Lipoprotein(a) Is A Risk Factor For Coronary Artery Disease In Chinese Han Ethnicity Population Modified By Some Traditional Risk Factors: A Cross-sectional Study Of 3462 Cases And 6125 Controls

Objective: There are racial/ethnic differences in the distribution of Lipoprotein(a)[Lp(a)]. Adequate amount of studies in Caucasian have been made in the western world, while there was lack of influential study in Chinese Han ethnicity. This large sample cross-sectional study was conducted to assess the role of elevated Lp(a) as a coronary risk factor in Chinese Han ethnicity, and the interaction between Lp(a) and other risk factors.Methods: General information and clinical laboratory data was collected from the consecutive patients admitted in the Division of Cardiology, First Affiliated Hospital to Soochow University between 2010 and 2013. Patients were divided into coronary artery disease(CAD) group and no coronary artery disease(non-CAD) group. CAD group was divided into initial Ischemic Heart Disease(IHD), initial Myocardial Infarction(MI) and prior CAD. Multivariate logistic regression modeling was used to explore the association between Lp(a) and CAD.Results: Of the 13834 candidates, patients who were suffering thyroid disease, liver and kidney function abnormalities, didn’t take the Lp(a) test, and admitted in the hospital again were excluded.The patients were divided into 3462 cases and 6125 controls. There was a very broad skewed distribution of Lp(a) plasma concentration. On a continuous scale, a 10mg/d L increase in lipoprotein(a) levels was associated with a crude OR of 1.082(95%CI, 1.063-1.102, P<0.0001) for CAD, 1.101(95%CI, 1.080-1.132, P<0.0001) as partially adjusted for gender, age, body mass index(BMI),drinking, smoking, hypertension, diabetes mellitus, LDL cholesterol,HDL cholesterol,triglycerides, atherosclerosis, ischemic encephalopathy, hemorrhagic encephalopathy, associated with 1.100(95%CI, 1.078-1.122, P<0.0001) as fully adjusted for all above characteristics and alanine aminotransferase, albumin, Creatinine and test year. We defined Lp(a) cut points on the basis of quintiles of the controls’ distribution. Fully adjusted risk ratios for CAD were 1.243(95% CI, 1.063-1.454, P<0.001) for the 2nd quintile, 1.339(1.146-1.564, P<0.0001) for the 3rd quintile, 1.493(1.281-1.740, P<0.0001) for the 4th quintile, and 2.112(1.819-2.451, P<0.0001) versus the 1st quintile. There was interaction between Lp(a) and hypertension, BMI and total cholesterol in initial IHD, while Creatinine in prior CAD. There was no interaction between Lp(a) and other risk factors in initial MI.Conclusion: There was a stepwise increase in risk of CAD with increasing concentration levels of serum Lp(a) in Chinese Han ethnicity. Lp(a) is a risk factor for coronary heart disease.