Relationship Between Plasma Oxidized Low Density Lipoprotein And Residual Cholesterol In Patients With Coronary Heart Disease

Objective: Oxidized low-density lipoprotein(Ox-LDL)and residual cholesterol(RC)derived from lipids both play a vital role in the formation of coronary atherosclerosis plaques,and are closely related to the occurrence and development of coronary heart disease.In this study,RC and Ox-LDL were detected and calculated to explore the relationship between Ox-LDL and RC and its value in predicting the diagnosis and prognosis of CHD.Methods: A total of 255 patients who were hospitalized in the Cardiology Department of Lanzhou University First Hospital from September 2015 to April 2016 due to suspected coronary heart disease and met the inclusion criteria were divided into coronary heart disease group(n=126)and control group(N=129).All patients in the group completed coronary angiography.Collect the clinical data of the patients,calculate the RC according to the formula;use the enzyme-linked immunosorbent assay to detect the plasma Ox-LDL concentration.Compare the clinical data of the two groups of patients,analyze the relationship between Ox-LDL and RC and other related indicators,determine the risk factors that affect CHD in the blood lipid indicators,and use the ROC curve to analyze the ability of related blood lipid indicators to assist in the diagnosis of CHD.The patients with coronary heart disease were followed up for 4 years,and they were divided into survival group and death group.The differences in Ox-LDL and RC between the two groups were analyzed.Then the ROC curve was used to evaluate the predictive value of Ox-LDL and RC in the death of patients with coronary heart disease.Draw a survival curve to analyze the survival of indicators with predictive value.Results: 1.The proportion of men in the coronary heart disease group is relatively high,the number of smokers is large,the prevalence of diabetes and hypertension is high,and NT-pro BNP,fasting blood glucose,uric acid,homocysteine,WBC,RC,Ox-LDL The levels of LDL-C,TC,N-HDL-C and TG were significantly higher than those of the control group,and the levels of HDL-C and LVEF were significantly lower than those of the control group,and the difference was statistically significant(P<0.05).2.Ox-LDL and RC have a positive correlation(r=0.433,P<0.001);Ox-LDL is also related to TC(r=0.410,P<0.001),TG(r=0.280,P<0.001),LDL-C(r=0.309,P<0.001),N-HDL-C(r=0.371,P<0.001),fasting blood glucose(r=0.201,P=0.001),white blood cell count(r=0.209,P=0.001)and The number of smokers(r=0.157,P=0.012)was positively correlated with HDL-C(r=-0.034,P<0.593).RC and TC(r=0.438,P<0.001),TG(r=0.595,P<0.001),LDL-C(r=0.139,P=0.027),N-HDL-C(r=0.459,P<0.001)),white blood cell count(r=0.152,P=0.015)and fasting blood glucose(r=0.216,P=0.001)were positively correlated,and were negatively correlated with HDL-C(r=-0.165,P=0.008).3.RC(OR=3.448,95%CI=1.644-7.229,P=0.001),Ox-LDL(OR=1.003,95%CI=1.002-1.005,P<0.001),TG(OR=1.399,95% CI=1.095-1.787,P=0.007),HDL-C(OR=0.301,95%CI=0.126-0.717,P=0.301),LDL-C(OR=1.585,95%CI=1.145-2.193,P= 0.005),N-HDL-C(OR=1.441,95%CI=1.098-1.891,P=0.008)independent risk factors for CHD;4.The ROC curve was used to evaluate the diagnostic value of these indicators for patients with coronary heart disease.The results found that Ox-LDL(AUC=0.712,95%CI: 0.650,0.774),RC(AUC=0.638,95%CI: 0.570,0.706),LDL-C(AUC=0.583,95%CI: 0.513,0.653),TG(AUC=0.617,95%CI: 0.549,0.686),HDL-C(AUC=0.596,95%CI: 0.527,0.666)and N-HDL-C(AUC=0.583,95%CI: 0.512,0.653)has a certain diagnostic value for patients with coronary heart disease(all P<0.05),of which the diagnostic value of Ox-LDL is the greatest,when the cutoff of Ox-LDL When the value is 474.5m U/m L,the sensitivity is 70.63% and the specificity is62.69%;while the ROC curve drawn by RC combined with Ox-LDL can improve the diagnostic value of CHD(AUC=0.763 95%CI:0.696～0.830;P<0.001).5.After follow-up of all-cause deaths in patients with coronary heart disease,they were divided into survival group and death group.Analysis of the difference of Ox-LDL and RC between the two groups found that the RC level of the death group was significantly higher than that of the survival group(P<0.001).There was no significant difference in Ox-LDL levels(P=0.157).The ROC curve was used to evaluate the predictive value of Ox-LDL and RC for the death of patients with coronary heart disease.The results found that RC has a higher predictive value for the risk of all-cause death in patients with coronary heart disease within 4 years after discharge(AUC=0.756,95%CI: 0.627),0.885;P<0.01;cutoff value 0.775mmol/L;sensitivity 71.43%,specificity 74.11%);and Ox-LDL cannot predict the all-cause mortality of patients with coronary heart disease within 4 years after discharge(P=0.864).6.Grouping according to the best cut-off value of RC and conducting survival analysis found that the 4-year mortality rate of patients with coronary heart disease in the RC≥0.775 group(10 cases/39 cases,25.64%)was higher than that in the RC<0.775 group(4 cases/87 cases,4.60%))Significantly increased(P<0.001).Conclusion: 1.There is a positive correlation between Ox-LDL and RC.The correlation between high levels of RC and high Ox-LDL levels might be linked to atherogenesis in patients with CAD.2.Ox-LDL,RC,TG,LDL-C,N-HDL-C and HDL-C are all independent risk factors for CHD.The value of Ox-LDL in the diagnosis of coronary heart disease is better than other lipid indicators.The combined analysis of LDL and RC can improve the value of evaluating CHD diagnosis.3.The RC level has a good predictive value for the long-term death of patients with coronary heart disease,which is helpful for the identification and risk stratification of high-risk patients;in this study,Ox-LDL did not show the predictive value for the long-term death of patients with coronary heart disease.