Post-prandial lipaemia and endothelial function among healthy men

Background: There is evidence that elevated post-prandial lipoproteins adversely affect progression and outcome of cardiovascular disease. Traditional risk factors are associated with impaired endothelium-mediated vasodilatation. However, studies regarding the relationship between post-prandial lipaemia and endothelial function are divergent. Methods: Twelve healthy non-smokers were included in this study. Before and after intake of a lipid cocktail rich in dairy fat, we tested endothelial-dependent (acetylcholine 0.8-160 mg/min per 100 mi forearm tissue) and -independent (sodium niuoprussid 0.6 mug/min) vascular function in the forearm vascular bed with plethysmography. Moreover, we tested the effect of l-NMMA, a competitive inhibitor of the NO synthetase, on baseline flow. Extent of post-prandial lipaemia was assessed with the increases in triglycerides and retinyl-palmitate, a marker for intestinally derived lipoproteins. Results: Baseline flow was higher after the test meal than during fasting (preprandial 6.5 +/- 0.5 ml/min* 100 mi tissue, post-prandial 8.0 +/- 0.5, p = 0.03), but similar after l-NMMA (p = 0.85). Before and after intake of the test meal, there was no significant difference in acetylcholine-induced endothelium-dependent vasodilatation (repeated measurement ANOVA, p = 0.22). At the highest acetylcholine dose, forearm Row was very similar (fasting 18.4 +/- 1.9, post-prandial 17.9 +/- 1.9, p = 0.75). At maximum acetylcholine dose, there was a weak inverse but non-significant correlation between forearm Row and post-prandial triglyceridaemia (r = -0.38, p = 0.23) and intestinally derived lipoproteins (chylomicrons r = -0.29, p = 0.35, chylomicron remnants r = -0.15, p = 0.63). However, at the lowest acetylcholine dose there was a suggestion for a positive correlation between change in flow and post-prandial lipaemia (triglyceridaemia, r = 0.53, p = 0.07; chylomicrons, r = 0.41, p = 0.18 and remnants, r = 0.51, p = 0.09). Endotheliurn-independent vasodilatation in response to sodium nitroprusside did not significantly change (p = 0.23). Conclusion: Our results suggest that among healthy men post-prandial lipaemia is not associated with a notable impairment of endothelium-mediated vascular function in forearm resistance vessels.