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.

Keywords: ET-1, Adhesion molecules, Type 2 DM, CABG, Vitamin E