Relation between apoE gene polymorphism and Coronary Artery Disease in South East and East Asian countries

Abstract

Background and Objective: Apolipoprotein E (apoE) is a polymorphic protein with vital antioxidant and anti-atherosclerotic effects. Three apoE isoforms exist due to polymorphisms in its gene causing disturbances of lipoproteins metabolism and probability to develop cardiovascular diseases. The aim of this study was to assess the association between apoE gene polymorphism and Coronary Artery Disease (CAD) in a Malaysian population sample. Also, to integrate the study findings with other studies to increase the power of the study sample and to make a better understanding about the association between apoE gene polymorphism and CAD in Southeast and East Asian countries. Methodology: The study involved 185 patients with CAD attending HTAA hospital Kuantan, Pahang with 188 unrelated healthy control participants. The apoE gene polymorphism was determined in the participants using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) assay and was validated using direct nucleotide sequencing. The SPSS software version 19 and Chi-squared test was used for determination of allele and genotypes association with CAD. Binary logistic regression analysis of apoE genotypes, gender, ethnicity, age, blood pressure and lipid profile was used to predict the probability of developing CAD. Also, a meta-analysis was conducted using Review Manager (Version 5.3.). Results: The preliminary data has shown a non-significant association between apoE genotypes or alleles and CAD. Nevertheless, binary logistic regression analysis has shown that E3E4 genotype, high blood pressure, male gender and old age are dependent risk factors that significantly predict the occurrence of CAD in the population sample (p<0.01). The meta-analysis of studies in Southeast Asia and East Asia region had shown that carriers of the E4 allele are significantly at higher risk to develop CAD [p<0.0001, OR = 1.51 (1.24, 1.83) CI = 95%, I2 = 68%]. Conclusion: This study provides an evidence of increased risk to develop CAD among carriers of E4 allele especially if accompanied by high blood pressure, old age with the male gender.