Abstract 12565: Association of Very Low-density Lipoprotein Cholesterol With Coronary Artery Calcification in Type-2 Diabetes
Background: Recent genomic studies have refocused attention on triglyceride (TG) rich lipoproteins in cardiovascular disease (CVD). Although serum TGs have been extensively studied, little is known of very low-density lipoprotein cholesterol (VLDL-C) relationship with atherosclerosis and CVD. We examined, in a high-risk type-2 diabetic population, the association of plasma VLDL-C with coronary artery calcification (CAC), a measure of coronary atherosclerosis that predicts CVD.
METHODS: The Penn Diabetes Heart Study (PDHS) is a cross-sectional study of CVD risk factors in type-2 diabetics (n=2118, mean age 59.1 years, 36.5% female, 34.1% Black). Plasma lipids including VLDL-C were measured after ultracentrifugation on a Hitachi 912 Analyzer. CAC scores were quantified by the Agatston method from electron beam CTs. Tobit regression was used to assess the independent relationship of VLDL-C with CAC.
Results: VLDL-C levels (mg/DL) were associated with gender [26, IQR (18-39) men, 22, (IQR 15-34) women, P=0.0001], race [27, (IQR 18-39) Whites, 21, (IQR 15-30) Blacks, P= 0.0001], body mass index (BMI) (Spearman R 0.14, P≤0.0001), plasma TGs (R 0.88, P≤0.0001), apoB (R 0.45, P≤0.0001) and HDL-cholesterol (R -0.42, P≤0.0001). In Tobit regression, VLDL-C levels were positively associated with increasing CAC after adjusting for age, race, gender, Framingham risk score, BMI, C-reactive protein, exercise, medication and alcohol use, hemoglobin A1c, and diabetes duration [Tobit ratio (TR) and 95% confidence interval (CI) 0.38 (0.13-0.64), P=0.005] and even after inclusion of apoB data [TR 0.31 (0.03-0.58), P=0.03]. Approximately 3-fold stronger effect was observed in women [TR 0.74 (0.15 - 1.32), P=0.014] than men [TR 0.20 (-0.10-0.50), P=0.19; gender interaction P=0.03]. VLDL-C had stronger CAC association in individuals with TGs >150mg/dl (TR 0.80, P=0.01) vs. those with TGs ≤150 mg/dl (TR 0.26, P=0.20).
Conclusions: In PDHS, VLDL-C is associated with CAC independent of established CVD risk factors, particularly in women, and has value even beyond apoB levels and when TGs are elevated. Further study is warranted of plasma VLDL-C and other markers of TG-rich lipoproteins in predicting CVD in high-risk patients and as markers in genomic and therapeutic trials.
- © 2013 by American Heart Association, Inc.