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.

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).

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.

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.