Endothelial Dysfunction Induced by Post-Prandial Lipemia

Abstract

Objectives To study the effect of exercise and a high fat meal (HFM) on endothelial function. Background Postprandial 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 eight healthy men before and after a HFM preceded (16–18 hrs) 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) and CME (0.38±0.04) trials. Prior to 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 mins), 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). Conclusion These findings reveal a clinically relevant protective effect of acute exercise upon the vasculature that is clearly exercise intensity dependent and tightly related to exercise-induced antioxidant capacity.

Effect of repeated sprints on postprandial endothelial function and triacylglycerol concentrations in adolescent boys

“…In the present study normalised flow-mediated dilation was observed to decrease following the ingestion of the high-fat meals but, in contrast with the non-normalised findings, this decrease was not attenuated by the sprint exercise. Previous studies investigating the effect of continuous moderate-intensity and high-intensity intermittent exercise on postprandial flow-mediated dilation have reported attenuation in the postprandial decline in both flow-mediated dilation and normalised flow-mediated dilation (Sedgwick et al, 2013;Tyldum et al, 2009) but this was not the case in the present study. However, any conclusions based on the results of normalised flow-mediated dilation may need to be made cautiously, as the methods used to normalise flow-mediated dilation are currently under debate (Atkinson et al, 2009;McCully, 2012;Stoner, Tarrant, Fryer, & Faulkner, 2013).…”

“…In contrast when the adolescent boys in the present study completed the 40 maximal 6 s sprints 14 hours prior to the high-fat breakfast, postprandial endothelial dysfunction was not apparent, as there was no change in flow-mediated dilation compared to fasting. This finding is consistent with a previous study in adults that used high-intensity intermittent exercise (4 x 4 min cycle at 85 to 95% of maximum heart rate with each interspersed with 3 min cycle at 50 to 60% of maximum heart rate) which also found no evidence of endothelial dysfunction when exercise preceded consumption of a high fat meal (Tyldum et al, 2009). While exercise of a moderate intensity has also been shown to influence postprandial endothelial function in adults (Gill et al, 2003;Gill et al, 2004;Tyldum et al, 2009) and adolescents (Sedgwick et al, 2013) the beneficial effects may be more muted when the exercise intensity is moderate as these studies tended to only find an attenuation in the extent of postprandial endothelial dysfunction.…”

“…This state of endothelial dysfunction following consumption of high-fat meals has been shown previously in both adults (Gill et al, 2003;Gill et al, 2004;Tyldum et al, 2009) and adolescents (Sedgwick et al, 2013). In contrast when the adolescent boys in the present study completed the 40 maximal 6 s sprints 14 hours prior to the high-fat breakfast, postprandial endothelial dysfunction was not apparent, as there was no change in flow-mediated dilation compared to fasting.…”

“…In addition, endothelial dysfunction appears to be a requirement for the initiation and development of atherosclerosis (Juonala et al, 2004) making it a particularly pertinent risk factor to consider in the young. The ingestion of meals containing substantial quantities of fat is common in young people in western societies (Taveras et al, 2005) and ingesting large amounts of fat results in endothelial dysfunction and elevated postprandial triacylglycerol concentrations in both adults (Gill et al, 2004;Tyldum et al, 2009;Wallace, Johnson, Padilla, & Mather, 2010) and adolescents (Sedgwick et al, 2013). Therefore, interventions that reduce endothelial dysfunction or triacylglycerol concentrations postprandially could have important health benefits.…”

“…A single 30 to 180 min session of moderate-intensity exercise completed 12 to 18 h prior to the ingestion of a high-fat meal has consistently been shown to lower postprandial triacylglycerol concentrations (Barrett, Morris, Stensel, & Nevill, 2006;Barrett, Morris, Stensel, & Nevill, 2007;Gill et al, 2004;Lee, Burns, Kuk, & Arslanian, 2013;MacEneaney et al, 2009;Petitt & Cureton, 2003;Sedgwick et al, 2013;Tolfrey et al, 2008;Tolfrey et al, 2012) and more recently to attenuate postprandial endothelial dysfunction in both adults and adolescents (Gill et al, 2004;Sedgwick et al, 2013;Tyldum et al, 2009). …”