Supplements of l-arginine attenuate the effects of high-fat meal on endothelial function and oxidative stress

Background Postprandial hypertriglyceridemia is known to cause endothelial dysfunction and increased oxidative stress. Oral supplements of l-arginine have been found to improve endothelial function. However, the effects of supplements of l-arginine on the influences of postprandial hypertriglyceridemia were not studied before. Methods Forty young healthy men without any risk factors were equally divided into two groups. l-arginine group (age 22 ± 1 years, body mass index 23.5 ± 1.2 kg/m2) received a standard high-fat meal with 15 g oral l-arginine. Control group (age 22 ± 1 years, body mass index 23.8 ± 0.9 kg/m2) received a standard high-fat meal with placebo. A standard high-fat meal consisted of 900 kcal and 50 g of fat. Flow-mediated vasodilation (FMD), von Willebrand factor (vWF), p-Selectin, and glutathione peroxidase (GSH-Px) were measured before and 2 h after the high-fat meal. Results Serum triglyceride levels were significantly increased 2 h after the high-fat meal in both groups. In the control group, FMD (10.5 ± 1.2% vs. 6.8 ± 1.4%, p < 0.001) and GSH-Px (23.5 ± 6.2 vs. 21.9 ± 5.0 μg/ml, p = 0.029) were significantly decreased after the high-fat meal. P-Selectin (20.0 ± 7.7 vs. 25.9 ± 10.5 mg/l, p = 0.025) and vWF (731.2 ± 131.5 vs. 934.9 ± 133.8 mU/ml, p < 0.001) were significantly increased after the high-fat meal. In the l-arginine group, FMD (10.3 ± 1.3 vs. 9.3 ± 0.9%, p < 0.001) was slightly but significantly decreased after the high-fat meal but not GSH-Px (23.6 ± 3.6 vs. 23.0 ± 4.8%, p = 0.468). P-Selectin (20.1 ± 5.9 vs. 25.7 ± 10.2 mg/l, p = 0.001) and vWF (793.2 ± 146.0 vs. 944.4 ± 136.8 mU/ml, p < 0.001) were significantly increased after the high-fat meal. Degree of FMD attenuation following the high-fat meal was significantly less in the l-arginine group (1.0 ± 0.9 vs. 3.8 ± 1.5%, p < 0.001). Conclusions Concomitant supplements of l-arginine improved endothelial dysfunction and oxidative stress induced by postprandial hypertriglyceridemia. However, changes of p-Selectin and vWF were not affected by supplements of l-arginine with the high-fat meal.