Abstract 530: Impact of a Single Mixed Mediterranean-Type Meal Compared with a High-Saturated Fat Meal on Postprandial Endothelial Function and Metabolic Markers
Background: Endothelial dysfunction is considered a precursor of atherosclerosis and is an independent predictor of cardiovascular events. A high-saturated fat meal (HFM) 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 HFM. Methods: In this ongoing crossover study, 26 of 28 healthy non-smoking males have completed the research protocol. In random order on two separate days during a 1-week interval, subjects were fed two isocaloric meals after an overnight fast. The MMM (885 kcal) consisted of fresh salmon, almonds and vegetables baked in olive oil providing 51% of total calories from fat (7.87g SFA and 2.29g of omega-3, 2:1 DHA:EPA). The HFM consisted of a McDonald’s sausage, egg and cheese McMuffin and three hashbrowns (858 kcal) providing 58% of total energy from fat (14.78g SFA and no omega-3). Endothelial function was evaluated by measuring brachial artery flow-mediated dilation (%FMD) at baseline and at two (T2) and four (T4) hours postprandial. Results: Mean postprandial %FMD tends to be less impaired following the MMM than the HFM (variation at T4 -0.15±3.6% vs -2.83±3.3% respectively, p<0.1). Postprandial variations of TG and TG/HDL at T4 were also less severe with the MMM than the HFM (p≤0.05) and did not correlate to %FMD variations. When subdividing the population on the basis of the median fasting TG levels (0.90 mmol/L), the HFM led to significant endothelial impairment in the subjects with higher-TG while it had no effect in the low-TG group. Conclusion: Our data suggest that a single MMM exerts less of a deleterious effect on postprandial endothelial function and metabolic markers than does a HFM. A single MMM could thus be less atherogenic than a HFM. Moreover, subjects with higher fasting TG levels (avg. 1.54±0.59 mmol/L, well bellow hypertriglyceridemia threshold) could be at higher risk of endothelial injury following a single HFM. Data on all 28 subjects will be available in April 2012.