Relationship between serum lipid values and atherosclerotic burden in the proximal thoracic aorta.

BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.