Abstract

BACKGROUND
Endothelial dysfunciton has been proposed as an early manifestation of atherogenesis. Recently, emerging evidence suggests that hypertriglyceridemia and elevated free fatty acid are important risk factors in the development of atherosclerosis, probably through an increased oxidative stress. To clarify the hypothesis, we evaluated the effect of alpha-lipoic acid (ALA) on the endothelial dysfunction induced by intralipid infusion in healthy volunteers. METHODS: Hypertriglyceridemia and elevated free fatty acids was induced by infusion of intralipid. FMD (Flow-mediated dilation) of the brachial artery was investigated noninvasively by a high-resolution ultrasound technique in 13 young, healthy men without risk factors for coronary heart disease. RESULTS: Plasma triglyceride, free fatty acid and the superoxide anion were increased from 61.7+/-28.8 to 332.6+/-202.5 mg/dL, from 330.7+/-131.1 to 1267.0+/-486.2 microEq/L and from 6.6+/-2.2 to 8.7+/-1.5 X 10(-7)nmol/10(6)cells/30min (vs. basal p<0.001), respectively, following infusion of the intralipid. The FMD was decreased from 10.1+/-3.3 to 7.7+/-3.7% (vs. basal p<0.01) following infusion of the intralipid. After treatment with ALA, the increase in the FMD and the decrease in superoxide anion were significant. CONCLUSION: Acute hypertriglyceridemia, induced by intralipid infusion, is implicated in endothelial dysfunction. This endothelial dysfunction was reversed by treatment with ALA. These results suggest that chronic and repeated hypertriglyceridemia may play important roles in the development of atherosclerosis probably by increasing oxidative stress.

• Keywords: Endothelial dysfunction;Oxidative stress;Antioxidants;Lipoic acid;