PLASMA-LIPIDS ARE NOT OXIDIZED DURING HEMODIALYSIS

Lipid peroxidation products, both lipid hydroperoxides and thiobarbitu ric acid reactive substances (TBARS) were determined in the plasma of 31 uremic patients treated with maintenance hemodialysis. Whereas pati ents had significantly elevated TBARS compared to 93 healthy controls (4.25+/-1.53 vs. 1.66+/-0.50 mu mol/l; p<0.01) lipid hydroperoxides we re not detected in the plasma of patients before dialysis. After hemod ialysis, a slight increase in TBARS was observed (4.50+/-1.97 mu mol/l , p>0.01). However, when the TBARS were corrected for hemoconcentratio n by relating TBARS to the plasma cholesterol concentrations a statist ically significant decrease of TBARS was observed (1.02+/-0.63 mu mol TBARS/mmol cholesterol vs. 0.84+/-0.60 mu mol TBARS/mmol cholesterol; p<0.01) after 240 min of hemodialysis. There was no evidence for the f ormation of plasma lipid hydroperoxides in the extracorporeal circulat ion. It is therefore suggested that elevated TBARS in chronic renal fa ilure are not caused by the dialysis therapy.