Abstract 12554: Circulating Eosinophil Count is Associated With Thoracic Aortic Wall Thickness Evaluated by Computed Tomography

Abstract

Background and Purpose: Eosinophil count is known to be increased in various forms of arteritis/aortitis that may potentially lead to vascular wall thickening. We investigated whether circulating eosinophil count is associated with aortic wall thickness. Methods: Subjects who underwent 320 detector-row computer tomography (Toshiba Medical Systems, Tokyo, Japan) to evaluate the coronary artery were enrolled in the study. Aortic wall thickness was measured perpendicularly to the center of the aorta in the axial image. The protruding atheroma was defined as the maximum aortic wall thickness of ≥4 mm with irregular surface. Results: This study included 405 patients (255 men) with mean age 67.6 +/- 10.5 years old. Those patients with aortic wall thickness of ≤2 mm (n=109), 2-2.9 mm (n=179), 3-3.9 mm (n=70), and ≥4 mm (n=47) had eosinophil count (cells/μL) of 120.0, 130.3, 133.2 and 222.4, respectively. Eosinophil count was positively associated with aortic wall thickness (R 2 =0.034, P<0.001), meanwhile, neutrophil, monocyte, basophil and lymphocyte count were not. By multiple regression analysis using eosinophil count and other potential confounders including sex, age, BMI, systolic blood pressure, lipid and glucose profile, and renal function as independent variables, eosinophil count was selected as a factor that had significant association with aortic wall thickness with correlation coefficient of 0.172 (95% confidence interval 0.001-0.003, p<0.0001). In addition, multiple logistic regression analysis using eosinophil count tertile and other atherosclerotic risk factors as independent variables showed that the 2 nd and 3 rd eosinophil count tertile were independently associated with protruding atheroma with an odds ratio of 2.82 (95% confidence interval 1.16-6.80, P=0.022) and 5.75 (95% confidence interval 1.79-18.52, P=0.003). Conclusions: Eosinophil count was associated with thoracic aortic wall thickness. Considering that circulating eosinophil is increased in various immuno-inflammatory aortic disease, histopathologic analyses should be performed to investigate whether there is any causal and resultant relationship underlying this observed link between eosinophil and aortic wall thickening.