Relationship between plasma total antioxidant capacity and thoracic aortic intima-media thickness.

It is known that antioxidants have an important role in the prevention of coronary artery disease (CAD). Low total antioxidant capacity (TAC) is a risk factor for ischemic heart disease. However, no data are available concerning the relationship between TAC and severity of thoracic aortic atherosclerosis. This study using multiplane transesophageal echocardiography (TEE) examined the relationship between atherosclerotic thoracic aortic intima-media thickness (TAIMT) and TAC. Twenty-nine patients (17 male, 12 female; mean age 36 +/- 8 years) without a history of atherosclerotic cardiovascular disease referred for TEE were included. The patients with obesity, hypertension, diabetes, and CAD were excluded. The TAC was measured for each patient using a more recently developed method. TAIMT and grade of thoracic aortic atherosclerosis were evaluated in each patient by using TEE. Mean TAC level was 1.91 +/- 0.53 mmol Trolox equiv/l. There was a negative and significant correlation between the TAC levels and TAIMT and grade of thoracic aortic atherosclerosis (r = -0.799, P < 0.001 versus r = -0.827, P < 0.001, respectively). Multiple linear regression analysis showed that TAIMT was independently associated with TAC (beta = -0.734, P < 0.001). The mean values of TAC in grade I, II, and III were 2.23 +/- 0.31, 1.58 +/- 0.31, and 1.04 +/- 0.27 mmol Trolox equiv/l, respectively (ANOVA P < 0.001). This study indicates that the TAC is an independent variable for TAIMT and it has a potential for an independent variable for atherosclerotic lesions in the major arterial locations.