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

Abstract

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 (ICAM-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 (HbA 1c) and lipid profile were estimated. Results Percentage of HbA 1c, lipids, MDA, hsCRP, ET-1, P-selectin, ICAM-1, and VCAM-1 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.