Enhanced Peripheral Vasodilation in Humans After a Fatty Meal

Objectives: We sought to study the effects of a fatty meal on vascular reactivity, including endothelial function and maximal vasodilation.

Background: Recent reports regarding the physiological changes in peripheral vasculature after eating a fatty meal have been controversial.

Methods: Twelve volunteers were studied before, 3 h after, and 6 h after a high-fat meal (1030 kcal, 61 g fat) rich in saturated fatty acids, and 10 were restudied after a similar meal rich in monounsaturated fatty acids. Endothelial function was assessed as flow-mediated dilatation (FMD) in the brachial artery using ultrasound. Resting and postischemic forearm blood flow (FBF) were recorded using venous occlusion strain-gauge plethysmography, before, and every 10 to 15 s after, 5 min upper arm ischemia.

Results: Brachial artery basal diameter, resting FBF and postischemic hyperemia increased after high-fat meals (all p<0.001), whereas FMD did not change. The increase in resting FBF correlated with increases in postprandial insulin (r = 0.80, p<0.002) and triglyceride (r = 0.77, p<0.005) levels.

Conclusions: We concluded that eating a fatty meal induces vasodilation and increases resting and stimulated FBF and that these observations are probably mediated by postprandial changes in insulin and/or triglyceride levels. The metabolic changes that occur after meals are not associated with impaired endothelial nitric oxide release in the conduit arteries.