The Relationship Between Apolipoprotein E Polymorphism And Severity In Male Patients With Coronary Heart Disease

Studies on genetics showed that coronary heart disease (CHD) is a multi-factors disease. It is caused by the interaction of genetic and enviromental factors.Many risk factors contribute to CHD such as hypertension,hyperlipidemia, smoking and diabetes have been identified by epidemiology investigations. But at the same time, CHD shows an obvious trend of congregation. It infered that besides enviromental factors, genetic factors play an important role in occurrence of CHD. In a family where there is premature CHD (less than 55 years old) or there are more than one CHD patients, genetic factors play a more important role. Why different people have different response to the same enviromental risk factor? Why different people have different susceptibility to CHD? These are still unknown. Until now, etiology of CHD is also unclear. Recently, studies have shown that gene polymorphisms are related to CHD susceptibility. Exploration of genes susceptible to CHD has been a hotspot of studies on CHD etiology. There were hyperlipidemia in many CHD patients, andHyper lipidemia is one main contributive factor to CHD. ApolipoproteinE (ApoE) plays a central role in lipid metabolism. Therefore mutation in ApoE gene may be associated with CHD. In some previous studies, DNA variants of the ApoE gene are associated with changes in lipid metabolism and occurrence of CHD. Because gene polymorphisms are different with human race and geographic location, the conclusion was different from each other. There was still no last word on the relationship between LPL gene polymorphisms and hyperlipidemia and CHD.The purpose of this study was to test whether ApoE restriction fragment length polymorphisms was associated with hyperlipidemia and angiographic coronary artery disease and whether they were genetic susceptibility markers of CHD.PCR-RFLP analyzing methods were used in the study designed a case-case study. We analyzed ApoE gene polymorphic markers in 108 male patients undergoing coronary angiography. We compared ApoE allele frequency and lipid levels. We assessed coronary artery disease severity as the number of significantly stenosed (50% luminal obstruction) major coronary arteries at angiography and by the Gensini coronary score. Findings were as follows:1.There were more apolipoproteins E3/4 genotype and more E4/4 alleles frequency in male CHD patients, it pointed out that E4/4 alleles were a genetic marker predicting atherosclerosis and CHD development.2. There were an influrence on ApoE gene polymorphism to lipid levels. The HDL level of E3/3 genotype group was higher compared with E2 genotype group. And there were a significantly associated with TC TG HDL levels.3.There was a higher integral of metastasis in E4 genotype group than others, and a lower integral of metastasis in E2 genotype group than others, Multiple regression analysis showed that genotypes were significantly associated with the TC TG HDL levels and integral of metastasis. It might point out that apolipoproteinE4 genotypes were independent rick predictor for coronary artery disease severity, but apolipoproteinE2 genotypes were defend factors.In summary, there is a correlation between apolipoprotein E polymorphism influenced lipoprotein metabolism and high levels of TG / low levels of HDL-C. It is associated with not only the presence of CHD but also severity of CHD. It may be served as genetic susceptibility markers of CHD and genetic marker predicting atherosclerosis development and significantly related to the severity of coronary heart disease in male patients.