Endothelial dysfunction induced by post-prandial lipemia: complete protection afforded by high-intensity aerobic interval exercise

Abstract

Objectives: This study was designed to study the effect of exercise and a high-fat meal (HFM) on endothelial function.

Background: Post-prandial lipemia and exercise oppose each other in terms of cardiovascular risk; however, the mechanism of their interaction is not well understood.

Methods: Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) in 8 healthy men before and after an HFM preceded (16 to 18 h) by rest, a single bout of continuous moderate-intensity exercise (CME), and high-intensity interval exercise (HIIE).

Results: Before the HFM, initial brachial artery diameters were similar in all trials (0.43 +/- 0.04 cm), but after the HFM, basal diameter decreased only in the control (0.39 +/- 0.03 cm) and CME (0.38 +/- 0.04 cm) trials. Before the HFM, FMD/shear was improved by a single bout of CME (+20%, p < 0.01) and HIIE (+45%, p < 0.01; group differences, p < 0.01), with no effect in the control trial. After the HFM (30, 120, and 240 min), FMD decayed to a lesser extent with CME, but in a similar fashion to the control trial. In contrast, FMD in the HIIE trial remained elevated following the exercise despite a clear meal-induced lipemia. Although there were no correlations between vascular function and food-induced markers of cardiovascular risk, antioxidant status was strongly correlated with FMD (r = 0.9, p < 0.001).

Conclusions: These findings reveal a clinically relevant protective effect of acute exercise on the vasculature that is clearly exercise intensity dependent and tightly related to exercise-induced antioxidant capacity. (Endothelial Dysfunction Induced by Postprandial Lipemia; NCT00660491).

Figures

Figure 1. Endothelial function

A: Average peak velocity and brachial diameter during the control (no exercise), continuous moderate intensity exercise (CME), high intensity aerobic interval exercise (HIIE), and sublingual glycerol trinitrate (GTN) trials. Baseline-1 is measured before the intervention, baseline-2 16–18 hours post-intervention and immediately before the meal. Thereafter FMD/artery diameter and blood flow were measured 30min, 2 hours and 4 hours after food intake. B: Flow mediated dilatation (FMD) of the brachial artery during the experiment. C: FMD normalized for share rate. # different from baseline 1, p<0.01; * different from moderate and control, p<0.01; § different from control, p<0.01; † different from control, p<0.05; £ different from baseline, p<0.05

Figure 2. Total antioxidant status and endothelial function

A Total antioxidant status (TAS) during the control (no exercise), continuous moderate intensity exercise (CME) and high intensity aerobic interval exercise (HIIE) trials. B: Correlation between plasma total antioxidant status and flow mediated dilation in the brachial artery. # different from baseline 1, p<0.01; * different from moderate and control, p<0.01; § different from control, p<0.01; † different from control, p<0.05; £ different from baseline, p<0.05

Figure 3. Effects of acute exercise and food ingestion

A: glucose, B: C-peptide, C: Triglycerides, and D: High Density Lipoproteins. As there was no difference in these variables across trials the data have been pooled. # different from baseline 1, p<0.01; £ different from baseline, p<0.05.