Are apolipoproteins A and B better than lipoproteins for assessing risk of obstructive coronary heart disease?

OBJECTIVE To evaluate whether apolipoproteins A-I (Apo A-I) and B (Apo B) have, higher ensitivity (SN), specificity (SP) and positive predictive value (PPV) than lipoproteins (LP), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides (TGL) in assessing the risk of coronary heart disease (CHD). METHODS This is a transversal case-control study of 241 patients, who were divided into two groups: 1) 145 patients with CHD, and 2) 96 patients without coronary disease. A model of logistic regression to evaluate the relation between the LPs and CHD was developed in which variables with a p-alpha < 0.1 were included. RESULTS Apo A-I levels were higher in the patients without CHD, (OR 2.08, CI 1.20-3.57). There were no statistical differences between the values of Apo A-I and the remaining lipid fractions (Apo A-I: 67%; Apo B: 100%; PPV: TC = 71%; TGC = 71%; HDL = 71%; LDL = 71%). The costs of the tests in Reais were as follows: Apo A-I: R$ 56.60; Apo B-100: R$ 56.60; TC: R$ 9.94; HDL: R$ 21.30; LDL: R$ 28.40; TGL: R$ 14.20. CONCLUSION Levels of Apo A-I and Apo B have no advantage over conventional lipoproteins in predicting the risk of CHD, despite the statistical association between Apo A-I and CHD; in addition, their costs are higher than those of the conventional lipoproteins.