The Study Of The Correlation Between Small And Dense Low-density Lipoprotein Cholesterol And The Characteristics Of Coronary Artery Disease

Part ? Performance verification of small and dense low density lipoprotein cholesterol by peroxidase methodObjective:To evaluate whether the sdLDL-C kit used in this subject is applicable on the Beckman Coulter DXC800 biochemical analyzer and to ensure the reliability of the study results.Methods:According to the Clinical Laboratory Improvement Amendments of 1988(CLIA88),Clinical and Laboratory Standards Institute(CLSI)and the National Health and Family Planning Commission of the People's Republic of China,the precision,accuracy and linearity of the kit were carried out.Results:?The Intra-batch coefficient of variation(CV)and total CV were 4.88%and 5.01%at low concentration level of 0.256 mmol/L,respectively,The Intra-batch CV and total CV were 2.99%and 3.19%at low concentration level of 1.469 mmol/L,respectively;?24 Samples covered the linear range and were measured in the other one laboratory were collected for accuracy evaluation,they were tested in our laboratory on the same day,correlation coefficient was 0.9917 for the two groups of data,and the average relative bias was 4.47%;?The high-value mixed samples were diluted according to different ratios with low-value mixed samples to obtain samples with 6 concentration levels.The measured values were taken as ordinate,and the theoretical values were calculated as abscissa.The linear equations were y=1.004x-0.035,r2=0.998,and can meet the requirement of the regent kit instructions.Conclusions:The precision,accuracy and linearity of sdLDL-C peroxidase test kit provided by Beijing Jiuqiang Biotechnology Company can meet the requirement and can Provide reliable results for the next clinical study.Part ? Correlation between small,dense low density lipoprotein cholesterol and characteristics of coronary atherosclerosisObjective:To evaluate the association between small,dense low-density lipoprotein cholesterol(sdLDL-C)and severity of coronary atherosclerosis disease(CAD).Methods:A total of 436 outpatients with suspected CAD and underwent coronary computed tomography(CT)were consecutively enrolled from July 2015 to March 2016 in Fuwai hospital.Correlation between serum sdLDL-C and the severity of CAD including characteristics of plaque,the number of stenosed coronary vessels,the degree of stenosis was analysed.Results:SdLDL-C was positively correlated with non high-density lipoprotein cholesterol(nonHDL-C),apolipoprotein B(apoB),triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),blood glucose(Glu)(coefficient correlation were0.645,0.643,0.630,0.559,0.434,0.148 successively,P<0.01),and negatively correlated with high-density lipoprotein cholesterol(HDL-C)(r=-0.239,P<0.01).SdLDL-C was a risk factor for severe CAD(multivessel lesion and severe stenosis),independent of traditional risk factors(age,gender,hypertension,diabetes,smoking,alcohol consumption,renal dyfunction)and the use of lipid-lowering agents;For patients with triple-vessel disease,odds ratio of TG,LDL-C,TC,nonHDL-C,sdLDL-C,sdLDL-C/LDL-C and apoB were 1.531,2.256,2.443,2.900,5.175,5.477and 31.73 successively.And for patients with severe stenosis,LDL-C was not an independent factor,while TC,TG,nonHDL-C,sdLDL-C and apoB still had predictive value(odds ratio were 1.505,1.597,1.702,2.096 and 10.39 successively);For vulnerable plaque,sdLDL-C was not an independent factor,while TG,nonHDL-C and apoB still had predictive value(odds ratio were 1.317,1.463 and 5.584successively).Conclusions:SdLDL-C is a predictor of severe CAD independent of traditional risk factors that may be useful for further risk stratification in patients with CAD.