Objective: To study the association of apolipoprotein E (APOE ) gene polymorphism with ischemic stroke (IS) in coronary heart disease (CHD) patients treated with medium-intensity statins.
Methods: The retrospective study was performed on 662 samples including 169 CHD subjects complicated with IS, 296 subjects with CHD, and 197 control subjects. The APOE  gene was obtained from case files. Univariable and multivariable logistic regression analyses were utilized to recognize the possible risks of CHD and IS.
Results: The frequency of ϵ3-ϵ4 genotype was increased in the CHD group (p =0.013) and CHD-IS group (p =0.001), the frequency of ϵ4 allele was also increased in the CHD group (p =0.047) and the CHD-IS group (p =0.009) compared with control group. ϵ3-ϵ4 genotype was the independent risk for CHD and CHD-IS after adjusting for traditional risk factors with adjusted odds ratio (AOR) 2.210, 95%CI: 1.263– 3.867, p =0.005) and (AOR 2.794, 95%CI: 1.539– 5.072, p =0.002). The ϵ4 allele was also significantly associated with CHD (AOR 2.126, 95%CI: 1.265– 3.575,=0.004) and CHD-IS (AOR 2.740, 95%CI: 1.569– 4.784, p =0.001).
Conclusion: These results demonstrated that ϵ4 allele influenced the development of CHD with or without IS, especially for the genotype of ϵ3-ϵ4. CHD patients carrying the ϵ3-ϵ4 genotype and the ϵ4 allele were significantly associated with the incidence of IS, even if medium-intensity statins had been used.
Keywords: apolipoprotein E , polymorphism, coronary heart disease, ischemic stroke, statins