The relationships between post-prandial lipaemia, endothelial function andoxidative stress in healthy individuals and patients with type 2 diabetes

Post-prandial lipaemia (PPL) is a factor in atherogenesis and results in re versible endothelial dysfunction in healthy individuals. Oxidative stress a nd triglyceride (TG)-rich lipoproteins have been implicated. Type 2 diabete s (NIDDM) results in exaggerated PPL. We attempted to delineate the mechani sms of PPL induced, endothelial dysfunction (EF) and oxidative stress in 12 NIDDM and 12 matched healthy subjects. Subjects underwent a fat tolerance test, with endothelial function assessed by flow-mediated vasodilatation an d oxidative stress measured by venous lipid-derived free radicals ex vivo a nd lipid peroxidation products over the postprandial phase. Fasting TG, pos t-prandial hypertriglyceridaemia and the TG enrichment of all lipoproteins was significantly greater in NIDDM. Post-prandial endothelial function inve rsely correlated with fasting HDL-C (r = - 0.84, P = 0.0001 in both the con trol and NIDDM groups. The deterioration in EF in the NIDDM group also corr elated with TG enrichment of VLDL and LDL. PPL in both groups also resulted in increased oxidative stress. The increment in free radicals correlated w ith TG enrichment of VLDL in both groups and was, therefore, greater in NID DM, Thus, PPL - with the production of TG-enrichment of VLDL - results in e ndothelial dysfunction by an oxidative stress mechanism in both groups. The magnitude is greater in NIDDM. Fasting HDL-C appears to contribute to the protection of the endothelium against this phenomenon. Hence, exaggerated P PL associated with reduced HDL-C may be important in the pathogenesis of va scular disease, particularly in NIDDM. (C) 2001 Elsevier Science Ireland Lt d. All rights reserved.