Fasting triglyceridemia influences postprandial endothelial response to a single Mediterranean-type meal compared to a high-saturated fat meal

Endothelial dysfunction is considered a precursor of atherosclerosis and is an independent predictor of cardiovascular events. A high-saturated fat meal (HSFAM) has been shown to induce postprandial endothelial dysfunction. However, no studies have evaluated the acute endothelial effect of a single mixed Mediterranean-type meal (MMM). Our objective was to evaluate postprandial endothelial and metabolic function in response to a MMM in comparison to an isocaloric HSFAM and explore the role of baseline triglyceridemia. In this crossover study, 28 healthy non-smoking males were randomly assigned two isocaloric meals on two separate mornings. The MMM, consisting of salmon, almonds and vegetables baked in olive oil, provided 51% of total calories from fat (7.87g SFA and 2.29g of omega-3) while the HSFAM, consisting of sausage, egg and cheese sandwich and fried potatoes, provided 58% of total energy from fat (14.78g SFA). Endothelial function was evaluated by brachial artery flow-mediated dilation (FMD) after a 12-hour fast (T0) and four hours after consumption of the meals. Fasting and postprandial plasma fatty acid profiles were also evaluated. Postprandial FMD was significantly reduced by the HSFAM (-2.5±3.6%, p=0.004), while it was not influenced by the MMM (-1.21±4.6%, ns). Postprandial insulin, AUC TG, TG/HDL and C/HDL were increased to a greater degree in response to the HSFAM. Plasma enrichment in omega-3 PUFA (EPA, DPA and DHA) at the expanse of SFA (18:0) was observed following the MMM. Furthermore, postprandial FMD was significantly reduced by the HSFAM only among individuals with fasting TG levels above the group median (0.87 mmol/L). A single MMM exerts no deleterious effect on postprandial endothelial function and has a lesser impact on metabolic profile than does a HSFAM. This could be resulting from significant postprandial enrichment in fatty acids with better endothelial properties. Moreover, even slightly elevated but normal fasting triglyceridemia could increase the risk of endothelial injury following a single HSFAM.