Influence of vitamin E supplementation on endothelial complications in type 2 diabetes mellitus patients who underwent coronary artery bypass graft

Background: Diabetes mellitus (DM) is associated with increased risk for complications following coronary artery bypass graft (CABG) surgery, in which tissue damage involves leukocyte-endothelial interactions mediated by endothelin-1 (ET-1) and adhesion molecules (AMs). Aim: This study compared lipids and their peroxidation product, malondialdehyde (MDA), high-sensitivity C-reactive protein (hsCRP), ET-1, platelet-selectin (P-selectin), intercellular AM-1 (VCAM-1), and vascular cell AM-1 (VCAM- 1) between healthy controls and type 2 DM subjects who did not receive CABG surgery as well as those who did. Vitamin E as an adjunctive therapy in subjects who underwent CABG was evaluated. Methods: ELISA was used to measure hsCRP, ET-1, and AMs. For all subjects, glycosylated hemoglobin) and lipid profile were estimated. Results: Percentage of HbA(1c), lipids, MDA, hsCRP, ET-1, P-selectin, ICAM-1, and VCAM-1 (HbA(1c)) levels were significantly higher in the diabetic groups than in healthy controls. Vitamin E supplementation for 3 successive months significantly lowered MDA, hsCRP, ET-1, ICAM-1, and VCAM-1 levels by 64%, 47%, 12%, 74%, and 25%, respectively. However, high-density lipoprotein cholesterol (HDL-C) and vitamin E serum levels were increased by 65% and 90.55%, respectively (P <= .05). Vitamin E cosupplementations correlated restored ET-1, P-selectin, and ICAM-1 levels, which have been functionally damaged by decreased HDL-C, hypercholesterolemia, and hypertriacylglycerolemia, respectively. Conclusion: This study indicates that increased levels of the proinflammatory markers and AMs occur in type 2 DM. Vitamin E administration appears beneficial in lowering proinflammatory markers and their downstream effectors that played an important role in diabetic complications following CABG. (C) 2009 Elsevier Inc. All rights reserved.