An ordinary mixed meal transiently impairs endothelium-dependent vasodilation in healthy subjects

This study was designed to evaluate the effects of an ordinary mixed meal o n endothelium-dependent vasodilation. Ten young healthy volunteers were giv en a mixed meal (minced meat sauce with rice, 900 kcal, 34% of the energy c ontent was fat). In the fasting state, at 60 and 120 min after the start of the meal, endothelium-dependent vasodilation and endothelium-independent v asodilation were evaluated by local infusion of metacholine (4 mug min(-1)) and sodium nitroprusside (10 mug min(-1)) in the brachial artery. Blood fl ow in the forearm was measured using venous occlusion plethysmography. Endo thelium-dependent vasodilation decreased from 15.4 +/- 3.3 (mean +/- SD) at fasting to 13.7 +/- 3.5 mL min(-1) (100 mL tissue)(-1) (P < 0.01) 60 min a fter feeding, but had returned to the fasting level at 120 min. At 60 min, but not in the fasting state, the serum level of free fatty acids was inver sely related to endothelium-dependent vasodilation (r= -0.74, P < 0.05), al though no significant net changes in FFA levels were seen. Endothelium-inde pendent vasodilation was not affected by the mixed meal. No similar attenua tions in endothelium-dependent vasodilation were seen during control meals. In conclusion, an ordinary mixed meal transiently attenuated endothelium-d ependent vasodilation. Free fatty acids may be involved in this effect on e ndothelial function.