ASSOCIATIONS OF LIPOPROTEIN CHOLESTEROLS, APOLIPOPROTEIN-A-I AND APOLIPOPROTEIN-B, AND TRIGLYCERIDES WITH CAROTID ATHEROSCLEROSIS AND CORONARY HEART-DISEASE - THE ATHEROSCLEROSIS RISK IN COMMUNITIES (ARIC) STUDY

Previous research shows generally greater proportional elevation in ap olipoprotein B (apoB) levels than in low-density lipoprotein cholester ol (LDL-C) in coronary heart disease (CHD) case subjects compared with control subjects. The Atherosclerosis Risk in Communities study provi ded general populations of 7261 men and women free of cardiovascular s ymptoms for evaluating the associations between intima-media thickenin g in extracranial carotid arteries measured using ultrasound imaging a nd fasting plasma LDL-C, high-density lipoprotein cholesterol (HDL-C), apoB, apolipoprotein A-I (apoA-I), triglycerides, and HDL density sub fractions. A CHD group was selected for comparison. Lipid factors show approximately linear associations with carotid thickness: positive fo r LDL-C and plasma apoB and negative for HDL-C and apoA-I levels. Apol ipoproteins and HDL density subfractions did not contribute to the ass ociation after accounting for LDL-C and HDL-C. Compared with control s ubjects, persons whose carotid thickness exceeded 0.9 mm had greater p roportional elevations in LDL-C than in apoB, whereas HDL-C reductions were small. CHD case subjects showed greater proportional elevations of apoB than LDL-C. Although the lipid profiles associated with asympt omatic carotid wall thickening and stenotic coronary disease are simil ar, the differences found suggest that LDL-C is the most important lip id factor in earlier stages of atherogenesis, whereas the metabolism o f triglyceride-rich lipoproteins and its effects on LDL and HDL may be more relevant to later atherothrombotic processes.