A STUDY OF PLASMALOGEN AS AN INDEX OF OXIDATIVE STRESS IN PATIENTS WITH CHRONIC-RENAL-FAILURE - EVIDENCE OF INCREASED OXIDATIVE STRESS IN MALNOURISHED PATIENTS

Background. The incidence of premature cardiovascular disease is high in patients with chronic renal failure (CRF). Free-radical-induced tis sue damage is thought to play a major role in the pathogenesis of athe rosclerosis and several reports indicate increased oxidative stress in patients with CRF. However, the cause of such stress in CRF is not ex actly known. Plasmalogens, a group of phospholipids with a vinyl ether bond in the sn-1 position, are supposed to be sensitive markers of ox idative stress. Methods. The fasting relative plasmalogen levels of er ythrocyte membranes (DMA 16/C16:0 and DMA 18/C18:0), as well as of vit amin E and serum lipids, were determined in a cohort of 105 patients ( mean age 51+/-2 years) with advanced CRF (creatinine clearance 9+/-1 m l/min) before starting dialysis treatment. Twenty-nine healthy control s (47+/-2 years) were also investigated. Results. Significantly lower relative plasmalogen levels (DMA 16/C16:0 and DMA 18/C18:0)were found in erythrocytes of predialysis patients than in controls. When the pat ients were divided on the basis of subjective global assessment of nut ritional status (SGA), the malnourished patients (SGA 2-4) had signifi cantly (P<0.05) lower relative plasmalogen levels than the well-nouris hed predialysis patients (SGA 1). In the prospective part of the study , we found that a 12-month dialysis treatment in 38 patients was assoc iated with significant increases in both erythrocyte DMA 16/C16:0 (P<0 .001) and DMA18/C18:0 (P<0.05) ratios. Conclusion. The present results suggest that predialysis patients are exposed to an augmented oxidati ve stress which is partially reversed by 12 months of dialysis treatme nt. The present study also demonstrates lower relative plasmalogen lev els in erythrocyte membranes in malnourished than in well-nourished pr edialysis patients. One could speculate that an increased oxidative st ress may be a factor contributing to the high prevalence of cardiovasc ular disease documented in malnourished CRF patients.