghur adults were subdivided into two groups, including 280 patients with MS and 291 control subjects, using the group-matching method after matching for gender. We detected CETP polymorphisms (rs5882, rs1800775, rs3764261, rs12149545, rs711752, and rs708272) by using the Snapshot method.

RESULTS

(1) Significant differences were found involving the frequency distribution of genotypes and alleles of rs1800775, rs3764261, rs12149545, rs711752, and rs708272 between the control and MS groups (all p < 0.05). (2) rs1800775, rs3764261, rs12149545, rs711752, and rs708272 polymorphisms were significantly related to the risk of MS (all p < 0.05). (3) The rs1800775 polymorphism was associated with high fasting blood glucose levels and low high density lipoprotein cholesterol (HDL-C); rs3764261 and rs12149545 polymorphisms were associated with all components of MS except high blood pressure; rs711752 and rs708272 polymorphisms were associated with low HDL-C (all p < 0.05). (4) Complete linkage disequilibrium (LD) was identified for two pairs of single nucleotide polymorphisms (SNPs) (rs3764261 and rs12149545 (D' = 1.000, r² = 0.931), rs711752 and rs708272 (D' = 1.000, r² = 0.996)). (5) The A-G-G-G-C (p = 0.013, odds ratio [OR] = 0.622, 95% confidence interval [95% CI] = 0.427-0.906) and A-T-A-A-T (p < 0.001, OR = 0.519, 95% CI = 0.386-0.697) haplotypes were more frequent in the control group than in the case group. Conclusions: The rs1800775, rs3764261, rs12149545, rs711752, and rs708272 polymorphisms of CETP were associated with MS and its components among the Uyghur ethnic group. Complete LD was found between two pairs of SNPs (rs3764261 and rs12149545, rs711752, and rs708272). The A-G-G-G-C and A-T-A-A-T haplotypes might be protective factors for MS.

Association of Cholesterol Ester Transfer Protein Taq IB Polymorphism With Acute Coronary Syndrome in Egyptian National Patients

Background

The association between cholesterol ester transfer protein (CETP) Taq IB polymorphism and coronary artery disease (CAD) has been studied in different populations. Acute coronary syndrome (ACS) is a group of clinical symptoms within acute myocardial ischemia, including unstable angina (UA) and myocardial infarction (MI). Because there are no data reported in the literature concerning the cholesteryl ester transfer protein (CETP) Taq IB polymorphism in Egyptians, our study aimed to investigate the frequency of different CETP Taq IB genotypes in Egyptian patients with ACS and in healthy control individuals.

Methods

The current study was conducted with 70 hospitalized patients who had been diagnosed with ACS and 30 controls. We used real-time polymerase chain reaction (RT-PCR) to determine CETP Taq IB in individuals with different genotypes.

Results

The frequency of the GA genotype was significantly lower in UA patients, compared with the control group ( P  <.05).

Conclusions

The frequency of the CETP Taq IB genotypes and alleles in all groups was similar to that in other ethnic groups. Individuals with the Taq IB GA genotype may have a lower risk of UA.

Association of the CETP gene TaqIB and D442G polymorphisms with essential hypertension in the Chinese Mongolian population

BACKGROUND/AIM

This study aimed to explore the associations of the cholesteryl ester transfer protein (CETP) gene TaqIB and D442G polymorphisms with essential hypertension (EH).

MATERIALS AND METHODS

In this case-control study, 883 hypertensive patients and 1044 normal controls were randomly selected from the Mongolian population of China. Polymerase chain reaction (PCR) and direct sequencing of PCR products were used to identify the genotypes. Haplotype analysis was performed by estimating the haplotype frequencies using the online SHEsis package.

RESULTS

The distribution frequency of the B2-G haplotype was significantly lower in the EH group than in the control group (0.7% vs. 1.9%, P = 0.001, OR = 0.359 [0.188-0.689]). Subjects with the B2B2 genotype showed significantly lower levels of total cholesterol (TC) (P < 0.05). When subgrouped by sex, male subjects with the B2B2 genotype showed significantly increased high-density lipoprotein cholesterol and decreased TC levels (P < 0.05), and those with the B2 allele showed significantly lower triglyceride levels as compared to the subjects with the B1B1 homozygote (P < 0.05).

CONCLUSION

TaqIB and D442G polymorphisms of the CETP gene did not independently affect the risk of developing EH in the Chinese Mongolian population, while the B2-G haplotype obviously decreased the susceptibility to EH. The B2 allele could alter the blood lipid level and reduce the risk of developing cardiovascular diseases.

Meta-analysis of genome-wide association studies of HDL cholesterol response to statins

BACKGROUND

In addition to lowering low density lipoprotein cholesterol (LDL-C), statin therapy also raises high density lipoprotein cholesterol (HDL-C) levels. Inter-individual variation in HDL-C response to statins may be partially explained by genetic variation.

METHODS AND RESULTS

We performed a meta-analysis of genome-wide association studies (GWAS) to identify variants with an effect on statin-induced high density lipoprotein cholesterol (HDL-C) changes. The 123 most promising signals with p<1×10-4 from the 16 769 statin-treated participants in the first analysis stage were followed up in an independent group of 10 951 statin-treated individuals, providing a total sample size of 27 720 individuals. The only associations of genome-wide significance (p<5×10-8) were between minor alleles at the CETP locus and greater HDL-C response to statin treatment.

CONCLUSIONS

Based on results from this study that included a relatively large sample size, we suggest that CETP may be the only detectable locus with common genetic variants that influence HDL-C response to statins substantially in individuals of European descent. Although CETP is known to be associated with HDL-C, we provide evidence that this pharmacogenetic effect is independent of its association with baseline HDL-C levels.

New Era of Lipid-Lowering Drugs

There are several established lipid-modifying agents, including statins, fibrates, niacin, and ezetimibe, that have been shown in randomized clinical outcome trials to reduce the risk of having an atherosclerotic cardiovascular event. However, in many people, the risk of having an event remains unacceptably high despite treatment with these established agents. This has stimulated the search for new therapies designed to reduce residual cardiovascular risk. New approaches that target atherogenic lipoproteins include: 1) inhibition of proprotein convertase subtilisin/kexin type 9 to increase removal of atherogenic lipoproteins from plasma; 2) inhibition of the synthesis of apolipoprotein (apo) B, the main protein component of atherogenic lipoproteins; 3) inhibition of microsomal triglyceride transfer protein to block the formation of atherogenic lipoproteins; 4) inhibition of adenosine triphosphate citrate lyase to inhibit the synthesis of cholesterol; 5) inhibition of the synthesis of lipoprotein(a), a factor known to cause atherosclerosis; 6) inhibition of apoC-III to reduce triglyceride-rich lipoproteins and to enhance high-density lipoprotein (HDL) functionality; and 7) inhibition of cholesteryl ester transfer protein, which not only reduces the concentration of atherogenic lipoproteins but also increases the level and function of the potentially antiatherogenic HDL fraction. Other new therapies that specifically target HDLs include infusions of reconstituted HDLs, HDL delipidation, and infusions of apoA-I mimetic peptides that mimic some of the functions of HDLs. This review describes the scientific basis and rationale for developing these new therapies and provides a brief summary of established therapies.

Pharmacogenomics of statins: understanding susceptibility to adverse effects

Statins are a cornerstone of the pharmacologic treatment and prevention of atherosclerotic cardiovascular disease. Atherosclerotic disease is a predominant cause of mortality and morbidity worldwide. Statins are among the most commonly prescribed classes of medications, and their prescribing indications and target patient populations have been significantly expanded in the official guidelines recently published by the American and European expert panels. Adverse effects of statin pharmacotherapy, however, result in significant cost and morbidity and can lead to nonadherence and discontinuation of therapy. Statin-associated muscle symptoms occur in ~10% of patients on statins and constitute the most commonly reported adverse effect associated with statin pharmacotherapy. Substantial clinical and nonclinical research effort has been dedicated to determining whether genetics can provide meaningful insight regarding an individual patient’s risk of statin adverse effects. This contemporary review of the relevant clinical research on polymorphisms in several key genes that affect statin pharmacokinetics (eg, transporters and metabolizing enzymes), statin efficacy (eg, drug targets and pathways), and end-organ toxicity (eg, myopathy pathways) highlights several promising pharmacogenomic candidates. However, SLCO1B1 521C is currently the only clinically relevant pharmacogenetic test regarding statin toxicity, and its relevance is limited to simvastatin myopathy.

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.

Taq1B Polymorphism of Cholesteryl Ester Transfer Protein (CETP) and Its Effects on the Serum Lipid Levels in Metabolic Syndrome Patients

The metabolic syndrome (MetS) is one of the most important risk factors for type 2 diabetes and cardiovascular disease. This syndrome is characterized by abdominal obesity, hypertension, insulin resistance, and dyslipidemia. The plasma origin of Cholesteryl ester transfer protein (CETP) is responsible for transferring cholesterol esters from high-density lipoprotein particles to apolipoprotein B containing lipoproteins compartment. We conducted this study to investigate the association between CETP gene Taq1B (rs708272) polymorphism in the metabolic syndrome among Iranian subjects. A sample size of 200 patients diagnosed with MetS together with 200 healthy donors as control were enrolled in this study. The investigation of polymorphism was performed by the use of polymerase chain reaction and restriction fragment length polymorphism analysis. To determine the relationship between polymorphism and lipid profile, we measured lipids and CETP concentration in metabolic syndrome and control subjects. Genotype distribution and allelic frequencies of polymorphism were determined and compared in both groups. Our findings showed that all clinical and biochemical characteristics in patients differed from the control group. The results showed that genotype and allele frequency of the Taq1B polymorphism was not significantly different between two groups. Instinctively, CETP was significantly higher in metabolic syndrome (1.64 ± 0.32 µg/ml) than in control (1.53 ± 0.34 µg/ml). A low level of CETP was found in blood of B2B2 typified genotype. In spite of Taq1B polymorphism on ester transfer protein concentration, no direct correlation was found between this polymorphism and metabolic syndrome.

Serum CETP and PLTP activity in middle-aged men living in urban or rural area of the Lower Silesia region. PURE Poland sub-study

INTRODUCTION

The dependence of lipid transfer proteins on significant pro-atherogenic factors is unclear. The aim of the study was to evaluate serum cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activity in relation to lipid disturbances in men living in an urban or rural area.

MATERIAL AND METHODS

A group of 427 men, volunteers for the Prospective Urban Rural Epidemiology (PURE) sub-study - 263 urban inhabitants (aged 51.9 ±6.0) and 164 residents of villages (aged 51.1 ±5.9) - were examined. In the multivariable linear regression model, the following factors were included as potential confounders: age, body mass index (BMI), smoking, alcohol consumption, hs-C-reactive protein reaction (hs-CRP) and co-existence of chronic diseases.

RESULTS

In multiple linear regression models, site of residence (urban or rural area) was the most important independent and consistent predictor of CETP and PLTP activity; β coefficients (95% CI) for CETP (0.18) and PLTP (-0.29) were significant at levels of p < 0.001. Three-way analysis of variance showed no effect of smoking or moderate alcohol consumption on lipid transfer proteins; however, CETP activity showed an interaction effect between these risk factors. In the group of all men, CETP activity was significantly and positively correlated with total cholesterol (r = 0.24), low-density lipoprotein cholesterol (r = 0.18), and non-high density lipoprotein cholesterol (r = 0.21), whereas PLTP activity was correlated with BMI (r = 0.12). Body mass index in rural men was higher than in the urban male population.

CONCLUSIONS

Increased PLTP activity, recognized as a pro-atherogenic factor, and decreased CETP activity, known as a protective factor, both observed in men living in rural areas, are probably conditioned by nutritional and/or genetic factors.

Cholesteryl ester transfer protein gene polymorphism (I405V) and premature coronary artery disease in an Iranian population

The effect of human cholesteryl ester transfer protein (CETP) expression on atherogenesis is still under debate. The rs5882 (I405V) polymorphism affect CETP function. We aimed to examine the relationship between the rs5882 polymorphism and the risk of angiographically determined coronary artery disease (CAD). To define premature CAD (PCAD), an age cutoff of 55 years for women and 45 years for men was used. An age- and sex-matched case-control study was conducted in 560 patients with newly diagnosed angiographically documented PCAD (≥50% luminal stenosis of any coronary vessel) and an equal number of control patients with normal coronary arteries (no luminal stenosis at coronary arteries). The severity of CAD was determined by vessel score and Gensini score. A real-time polymerase chain reaction (PCR) and high resolution melting analysis were used to distinguish between genotypes. The I405V genotype distributions were not statistically different in CAD and non-CAD groups in univariate and multivariable-adjusted logistic regression analyzes. The median and inter-quartile range for Gensini score was not significantly different among the AA (43, 24 to 73), AG (40, 20 to 66), and GG (45, 25 to 72) genotypes (p = 0.097). Furthermore, the distribution of vessel score did not statistically differ between these genotypes (p = 0.691). Our results suggest that there is no significant association between CETP I405V polymorphism and the risk of PCAD presence and severity. Larger prospective studies are needed to investigate such associations in different populations.

Seventeen years of statin pharmacogenetics: a systematic review

AIM

We evaluated the evidence of pharmacogenetic associations with statins in a systematic review.

METHODS

Two separate outcomes were considered of interest: modification of low-density lipoprotein cholesterol (LDL-C) response and modification of risk for cardiovascular events.

RESULTS

In candidate gene studies, 141 loci were claimed to be associated with LDL-C response. Only 5% of these associations were positively replicated. In addition, six genome-wide association studies of LDL-C response identified common SNPs in APOE, LPA, SLCO1B1, SORT1 and ABCG2 at genome-wide significance. None of the investigated SNPs consistently affected the risk reduction for cardiovascular events.

CONCLUSION

Only five genetic loci were consistently associated with LDL-C response. However, as effect sizes are modest, there is no evidence for the value of genetic testing in clinical practice.

Fine mapping the CETP region reveals a common intronic insertion associated to HDL-C

BACKGROUND

Individuals with exceptional longevity and their offspring have significantly larger high-density lipoprotein concentrations (HDL-C) particle sizes due to the increased homozygosity for the I405V variant in the cholesteryl ester transfer protein (CETP) gene. In this study, we investigate the association of CETP and HDL-C further to identify novel, independent CETP variants associated with HDL-C in humans.

METHODS

We performed a meta-analysis of HDL-C within the CETP region using 59,432 individuals imputed with 1000 Genomes data. We performed replication in an independent sample of 47,866 individuals and validation was done by Sanger sequencing.

RESULTS

The meta-analysis of HDL-C within the CETP region identified five independent variants, including an exonic variant and a common intronic insertion. We replicated these 5 variants significantly in an independent sample of 47,866 individuals. Sanger sequencing of the insertion within a single family confirmed segregation of this variant. The strongest reported association between HDL-C and CETP variants, was rs3764261; however, after conditioning on the five novel variants we identified the support for rs3764261 was highly reduced (β_unadjusted=3.179 mg/dl (P value=5.25×10^-509), β_adjusted=0.859 mg/dl (P value=9.51×10^-25)), and this finding suggests that these five novel variants may partly explain the association of CETP with HDL-C. Indeed, three of the five novel variants (rs34065661, rs5817082, rs7499892) are independent of rs3764261.

CONCLUSIONS

The causal variants in CETP that account for the association with HDL-C remain unknown. We used studies imputed to the 1000 Genomes reference panel for fine mapping of the CETP region. We identified and validated five variants within this region that may partly account for the association of the known variant (rs3764261), as well as other sources of genetic contribution to HDL-C.

Dysfunctional High-Density Lipoprotein: An Innovative Target for Proteomics and Lipidomics

High-Density Lipoprotein-Cholesterol (HDL-C) is regarded as an important protective factor against cardiovascular disease, with abundant evidence of an inverse relationship between its serum levels and risk of cardiovascular disease, as well as various antiatherogenic, antioxidant, and anti-inflammatory properties. Nevertheless, observations of hereditary syndromes featuring scant HDL-C concentration in absence of premature atherosclerotic disease suggest HDL-C levels may not be the best predictor of cardiovascular disease. Indeed, the beneficial effects of HDL may not depend solely on their concentration, but also on their quality. Distinct subfractions of this lipoprotein appear to be constituted by specific protein-lipid conglomerates necessary for different physiologic and pathophysiologic functions. However, in a chronic inflammatory microenvironment, diverse components of the HDL proteome and lipid core suffer alterations, which propel a shift towards a dysfunctional state, where HDL-C becomes proatherogenic, prooxidant, and proinflammatory. This heterogeneity highlights the need for further specialized molecular studies in this aspect, in order to achieve a better understanding of this dysfunctional state; with an emphasis on the potential role for proteomics and lipidomics as valuable methods in the search of novel therapeutic approaches for cardiovascular disease.

Regulation of cholesteryl ester transfer protein expression by upstream polymorphisms: reduced expression associated with rs247616

BACKGROUND

Cholesteryl ester transfer protein (CETP) is involved in reverse cholesterol transport by exchanging cholesteryl esters for triglycerides between high-density lipoprotein and low-density lipoprotein particles, effectively decreasing high-density lipoprotein cholesterol levels. Variants within a large haplotype block upstream of CETP (rs247616, rs173539) have been shown to be significantly associated with reduced expression; however, the underlying mechanism has not been identified.

METHODS

We analyzed the linkage structure of our top candidate single-nucleotide polymorphism (SNP), rs247616, and assessed each SNP of the haplotype block for potential interactions with transcription factor binding sites. We then used a reporter gene assay to assess the effect of three SNPs (rs247616, rs173539, and rs1723150) on expression in vitro.

RESULTS

Several variants in the upstream haplotype, including rs247616, rs173539, and rs1723150, disrupt or generate transcription factor binding sites. In reporter gene assays, rs247616 and rs173539 were found to significantly affected expression in HepG2 cells, whereas rs17231506 had no effect. rs247616 decreased expression by 1.7-fold (P<0.0001), whereas rs173539 increased expression by 2.2-fold (P=0.0006).

CONCLUSION

SNPs rs247616 and rs173539 are in high linkage disequilibrium (R=0.96, D'=1.00) and have the potential to regulate CETP expression. Although opposing effects suggest that regulation of CETP expression could vary between tissues, the minor allele of rs247616 and SNPs in high linkage with it were found to be associated with reduced expression across all tissues.

Lack of Atorvastatin Protective Effect Against Atrial Fibrillation in CETP TaqIB2B2 Genotype

There has been some evidence for a role of statins in reducing the risk of atrial fibrillation, but the response to statin treatment varies considerably due to environmental and genetic factors. One of these is related to CETP expression. So we assessed whether CETP TaqIB polymorphism influences atrial fibrillation occurrence after treatment with statins. 200 unrelated dyslipidemic Caucasian patients (146 men and 54 women; mean age 75±8) from Salento (Southern Italy), assigned to atorvastatin treatment, and 158 normolipidemic subjects (119 men and 39 women; mean age 75±11), selected from the same ward, were enrolled. All patients were followed at six-month intervals. CETP TaqIB polymorphism was genotyped by RFLP-PCR. During a mean follow-up time of 71±6 months, 64 patients (32%) of the group treated with atorvastatin and 70 subjects (44%) of the group without atorvastatin experienced at least one episode of AF, with a statistically significant difference (p = 0,0208) between the two groups. No significant differences were observed between the two groups with regard to demographic and echocardiographic data, to clinical history and pharmacological treatment. While in patients not assuming atorvastatin there was no significant difference (p = 1) between TaqIB genotype and atrial fibrillation occurence, in subjects treated with atorvastatin B2B2 genotype was more frequent in patients with atrial fibrillation (p = 0,0001). According to these data the subjects with the B2B2 genotype seem to be more susceptible to atrial fibrillation development (RR 2,74; IC 95% 1,92-3,90; p<0.025). Our data seem to provide a further evidence for the hypothesis that statins may have adverse effect in subjects with genetically low CETP levels. Because statins reduce CETP activity up to 30%, we hypothesize that such CETP activity reduction by statins, in patients with low CETP levels induced by polymorphism, may counteract the beneficial effect of statins on atrial fibrillation.

Cardiovascular drugs and the genetic response

The emergence of personalized medicine mandates a complete understating of DNA sequence variation that modulates drug response. Initial forays have been made in the cardiac arena, yet much remains to be elucidated in the pharmacogenetics of cardiac drugs. Most progress has been made in describing DNA sequence variation related to the anticoagulant warfarin and the antiplatelet drug clopidogrel. This includes a description of DNA sequence variation that underlies pharmacokinetic and pharmacodynamic variability, the impact of such variation on predicting hard outcomes, and the ability of genotype-guided prescription to facilitate rapid titration to a therapeutic range while avoiding unnecessary high plasma levels. Nuanced prescription will require a complete inventory of DNA sequence variants that underlie drug-related side effects.

A systems genetics approach to dyslipidemia in children and adolescents

Elevated triglycerides (TG) or low high density lipoprotein cholesterol (HDL-C) levels are common cardiometabolic risk factors in children. From a systems genetics standpoint, Visualization of Statistical Epistasis Networks (ViSEN) is a nonparametric entropy-based method that can characterize the global structure of interacting genetic factors. We identified a novel set of connected genetic and cardiometabolic risk factors with strong and significant interaction effects on two important dyslipidemia phenotypes (low HDL-C and high TG) in children and adolescents. Study participants were recruited from five schools in Istanbul, Turkey (n=360; 170 boys, 190 girls). Participants with TG levels≥75th and HDL-C levels≤25th percentile were defined as 'high TG' and 'low HDL-C', respectively. We genotyped participants for six single nucleotide polymorphisms (SNPs) in five genes with known associations to lipid levels (rs328 in LPL, rs708272 in CETP, rs1800588 in LIPC, rs1800977 in ABCA1, rs1799941 and rs6257 in SHBG gene). ViSEN was used to identify associations with dyslipidemia phenotypes. There were 71 (50 males, 21 females) and 93 (60 males and 33 females) subjects with low HDL-C and high TG, respectively. Biological variables including age, gender, and BMI were significantly associated with both phenotypes (p<0.001). Importantly, a single SNP, rs708272, was associated with low HDL-C (IG=2.24%, p=0.026). Pairwise and higher order interaction analyses in the full dataset for low HDL-C and high TG revealed the largest effects in the models containing rs1800977, rs708272, age (IG=6.20%, p=0.046) and rs1800588, age, BMI (IG, 3.06%, p=0.022), respectively. In conclusion, the present study brings us a step closer to a systems genetic approach in understanding lipid phenotypes in children. Further efforts can integrate population and laboratory-based studies, hence accelerate the preventive medicine efforts.

The lipoprotein lipase S447X and cholesteryl ester transfer protein rs5882 polymorphisms and their relationship with lipid profile in human serum of obese individuals

BACKGROUND

Obesity is often associated with an alter lipid profile, e.g., raised serum triglycerides (TG) and low high-density lipoprotein (HDL) cholesterol levels, both important risk factor for cardiovascular-diseases. The aim of current study was to explore the association of a polymorphism of the lipoprotein lipase (LPL) rs328 and cholesteryl-ester-transfer-protein (CETP) rs5882 genes in relation to lipid profile in subjects with/without obesity.

SUBJECTS/METHODS

Genotyping was carried out in 271 individuals, (151 obese subjects and 120 non-obese). Univariate/multivariate analyses were conducted to evaluate the association of these genetic-polymorphisms with obesity and lipid components.

RESULTS

Obese subjects had a significantly (P<0.05) higher level of triglyceride (TG), blood pressure, waist-circumference and fasting-blood-glucose, and lower level of HDL-C. LPL and CETP polymorphisms were not associated with obesity in our population. However, the LPL rs328-GG-GC genotype was significantly related to a higher concentration of TG, compared to the CC wild-type; and a higher HDL-C level in the obesity-group with respect to the control group. Moreover, obese-subjects carrying the G allele of CETP had a significantly lower level of HDL-C (P<0.05) compared to those with C allele.

CONCLUSION

We demonstrate a significant association of LPL and CETP polymorphisms with serum triglycerides and HDL-cholesterol.

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.

Pharmacogenomics of statin therapy: any new insights in efficacy or safety?

PURPOSE OF REVIEW

To examine the current evidence concerning the effects of genetic variation on statin-related low-density lipoprotein cholesterol reductions, clinical efficacy, and adverse events and the relevance for patient care.

RECENT FINDINGS

Recent years have seen the emergence of large-scale genetic experiments, including genome-wide association studies and candidate gene studies, exploring the impact of common genetic variation on patient response to statins. These studies have built on previous smaller scale evidence, providing improved statistical power and enhanced ability to explore the genome. Current evidence suggests that common genetic variants do not alter low-density lipoprotein cholesterol response by more than a few percent, or materially alter the effect of statin on vascular risk reduction, and therefore that patients benefit from statins independent of common genetic variation. However, knowledge of SLCO1B1 genotypes is believed to have clinical utility for predicting myopathy risk and ensuring that statins are prescribed as safely as possible. Furthermore, new hypothesis-generating studies, such as those associating GATM with myopathy risk, offer potential insights for the future.

SUMMARY

Common genetic variation does not appear to be an important determinant of statin response, with the exception of SLCO1B1 and risk of myopathy. Future studies will help to determine the impact of low-frequency and rare genetic variation on statin response.

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.

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.