Relationship between Serum Lipid Values and Atherosclerotic Burden in the Proximal Thoracic Aorta

Abstract

We conducted a cross-sectional analysis in a population-based cohort to compare the strength of the associations among various lipid parameters and the presence of atherosclerotic plaque in the proximal thoracic aorta. As part of Aortic Plaques and Risk of Ischemic Stroke (APRIS) study, 464 subjects were studied (mean age 69.1 +/- 9.0, 251 males and 213 females), including 255 patients with first ischaemic stroke and 209 stroke-free controls. Presence and thickness of atherosclerotic plaque were assessed by transoesophageal echocardiography. Measured lipid parameters included total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, and non-high-density lipoprotein cholesterol, lipoprotein (a), apolipoprotein (Apo) B and A-I levels with their ratio. Overall, atherosclerotic plaque was detected in 326 subjects (70.4%) and 37.6% of these subjects (n=174) had atherosclerotic plaque > or =4 mm. After adjusting for other significant predictors of atherosclerosis, high-density lipoprotein cholesterol level and Apo B/A-I ratio emerged as the strongest predictors of any atherosclerotic plaque (P<0.001 and P=0.004, respectively), followed by individual Apo B (P=0.015) and A-I (P=0.016) levels, triglycerides (P=0.027) and non-high-density lipoprotein cholesterol level (P=0.021). Total and low-density lipoprotein cholesterol levels were not significant predictors for any atherosclerotic plaque (P=0.273 and P=0.081, respectively). High-density lipoprotein cholesterol level (P=0.008) and Apo A-I (P=0.006) were also significant predictors of atherosclerotic plaque > or =4 mm. Similar trends were observed after exclusion of subjects on cholesterol lowering drugs. High-density lipoprotein cholesterol level and Apo B/A-I ratio, but not total or low-density lipoprotein cholesterol levels, were strongly associated with degree of proximal aortic atherosclerosis.