SUSCEPTIBILITY OF VLDL TO OXIDATION IN PATIENTS ON REGULAR HEMODIALYSIS

Oxidation of VLDL in vitro increases macrophage uptake and promotes fo am cell formation, and the dyslipidaemia of chronic renal failure is c haracterised by an increase in VLDL. However, little information is av ailable with regard to the susceptibility of VLDL to oxidation in pati ents at increased risk of atherosclerosis. We have therefore assessed the composition and susceptibility to oxidation of VLDL from haemodial ysis patients anti control subjects. VLDL from haemodialysis patients contained increased lipid hydroperoxides (81.6 +/- 12.6 versus 16.1 +/ - 3.4 nmol/mg protein, P < 0.001) and malondialdehyde (35.9 +/- 7.3 ve rsus 16.0 +/- 4.1 nmol/mg protein, P < 0.05). Susceptibility to oxidat ion was increased as shown by an increased rate of propagation of the copper induced lipid peroxidation chain-reaction (11.6 +/- 1.5 x 10(-5 ) versus 7.6 +/- 1.1 x 10-(5)abs. U/min, P < 0.05) and a greater incre ase in conjugated diene formation during peroxidation (0.47 +/- 0.04 v ersus 0.25 +/- 0.03 abs. U, P<0.001). Increased VLDL peroxidation in d ialysis patients may contribute to the increased risk of cardiovascula r disease observed in this group of patients. (C) 1997 Elsevier Scienc e Ireland Ltd.