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, mean26 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, mean50 yr) and 10 diabetes (DM, mean48 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.