Abstract

Objective — Evidence favors apolipoprotein B (apoB) over LDL-Cholesterol (LDL-C) as a predictor of cardiovascular events but data is lacking on coronary artery calcification (CAC), especially in type 2 diabetes, where LDL-C may underestimate atherosclerotic burden. We investigated the hypothesis that apoB is a superior marker of CAC relative to LDL-C.

Research Design and Methods — We performed cross-sectional analyses of Caucasian subjects in two community-based studies: the Penn Diabetes Heart Study [(PDHS) N=611 type 2 diabetic subjects, 71.4% men] and the Study of Inherited Risk of Coronary Atherosclerosis [(SIRCA) N=803 non-diabetic subjects, 52.8% men)] using multivariate analysis of apoB and LDL-C stratified by diabetes status.

Results — In type 2 diabetes, apoB was associated with CAC after adjusting for age, gender, and medications [Tobit regression ratio of increased CAC for one standard deviation increase in apoB; 1.36 (95% CI 1.06-1.75), p=0.016] whereas LDL-C was not [1.09 (0.85-1.41)]. In non-diabetic subjects, both were associated with CAC [apoB 1.65 (1.38-1.96), p<0.001; LDL-C 1.56 (1.30-1.86), p<0.001]. In combined analysis of diabetic and non-diabetic subjects, apoB provided value in predicting CAC scores beyond LDL-C, total cholesterol, the total cholesterol/HDL-C and triglyceride/HDL-C ratios, and marginally beyond non-HDL-C.

Conclusions — Plasma apoB, but not LDL-C, levels were associated with CAC scores in type 2 diabetic Caucasians. ApoB levels may be particularly useful in assessing atherosclerotic burden and cardiovascular risk in type 2 diabetes.