Association Between Apolipoprotein E Gene Polymorphism And The Severity Of Coronary Heart Disease In Male Patients

Objective:To evaluate the influence of apolipoprotein E(Apo E) gene polymorphism on plasma lipid levels and to explore the relationship between Apo E gene polymorphism and the severity of coronary heart disease in male patients.The discovery of sensitive genotypes contributes to providing a new evidence for CAD patients in diagnose, treatment and prognosis.Methods:205 male patients defined with CAD by CAG in the first affiliated hospital of Nanchang University were selected from August 2015 to February 2016.The average age of these patients is 61.3±8.7 years old.All of these cases were collected without liver function damage,renal impairment,thyroid disease,diabetes,familial hyperlipidemia and so on.The Apo E genotypes of the 205 male patients were determined by the Restriction Fragment Length Polymorphism(RFLP) method.Plasma lipid levels were measured by using routine methods.At the same time,personal detailed clinical variables were collected:including age,history of hypertension,smoking,and drinking,total plasma cholesterol(TC),triglyceride(TG),low density lipoproteincholesterol(LDL-C),high density lipoprotein-cholesterol(HDL-C),homocysteine(Hcy) and so on.205 male patients were firstly defined on the basis of CAG(≥50% stenosis in any major pericardial coronary artery),and recorded the number of coronary vessels with significant obstruction according to angiography. Angiographic assessment was performed using the Gensini Scoring System.All of the patients were divided into acute coronary syndrome(ACS) group and stable angina pectoris(SAP) group.We analyzed the different frequency distribution of Apo E genotypes and alleles in the above two groups, and the correlation of Apo E genotypes with ACS occurrence.Besides,we also analyzed the association between Apo E gene polymorphism and the severity of coronary heart disease.Results:1. 205 males patients were shown six kinds of genotypes(Apo E2/2,Apo E2/3, Apo E2/4,Apo E3/3,Apo E3/4 and Apo E4/4) and three kinds of alleles(ε2,ε3 and ε4).The most frequent genotypes were Apo E3/3(51.2%) and Apo E3/4(22.4%).The most frequent alleles were ε3(68.3%)and ε4(21.7%).There was no significant difference between ACS group and SAP group on the genotypes and alleles distribution(P>0.05).2. The smoking rates and Hcy level in ACS group were higher than that in SAP group(respectively 53.5% VS 38.5% P=0.043,17.6±6.3μmol/L VS 16.1±3.2μmol/L P=0.032).There was no obvious difference on these clinical variables in the above two groups,such as hypertension morbidity, smoking rate, SBP,DBP,TC,TG,LDL-C,HDL-C and alleles distribution. The logistic regression analysis revealed that Hcy is a risk factor in ACS.3.The patients with ε4 allele carriers were associated with higher LDL cholesterol and total cholesterol compared with the patients with ε3 allele carriers(4.46±0.56 VS 3.25±0.57mmol/l P<0.001).There was no significant difference on plasma triglyceride and HDL cholesterol levels between ε4 allele carriers and ε3 allele carriers.There was no statistical difference on plasma total cholesterol,triglyceride, HDL-cholesterol and LDL-cholesterol levels between ε2 allele carriers and ε3 allele carriers.The average age, hypertension morbidity,smoking rate and drinking rate appeared no obvious difference in the three groups(ε2,ε3 and ε4 allele carriers).4.The patients with ε4 allele carriers had higher multi-vascular lesion rate than ε3 allele carriers(X2=6.037 P=0.045).There was no obvious difference between ε2 allele carriers and ε3 allele carriers on multi-vascular lesion rate(X2=3.770 P=0.152).The average age and smoking rate were apparently higher in the single-vascular lesion group than that in multi-vascular lesion group(respectively 60.2±11.2y VS 62.8±6.9y p=0.01,51.3% VS 32.7% P=0.023).The blood pressure levels,plasma lipid levels,hypertension morbidity and Hcy appeared no obvious difference in the above two groups. In the multi-vascular lesion group,the logistic regression analysis revealed that age(OR=1.057,P=0.003) and smoking(OR=1.016,P=0.025) were predictor. No significant evidence showed that ε4 allele was associated with multi-vascular lesion.5.The patients with ε4 allele carriers were associated with high Gensini score compared with the patients with ε3 allele carriers(45.04±26.69 VS 42.73±27.12) and ε2 allele carriers(45.04±26.69 VS 32.96±15.01). But,there was no statistical significant difference between ε4 allele carriers and severity of CAD by using the Gensini Score,compared to the patients without ε4 allele.Conclusion:1. The frequency of Apo E3/4 and Apo E4/4 genotypes in male patients with CAD were higher than that in healthy people,from which we can infer that ε4 allele was a genetic risk factor for CAD occurrence.2. Apo E polymorphism influenced serum lipid levels and was an independent risk determinant of arteriosclerosis. The Apo E4 carriers were associated with higher LDL cholesterol and total cholesterol compared with Apo E3 carriers.3. There was no significant evidence showed that ε4 allele was associated with ACS occurrence, compared to ε2 or ε3 alleles.4. There was no significant evidence showed that ε4 allele was associated with multi-vascular lesion. Age and smoking were risk factors in multi-vascular lesion.5. There were no statistical significant difference between Apo E genotypes and severity of CAD by using the Gensini Score.