ApoE gene polymorphism and its relationship with coronary artery disease in ethnic Kashmiri population

Genetic Polymorphisms and Genetic Risk Scores Contribute to the Risk of Coronary Artery Disease (CAD) in a North Indian Population

Coronary artery disease (CAD) is the leading cause of death in India. Many genetic polymorphisms play a role in regulating oxidative stress, blood pressure and lipid metabolism, contributing to the pathophysiology of CAD. This study examined the association between ten polymorphisms and CAD in the Jat Sikh population from Northern India, also considering polygenic risk scores. This study included 177 CAD cases and 175 healthy controls. The genetic information of GSTM1 (rs366631), GSTT1 (rs17856199), ACE (rs4646994), AGT M235T (rs699), AGT T174M (rs4762), AGTR1 A1166C (rs5186), APOA5 (rs3135506), APOC3 (rs5128), APOE (rs7412) and APOE (rs429358) and clinical information was collated. Statistical analyses were performed using SPSS version 27.0 and SNPstats. Significant independent associations were found for GST*M1, GST*T1, ACE, AGT M235T, AGT T174M, AGTR1 A1166C and APOA5 polymorphisms and CAD risk (all p < 0.05). The AGT CT haplotype was significantly associated with a higher CAD risk, even after controlling for covariates (adjusted OR = 3.93, 95% CI [2.39-6.48], p < 0.0001). The APOA5/C3 CC haplotype was also significantly associated with CAD (adjusted OR = 1.86, 95% CI [1.14-3.03], p < 0.05). A higher polygenic risk score was associated with increased CAD risk (adjusted OR = 1.98, 95% CI [1.68-2.34], p < 0.001). Seven polymorphisms were independently associated with an increase in the risk of CAD in this North Indian population. A considerable risk association of AGT, APOA5/C3 haplotypes and higher genetic risk scores is documented, which may have implications for clinical and public health applications.

Influence of apolipoprotein E gene polymorphisms on coronary artery disease in patients undergoing coronary angiography

Objective

Previous studies have shown that apolipoprotein E (ApoE) gene polymorphisms have an impact on coronary artery disease(CAD). However, many studies have small sample sizes and different conclusions. The purpose was to retrospectively study the influence of ApoE gene polymorphisms on CAD.

Methods

This study assessed the influence of different ApoE genotypes on coronary heart disease in patients who received coronary angiography and used multivariate logistic regression to assess the influence of different ApoE genotypes on CAD.

Results

Patients with different ApoE genotypes had no obvious differences in the incidence of hypertension, diabetes or obesity（P > 0.05). Patients with ε2/ε2 had higher incidence of hypertriglyceridemia than patients with other ApoE genotypes, while patients with ε3/ε3 had a lower incidence of hypertriglyceridemia than those with ε3/ε4,ε4/ε4, ε2/ε3 and ε2/ε2（P < 0.05）. Patients with ε3/ε4, ε4/ε4, ε3/ε3 and ε2/ε2 had no significant differences in the severity or incidence of CAD （P > 0.05). ε2/ε4 and ε2/ε3 reduced the risk of high LDL-C, and reduced the severity and incidence of coronary heart（P < 0.05). ε2/ε3 reduced risk of premature coronary artery disease（PCAD）（P < 0.05). ε2/ε3 reduced risk of CAD in patients age <45,age at 60-74 and age ≥74, while ε2/ε4 reduced risk of CAD in patients age ≥74（P < 0.05).

Conclusion

Patients with ε3/ε4, ε4/ε4,ε3/ε3 and ε2/ε2 had no significant differences in the severity and occurrence of CAD. Compared to the isoform ε3 (ε3/ε3), isoform ε4 did not increased the severity and occurrence of CAD. Compared with ApoE other genotypes, ε2/ε3 and ε2/ε4 reduced the risk of high LDL-C and the severity and occurrence of CAD.

Sex-specific differences in the association between APOE genotype and metabolic syndrome among middle-aged and older rural Indians

Background

Metabolic syndrome (MetS), characterized by elevated blood pressure, high blood glucose, excess abdominal fat, and abnormal cholesterol or triglyceride levels, significantly increases the risk of various non-communicable diseases. This study focuses on understanding the sex-specific association between Apolipoprotein E (APOE) polymorphism and MetS among middle-aged and older adults in rural southern India.

Methods

This cross-sectional study utilized data from the Centre for Brain Research-Srinivaspura Aging, Neuro Senescence, and COGnition (CBR-SANSCOG) study. Participants (n = 3741) underwent comprehensive clinical assessments and blood investigations, including APOE genotyping. MetS was defined using the National Cholesterol Education Program - Adult Treatment Panel III (NCEP ATP III) and the Consensus criteria. Statistical analyses, including chi-square tests, ANCOVA, and logistic regression, were conducted to explore the association of APOE genotype with MetS and its components, stratified by sex.

Results

Females carrying the APOE E4 allele had 1.31-fold increased odds of MetS (95 % CI: 1.02,1.69, p = 0.035) according to the NCEP ATP III criteria but not when the Consensus criteria were applied. The study also noted sex-specific differences in the association of APOE with various MetS components, including lipid levels and waist circumference.

Discussion

Our findings reveal a sex-specific association between the APOE E4 allele and MetS, with only females having an increased risk. This study contributes to the understanding of the genetic underpinnings of MetS and highlights the importance of considering sex-specific differences in MetS research and its prevention strategies. This study underscores the complexity of MetS etiology and emphasizes the need for further research to elucidate the role of genetic, environmental, and lifestyle factors in its progression, particularly in sex-specific contexts.

Lipid-Related Genetic Variants for Personalized Dietary Interventions: A Systematic Review

Dyslipidemias are known risk factors for chronic diseases. Precision nutrition interventions are designed according to characteristics, such as diet, phenotype, and genotype. This systematic review aims to define a panel of genetic variants associated with lipid abnormalities that could be later used in nutrigenetic intervention studies. A systematic review is conducted following the PRISMA-P. Studies published from January 2010 to December 2020 in English language and humans are included from PubMed and ScienceDirect databases. Articles that demonstrate a strong association between polymorphisms (single nucleotide variation) of genes involved in lipid metabolism and increased risk for dyslipidemia are included. A total of 3031 articles are screened, but only 51 articles fulfill the inclusion criteria. The genes included are FABP2, MTTP related to CM synthesis and secretion; LPL, LIPC involved in triglyceride hydrolysis; CETP, APOA1, LCAT, ABCA1, and APOA5 related to lipoprotein metabolism, and APOE, LDLR, SCARB1, APOC3 involved in lipid clearance. In this systematic review, genetic variants related to chylomicron synthesis, triglyceride hydrolysis, lipoprotein metabolism, and lipid clearance demonstrate a strong association with lipid abnormalities, which can be used to design precision nutrition interventions that may help to prevent and treat dyslipidemia effectively.

Utilizing apolipoprotein E genotypes and associated comorbidities for the assessment of the risk for dementia

Introduction

Dementia is associated with many comorbidities while being related to Apolipoprotein E (ApoE) polymorphism. However, it is unclear how these clinical illnesses and genetic factors modify the dementia risk.

Methods

We enrolled 600 dementia cases and 6000 matched non-dementia controls, with identified ApoE genotype (ε4/ε4, ε4/ε3, and ε3/ε3). Eight comorbidities were selected by medical records, and counted if occurring within 3 years of enrollment.

Results

The dementia group had a higher ratio of carrying ε4 allele and prevalence of comorbidities than the non-dementia group. Homozygous ε4 carriers presented the broken line of dementia risk with the peak age at 65-75 years and odds ratio (OR) up to 6.6. The risk only emerged after 65 years of age in ε3/ε4 subjects with OR around 1.6-2.4 when aged > 75 years. Cerebrovascular accident (CVA) is the commonest comorbidity (14.6%). CVA, sleep disorder, and functional gastrointestinal disorders remained as significant risk comorbidities for dementia throughout all age groups (OR = 1.7-5.0). When functional gastrointestinal disorder and ε4 allele both occurred, the dementia risk exceeded the summation of individual risks (OR = 3.7 and 1.9 individually, OR = 6.0 for the combination). Comorbidities could also be predictors of dementia.

Conclusion

Combining the genetic and clinical information, we detected cognitive decline and optimize interventions early when the patients present a specific illness in a particular age and carry a specific ApoE allele. Of comorbidities, functional gastrointestinal disorder is the strongest predicting factor for dementia in ε4 allele carriers.

An integrated framework for local genetic correlation analysis

Genetic correlation (r_g) analysis is used to identify phenotypes that may have a shared genetic basis. Traditionally, r_g is studied globally, considering only the average of the shared signal across the genome, although this approach may fail when the r_g is confined to particular genomic regions or in opposing directions at different loci. Current tools for local r_g analysis are restricted to analysis of two phenotypes. Here we introduce LAVA, an integrated framework for local r_g analysis that, in addition to testing the standard bivariate local r_gs between two phenotypes, can evaluate local heritabilities and analyze conditional genetic relations between several phenotypes using partial correlation and multiple regression. Applied to 25 behavioral and health phenotypes, we show considerable heterogeneity in the bivariate local r_gs across the genome, which is often masked by the global r_g patterns, and demonstrate how our conditional approaches can elucidate more complex, multivariate genetic relations.

Dissecting the Association of Apolipoprotein E Gene Polymorphisms With Type 2 Diabetes Mellitus and Coronary Artery Disease

BACKGROUND

Apolipoprotein E (APOE) gene mediates lipoprotein clearance and is one of the most studied candidate genes for type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD). This study was performed to determine the association between APOE polymorphisms and T2DM with and without CAD, and its effect on plasma lipid levels in a Chinese population.

METHODS

A total of 1,414 subjects involving 869 patients and 545 health individuals were recruited. These patients were categorized into three distinct groups: 264 in T2DM group, 401 in CAD group, and 204 in T2DM+CAD group. Logistic regression analysis was used to obtain odds ratio (OR) and 95% confidence interval (CI) in predicting the risk probability of APOE. Besides, a meta-analysis was preformed to integrate an evaluation index to evaluate their associations.

RESULTS

Genotype frequency ratio of genotype ϵ3/4 and allele ϵ4 among the CAD patients with or without T2DM was obviously increased. Compared with ϵ3/3 genotype, the ϵ3/4 genotype had a significant increased risk of CAD (adjusted OR = 1.90, 95% CI = 1.30-2.77) and T2DM+CAD (adjusted OR = 1.95, 95% CI = 1.24-3.08). In the meta-analysis, four studies were included and provided a strong evidence for the APOE ϵ4 mutation elevating the risk of CAD in patients with T2DM (ϵ3/ϵ4+ϵ4/ϵ4 vs. ϵ3/ϵ3, OR = 1.51, 95% CI = 1.13-2.02). In the T2DM group, the plasma levels of low-density lipoprotein cholesterol (LDL-C) showed significant difference among the three APOE isoforms. The high-density lipoprotein cholesterol (HDL-C) levels of CAD patients with ϵ4-bearing genotypes were lower than those with ϵ3/3 genotype.

CONCLUSIONS

Our results indicate that APOE gene polymorphisms are related to CAD with or without T2DM and have influence on lipid profiles in both T2DM and CAD patients.

The association of apolipoprotein-E (APOE) gene polymorphisms with coronary artery disease: a systematic review and meta-analysis

Background

Numerous studies have investigated the role of apolipoprotein E (APOE) polymorphisms in coronary artery disease (CAD), but some controversies exist regarding the outcomes as the results were not consistent and remain uncertain. Therefore, the present meta-analysis was conducted to evaluate the association of APOE polymorphisms with coronary artery disease.

Methods

All the relevant studies published in English language till August 2020 were identified by searching through various electronic databases. The complete data was independently extracted by the two researchers. The data were analyzed by using the Comprehensive Meta-Analysis program and MetaGenyo program. The pooled odds ratio was used to check the associations between CAD and APOE polymorphisms. The following genetic models were used to calculate the odds ratio: ε2 vs. ε3 and ε4 vs. ε3.

Results

In the final analysis, we include 12 studies regarding the role of APOE polymorphism in CAD. The pooled odds ratio for ε4 allele was higher (OR 2.00; 95% and CI, 1.48–2.71). There is no statistical significant association for ε2 allele with CAD (OR 1.38; 95% CI, 1.18–1.62). This analysis showed no publication bias exists in the current meta-analysis.

Conclusions

Our findings suggest that the apolipoprotein ε4 allele appears as a significant genetic risk factor for coronary artery disease while the ε2 allele is beneficial to alleviate the CAD risk.

Trial registration

Registered with PROSPERO International Prospective Register of Systematic Reviews. PROSPERO registration number CRD42020190464

APOE Gene Associated with Cholesterol-Related Traits in the Hispanic Population

Genetic variants in the apolipoprotein E (APOE) gene are associated with lipid metabolism and lipid-related traits in the non-Hispanic population. There have been limited studies regarding the association between the APOE gene and hypercholesterolemia in the Hispanic population; therefore, our aim for this study is to examine the APOE gene’s associations with cholesterol level and its related phenotypes. The APOE gene consists of three different alleles, ε2, ε3, and ε4, with ε4 being associated with dementia and cardiovascular diseases. A total of 1,382 subjects were collected from the Texas Alzheimer’s Research and Care Consortium (TARCC, N = 1320) and the Initial Study of Longevity and Dementia from the Rio Grande Valley (ISLD-RGV, N = 62). Questionnaires on demographics, medical history, and blood/saliva samples were collected and APOE genotypes were performed. We observed allele frequencies of the APOE ε3 (96.7%), ε4 (22.6%) and ε2 (6.8%) alleles, respectively. Multivariable logistic regression revealed a significant association between the APOE ε4 allele and hypercholesteremia (p = 1.8 × 10⁻⁴) in our studied Hispanic population. We prove for the first time, that the APOE ε4 allele increases the risk for hypercholesterol in Hispanics. Further research is needed to confirm and supports our current findings.

Features of Lipid Metabolism in Humanized ApoE Knockin Rat Models

Apolipoprotein E (ApoE), an essential plasma apolipoprotein, has three isoforms (E2, E3, and E4) in humans. E2 is associated with type III hyperlipoproteinemia. E4 is the major susceptibility gene to Alzheimer’s disease (AD) and coronary heart disease (CHD). We investigated lipid metabolism and atherosclerotic lesions of novel humanized ApoE knockin (hApoE KI) rats in comparison to wide-type (WT) and ApoE knockout (ApoE KO) rats. The hApoE2 rats showed the lowest bodyweight and white fat mass. hApoE2 rats developed higher serum total cholesterol (TC), total triglyceride (TG), and low- and very low density lipoprotein (LDL-C&VLDL-C). ApoE KO rats also exhibited elevated TC and LDL-C&VLDL-C. Only mild atherosclerotic lesions were detected in hApoE2 and ApoE KO aortic roots. Half of the hApoE2 rats developed hepatic nodular cirrhosis. A short period of the Paigen diet (PD) treatment led to the premature death of the hApoE2 and ApoE KO rats. Severe vascular wall thickening of the coronary and pulmonary arteries was observed in 4-month PD-treated hApoE4 rats. In conclusion, hApoE2 rats develop spontaneous hyperlipidemia and might be suitable for studies of lipid metabolism-related diseases. With the PD challenge, hApoE4 KI rats could be a novel model for the analysis of vascular remodeling.

Association of APOE genotype with lipid profiles and type 2 diabetes mellitus in a Korean population

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with chronic hyperglycemia and lipid metabolism. A previous genome-wide association study revealed the TOMM40-APOE region as novel locus for T2DM susceptibility.

OBJECTIVE

This association study was conducted to determine the genetic effects of APOE single nucleotide polymorphisms (SNPs) on T2DM susceptibility and lipid profiles in a Korean population.

METHODS

A total of 6 tagging SNPs, including rs7412 and rs429358, were selected for ε genotype analysis and genotyped in 1436 subjects, consisting of 352 T2DM patients and 1084 unaffected controls.

RESULTS

Logistic regression analyses were conducted and there were no significant associations among the APOE 6 tagging SNPs, ε genotypes, and haplotypes with T2DM susceptibility. To investigate the association of the APOE tagging SNPs with the lipid profiles, a regression analysis was conducted. As a result, rs7412 was significantly associated with the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) levels (P_corr = 2.30 × 10^-5 and 3.39 × 10^-13, respectively) in the unaffected controls. The ε2 allele and ε3 allele were significantly associated with the TC (P_corr = 4.46 × 10^-6 and 0.02, respectively) and LDL levels (P_corr = 3.54 × 10^-14 and 0.0006, respectively) in the unaffected controls. Further analysis of only the unaffected controls was conducted. As a result, the APOE alleles ε2 and ε3 showed a significant association with the TC and LDL levels (P < 0.05).

CONCLUSION

The results of this study may help in understanding APOE polymorphisms and ε alleles and lipid profiles, which have been highly linked to T2DM, in a Korean population.

Case Report: Hypertriglyceridemia and Premature Atherosclerosis in a Patient With Apolipoprotein E Gene ε2ε1 Genotype

We present a case of a 40-year-old male with premature atherosclerosis, with evidence of both eruptive and tendinous xanthomas, which could imply an increase in both low-density lipoprotein (LDL) and triglyceride (TG) levels. However, his LDL was 2.08 mmol/l, TG -11.8 mmol/l on rosuvastatin 20 mg. Genetic evaluation was performed using a custom panel consisting of 25 genes and 280 variants responsible for lipid metabolism. A rare ε2ε1 genotype of apolipoprotein E was detected. The combination of clinical manifestations and genetic factors in this patient leads to the diagnosis of familial dysbetalipoproteinemia. Implementation of genetic testing into routine clinical practice could not only improve disease diagnostics and management, but also help prevent their development.

Presence of the apolipoprotein E-ε4 allele is associated with an increased risk of sepsis progression

Growing evidence indicated that single nucleotide polymorphisms (SNPs) in the apolipoprotein E (APOE) gene are related to increase the risk of many inflammatory-related diseases. However, few genetic studies have associated the APOE gene polymorphism with sepsis. This study was to investigate the clinical relevance of the APOE gene polymorphism in the onset and progression of sepsis. A multicenter case–control association study with a large sample size (601 septic patients and 699 healthy individuals) was conducted. Clinical data showed that the APOEε4 allele was overrepresented among all patients with septic shock (p = 0.031) compared with sepsis subtype, suggesting that APOEε4 allele may associated with increased susceptibility to the progression of sepsis. Moreover, the APOE mRNA levels decreased after lipopolysaccharide (LPS) stimulation in cells in culture. Then 21 healthy individuals to extract PBMC for genotype grouping (APOE4+ group 8; APOE4− group 13) was selected to evaluate the effect on APOE level, and results showed that the expression level of APOE in APOE4+ group and APOE4− group did not differ in mRNA levels after an LPS challenge, but the protein levels in APOE4+ group decreased slower than that in APOE4− group, and this process was accompanied by the upregulation of proinflammatory cytokines. These results provide evidence that the APOEε4 allele might be associated with the development of sepsis and a potential risk factor that can be used in the prognosis of sepsis.

Application of Genome-Wide Association Studies in Coronary Artery Disease

Coronary artery disease (CAD) is a complex disease caused by the combination of environmental and genetic factors. It is one of the leading causes of death and disability in the world. Much research has been focussed on CAD genetic mechanism. In recent years, genome-wide association study (GWAS) has developed rapidly around the world. Medical researchers around the world have successfully discovered a series of CAD genetic susceptibility genes or susceptible loci using medical research strategies, leading CAD research toward a new stage. This paper briefly summarizes the important progress made by GWAS for CAD in the world in recent years, and then analyzes the challenges faced by GWAS at this stage and the development trend of future research, to promote the transformation of genetic research results into clinical practice and provide guidance for further exploration of the genetic mechanism of CAD.

Association between apolipoprotein E gene polymorphism and the risk of coronary artery disease in Hakka postmenopausal women in southern China

Background

Apolipoprotein E (APOE) is involved in the pathogenesis of atherosclerosis and conveys a higher risk of coronary artery disease (CAD). The aim of the present study was to investigate the possible association between APOE gene polymorphism and the risk of CAD in postmenopausal Hakka women in southern China.

Methods

The APOE genotypes of 653 CAD patients and 646 control participants were determined by the polymerase chain reaction (PCR) and hybridization to a Sinochip.

Results

The prevalence of each APOE genotype differed between CAD patients and control participants (P = 0.011). The E3/E3 genotype was the most common and the E2/E2 genotype was the least common in the study sample. Moreover, the presence of ε4 allele was associated with higher serum concentrations of triglycerides (TG), total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C), and lower concentration of high-density lipoprotein-cholesterol (HDL-C). Multiple logistic regression analysis revealed that participants with ε4 allele have a significantly higher risk of CAD after adjustment for the presence of diabetes mellitus and hypertension, and their serum uric acid, TC, and LDL-C concentrations (adjusted odds ratio (OR) 1.50, 95% confidence interval (CI) 1.10–2.05, P = 0.010).

Conclusions

The present results suggest that APOE polymorphism is associated with a higher risk of CAD in postmenopausal Hakka women in southern China.

The exchangeable apolipoproteins in lipid metabolism and obesity

Dyslipidemia, characterized by increased plasma levels of low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), triglyceride (TG), and reduced plasma levels of high-density lipoprotein cholesterol (HDL-C), is confirmed as a hallmark of obesity and cardiovascular diseases (CVD), posing serious risks to the future health of humans. Thus, it is important to understand the molecular metabolism of dyslipidemia, which could help reduce the morbidity and mortality of obesity and CVD. Currently, several exchangeable apolipoproteins, such as apolipoprotein A1 (ApoA1), apolipoprotein A5 (ApoA5), apolipoprotein E (ApoE), and apolipoprotein C3 (ApoC3), have been verified to exert vital effects on modulating lipid metabolism and homeostasis both in plasma and in cells, which consequently affect dyslipidemia. In the present review, we summarize the findings of the effect of exchangeable apolipoproteins on affecting lipid metabolism in adipocytes and hepatocytes. Furthermore, we also provide new insights into the mechanisms by which the exchangeable apolipoproteins influence the pathogenesis of dyslipidemia and its related cardio-metabolic disorders.

APOE polymorphism is associated with blood lipid and serum uric acid metabolism in hypertension or coronary heart disease in a Chinese population

Aim: To explore the association of APOE polymorphism (rs7412:526C>T and rs429358:388T>C) with glucose, lipid and serum uric acid (UA) metabolism in patients with hypertension or coronary heart disease (CHD). Methods: A total of 544 patients with hypertension or CHD were selected for this study from March 2017 to January 2018. According to the APOE genotypes (excluding the E2/E4 genotype), the subjects were divided into three groups (E2/E2+E2/E3 genotypes, E3/E3 genotype [the wild-type] and E3/E4+E4/E4 genotypes) and the difference of metabolism among the three groups was compared. Results: There were significant differences in total cholesterol (TC), triglycerides, low-density lipoprotein (LDL), high-density lipoprotein and serum UA levels among the three groups. Compared with APOE E3 homozygote, APOE E4 carriers possessed higher TC, triglycerides and LDL levels, whereas APOE E2 carriers had higher high-density lipoprotein level, lower TC and LDL levels. Furthermore, multivariate logistic regression analysis found that setting E3/E3 genotype as the reference group, the carriers of APOE E4 allele (E3/E4+E4/E4 genotypes) were significantly related to hypertriglyceridemia, and APOE E2 allele (E2/E2+E2/E3 genotypes) was significantly correlated with hyperuricemia. Conclusion: APOE polymorphism was associated with blood lipid and serum UA metabolism in patients with hypertension or CHD. Compared with APOE E3 homozygote, APOE E4 allele was related to elevated triglycerides, and APOE E2 allele was correlated with increased serum UA level.

A Case-Control Study of the Association of the Polymorphisms of MTHFR and APOE with Risk Factors and the Severity of Coronary Artery Disease

OBJECTIVES

To explore the association between single-nucleotide polymorphisms (SNPs) in MTHFR and APOE and the risk of CAD and, more importantly, the severity of CAD and the profile of serum lipids, we performed a case-control study in a Chinese Han population.

METHODS

A total of 1,207 cases of consecutive CAD-suspected inpatients were recruited, and 406 CAD cases and 231 non-CAD controls were enrolled for the final analysis after screening for exclusion criteria. All subjects had undergone coronary angiography, and the severity of CAD was evaluated by 2 cardiologists according to the Gensini scores. The genotypes of MTHFR and APOEwere detected using real-time PCR, and then verified by Sanger sequencing. Environmental risk factors, such as age, sex, smoking, alcohol consumption, hypertension, diabetes, dyslipidemia, and BMI were collected. Statistical analyses (the χ2 test, binary logistic regression analysis, and ordinal polytomous logistic regression analysis) were performed with SPSS v16.0.

RESULTS

The genotypes ofall the subjects included in the CAD and non-CAD groups in this study were successfully detected, with an agreement of 100% with Sanger sequencing. The distributions of genotypes CT and TT at MTHFR C667T were higher in CAD cases than in non-CAD controls (OR 1.99, 95% CI 1.34-2.95; OR 1.77, 95% CI 1.18-2.67; p < 0.05), whereas genotype AC at MTHFR A1298Cwas lower in CAD cases (OR 0.71, 95% CI 0.50-1.02; p < 0.05). A significant association was observed in genotypes CT and TT at MTHFR C667T and the risk of CAD (OR 1.44, 95% CI 1.27-3.67; OR 1.56, 95% CI 0.88-2.78; p < 0.05). Both genotypes and alleles of APOE were comparable in the CAD cases and non-CAD controls (p > 0.05). The genotype TT at MTHFR C667T and ε4+ at APOE were more likely to be found in the CAD subgroup with a Gensini score ≥72 (p = 0.040 and p = 0.028, respectively). Meanwhile, in the patients with genotype TT,a higher level of serum Hcy was detected, while genotype ε4+ patients possessed higher levels of serum apolipoprotein E (ApoE) and low-density lipoprotein cholesterol (LDL-C) than other genotypes.

CONCLUSION

This study revealed that the SNP site of MTHFR C667Tis associatedwith the risk of CAD in this Chinese Han population. In addition, the genotypes of TT in MTHFR C667T and ε4+in APOE may increase the severity of CAD, and higher Hcy, LDL-C, and ApoE levels may be involved in this pathogenic process.

Association study between DNA methylation and genetic variation of APOE gene with the risk of coronary artery disease

Coronary artery disease (CAD) is a common health problem with a high rate of disability and death. Dyslipidemia and altered metabolism of Apo-lipoproteins are involved in the CAD pathogenesis. The current study investigated two common polymorphisms (rs429358 and rs7412) and promoter DNA methylation status of APOE in the Iranian CAD patients and control subjects. Two hundred angiographically documented CAD patients and 200 control subjects were included in the study. The APOE polymorphism analysis was done by PCR-RFLP technique and DNA methylation status was evaluated by methylation specific PCR. The assay of lipid levels was conducted using standard colorimetric protocols. Results indicated that the frequency of ε3/ε4 and ε2/ε3 genotypes was significantly more common in CAD group compared with control group. Relative to wild type genotype (ε3/ε3), CAD patients with ε3/ε4 and ε2/ε3 genotypes displayed significantly higher concentration of total-cholesterol and LDL-cholesterol. The frequency of DNA methylation of APOE was similar between the two studied groups. However, the methylation frequency of APOE gene was significantly higher in triple stenotic vessels relative to single stenotic vessels (P=0.032). In conclusion The present study indicated that the rs429358 and rs7412 polymorphisms are significantly risk factors for development and severity of CAD. Also, APOE methylation status may be involved in the severity but not in the development of CAD.

Proficiency of data interpretation: identification of signaling SNPs/specific loci for coronary artery disease

Database URLs

http://www.regulomedb.org/;https://www.broadinstitute.org/mpg/snap/.

Serum apolipoprotein E concentration and polymorphism influence serum lipid levels in Chinese Shandong Han population

Apolipoprotein E (ApoE), which has been shown to influence serum lipid parameters, can bind to multiple types of lipids and plays an important role in the metabolism and homeostasis of lipids and lipoproteins. A previous study showed that ApoE concentration significantly affects serum lipid levels independently of ApoE polymorphism. The serum lipid levels were also closely correlated with dietary habits, and Shandong cuisine is famous for its high salt and oil contents, which widely differ among the different areas in China. Therefore, studying the effect of ApoE polymorphism on ApoE concentration and serum lipid levels in Shandong province is very important.A total of 815 subjects including 285 men and 530 women were randomly selected and studied from Jinan, Shandong province. In order to evaluate the association of ApoE polymorphism and serum level on lipid profiles, the ApoE genotypes, as well as levels of fasting serum ApoE and other lipid parameters, were detected in all subjects.The frequency of the ApoE E3 allele was highest (83.1%), while those of E2 and E4 were 9.4% and 7.5%, respectively, which are similar to those in other Asian populations. ApoE2 allele carriers showed significantly increased ApoE levels but lower levels of serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and Apolipoprotein B (ApoB).We found that ApoE level is influenced by ApoE polymorphism in a gene-dependent manner. The ApoE polymorphism showed different influences on serum lipid parameters with increasing age and body mass index (BMI) in our Shandong Han population.

Apolipoprotein E Gene Variants and Risk of Coronary Heart Disease: A Meta-Analysis

Objectives. Apo E genes involved in lipoprotein synthesis and metabolism are considered one of the candidates to CHD. However, the results remain conflicting. Methods. We performed this meta-analysis based on 30 published studies including 11,804 CHD patients and 17,713 controls. Results. Compared with the wild genotype E3/3, the variant genotypes ApoEE3/4 and E4/4 were associated with 22% and 45% increased risk of CHD, respectively (E3/4 versus E3/3: OR = 1.22, 95% CI = 1.15–1.29; E4/4 versus E3/3: OR = 1.45, 95% CI = 1.23–1.71). Besides, compared with ε3 allele, carriers with the ε4 allele had a 46% increased risk of CHD (OR = 1.46, 95% CI = 1.28–1.66), while the ε2 had no significantly decreased risk of CHD. In the subgroup analysis by ethnicity, ε4 had a 25% increased risk of CHD in Caucasians (OR = 1.25, 95% CI = 1.11–1.41), and the effects were more evident in Mongolians (OR = 2.29, 95% CI = 1.89–2.77). The ε2 allele had a decreased risk of CHD in Caucasians (OR = 0.84, 95% CI = 0.74–0.96), but not in Mongolians. Conclusions. The analysis suggested that ApoEε4 mutation was associated with the increased risk of CHD, while ApoEε2 allele had a decreased risk of CHD just in Caucasians.

Apolipoprotein E gene polymorphism and risk of type 2 diabetes and cardiovascular disease

BACKGROUND

Lipoprotein-related mechanisms have been associated with damage to the cardiovascular system in diabetic patients. Apolipoprotein E gene which affects the clearance of lipoproteins and consequently the lipid profile in our body is one of the most studied candidate genes and recently has been reported to be associated with T2DM and CAD. In this work, we studied the association of apoE gene polymorphism with T2DM and CVD and its effect on plasma lipids profile.

METHODS

Our study was conducted on 284 subjects categorized into 100 patients with T2DM, 100 patients with T2DM complicated with CVD and 84 normal control subjects. ApoE gene polymorphism was genotyped by real-time PCR using TaqMan(®) SNP Genotyping Assay.

RESULTS

ApoE E3/E3 genotype was the most common in our subjects. The frequencies of E3/E4 genotype and ε4 allele were increased in both T2DM patients and CVD patients as compared with controls, but were significant only in CVD patients (p = 0.004 and 0.007, respectively). Diabetic patients who carried E3/E4 genotype were at 2.4-fold increased risk to develop CVD (95 % CI 1.14-5.19, P = 0.02) and the ε4 allele associated with 2.23-fold higher CVD risk (95 % CI 1.09-4.59, P = 0.02). After adjustment for other established risk factors, E3/E4 genotype was an independent risk factor for CVD (OR = 2.3, p = 0.009) but not for T2DM (OR = 1.7, p = 0.28), while ε4 allele was an independent risk factor for both T2DM (OR = 2.2, p = 0.04) and CVD (OR = 3.0, p = 0.018) with 5.9-fold increased risk to develop CVD in T2DM patients (p = 0.019). E3/E4 genotype associated with significantly higher levels of TC and non HDL-C in all groups and with significantly higher levels of LDL-C in both T2DM and CVD patients.

CONCLUSIONS

ApoE gene polymorphisms associate with CVD and affect the lipid profile. The ε4 allele is an independent risk factor for both T2DM and CVD. Further genetic studies to add information beyond the traditional cardiovascular risk factors in T2DM and to identify risk genotypes will help in early prediction and identification of at risk patients.