Serum vitamin E concentration in Iranian population with angiography defined coronary artery disease

Abstract

Background: Oxidative modification of low-density lipoprotein (LDL) seems to play a role in the development of atherosclerosis and coronary artery disease (CAD). Although in many experiments a role for vitamin E in prevention of LDL oxidation and therefore CAD has been suggested, some clinical studies have failed to confirm these findings. Objective: A case- control study was conducted to find out the association between serum vitamin E levels and coronary artery disease susceptibility in Iranian patients with CAD. Methods: Ninety-one patients with angiographically confirmed CAD (defined as coronary obstruction >50%) and 39 age and sex matched controls that their atherosclerosis was not proven according to angiography were included. Serum vitamin E concentration was measured in plasma by high performance liquid chromatography (HPLC) for all patients. Results: No significant difference in serum levels of vitamin E and standardized vitamin E [vitamin E/total cholesterol, and vitamin E/ (total cholesterol+triglycerides)] and lipid profile parameters was observed between patients and control groups. The association between vitamin E and CAD remained unchanged independent of age, sex, smoking habit, hypertension, hyperlipidemia and diabetes. Serum vitamin E levels were positively associated with waist/hip ratio, high-density lipoprotein cholesterol (HDL-C) and total cholesterol in the control group and inversely associated with HDL-C in the CAD group. Vitamin E/total cholesterol levels were inversely associated with HDL-C and low-density lipoprotein cholesterol (LDL-C). Conclusion: Our data does not support the results of other studies which have shown an association between lower amounts of vitamin E and enhanced risk of coronary heart disease. Keywords: Coronary artery disease, HPLC, LDL-cholesterol, LDL oxidation, vitamin E