The Effect of Vitamin E on the Endothelial Function Following a Single High-Fat Meal in Normal Subjects, Patients with Coronary Heart Disease and Patients with Diabetes

ABSTRACT

BACKGROUND AND OBJECTIVES: The hyperlipidemia by a high-fat diet induce the endothelial dysfunction. We have performed this study to determine the relationship between postprandial hypertriglyceridemia and endothelial function and to know the effects of vitamin E on the endothelial function. MATERIALS AND METHOD: Endothelial function was measured by flow-mediated brachial artery vasodilation (FMD) as percent diameter changes. We have serially measured lipid profiles and FMD after a meal in normal subjects (10 males, mean:26 yr), which test was repeated according to types of meal (high-fat, low-fat and high-fat meal with 800 IU vitamin E). The second stage of this study is consisted of 10 patients with coronary artery disease (CAD, mean:50 yr) and 10 diabetes (DM, mean:48 yr). RESULTS: The serum triglycerides were significantly increased at 2 and 4 hours after a high-fat meal. The FMD was transiently decreased (p<0.001) to 7+/-4% and 7+/-2% at 2 and 4 hours only after a high-fat meal from 13+/-4% at fasting state. The FMD was inversely related with postprandial hypertriglyceridemia (r=0.52, p<0.05). The baseline FMD in patients with CAD and DM were all lower, 9+/-4% and 10+/-5% respectively, than 15+/-2% of normal subjects. The FMD in patients with CAD were improved to 13+/-4%, 13+/-4% and 11+/-6% at 2, 4, and 6 hours after a meal plus vitamin E, respectively. The FMD in diabetic patients were not decreased as same manor in normal subjects. CONCLUSION: The vitamin E can prevent the endothelial dysfunction which is induced by postprandial hypertriglyceridemia in normal subjects and can improve the endothelial dysfunction in patients CAD as well as DM.