Lymphocyte DNA damage is associated with increased aortic intima-media thickness

OBJECTIVES: To investigate whether there is an association between lymphocyte DNA damage and aortic intima-media thickness (IMT). METHODS: We studied 70 patients (mean age: 41.6+/-10 years) who underwent transesophageal echocardiography for various indications. Four different grades were determined according to intima-media thickness (IMT) of thoracic aorta measured by transesophageal echocardiography. DNA damage was assessed by alkaline single cell electrophoresis (comet) assay in peripheral lymphocytes. Plasma level of total antioxidant status (TAS) was determined by using automated measurement method. High sensitive C-reactive protein and other biochemical markers were studied in all subjects. RESULTS: The major increase in lymphocyte DNA damage was observed in patients with grade 4 IMT when compared with other groups (p<0.001, for all). Lymphocyte DNA damage of patients with grade 1 IMT was also lower than patients with grade 2 IMT (p=0.013) and patients with grade 3 IMT (p<0.001). Lymphocyte DNA damage of patients with grade 2 IMT was found at low level compared with patients with grade 3 IMT (p=0.012) as well. In multiple linear regression analysis, IMT was independently correlated with lymphocyte DNA damage (beta=0.515, p<0.001), TAS level (beta=-420, p<0.001), total cholesterol (beta=0.407, p<0.001) and LDL cholesterol level (beta=287, p=0.020). CONCLUSION: Lymphocyte DNA damage may be an independent predictor for the grade of thoracic IMT, and may play a role in pathogenesis of thoracic atherosclerosis besides TAS and cholesterol levels.