Lipid Abnormalities and Oxidized LDL in Chronic Kidney Disease Patients on Hemodialysis and Peritoneal Dialysis

Abstract

Dyslipoproteinemia and oxidative modification of low-density lipoprotein (oxLDL) contribute to the development of oxidative stress and atherosclerosis in chronic kidney disease (CKD). On the contrary, high-density lipoprotein cholesterol (HDL-C), especially HDL3-C subtype, has protective effect against oxidative damage. There is limited evidence referring HDL-C subclass levels in patients on dialysis. This study was designed to compare lipid abnormalities and oxLDL levels in hemodialysis (HD) and peritoneal dialysis (PD) patients. Serum lipids, HDL subclasses, and oxLDL were measured in 55 patients with CKD-stage 5 (31 patients on HD and 24 patients on PD) and in 21 normal controls (NC). The results showed that in dialysis patients, triglycerides were higher than in controls (p < 0.0001) and HDL-C was significantly lower (p < 0.0001). The HDL2-C subclass concentration did not differ significantly between patients and controls, while HDL3-C was lower in patients (11 ± 0.5 mg/dL) than in NC (23 ± 1, p < 0.0001). oxLDL levels were markedly increased in patients (1.92 ± 0.29 mg/L) compared to NC (0.22 ± 0.05, p < 0.0001). Patients on PD had higher levels of cholesterol (p < 0.001) and apolipoprotein B (p < 0.05) than patients on HD. However, HDL-C, HDL-C subclasses, and oxLDL concentrations did not differ significantly between PD and HD patients. It is concluded that patients with CKD have a nearly 10-fold elevation of oxLDL compared with NC. Patients on PD have differences in the lipid profile compared with patients on HD; however, both modalities seem to possess similar potential to atherosclerosis development.

Serum Thiol/Disulfide Homeostasis in Hemodialysis, Peritoneal Dialysis, and Renal Transplantation Patients

“…The disulfide/native thiol levels were also different between the three groups; the disulfide/native thiol levels were slightly higher in the transplantation and PD groups compared to the HD group. While these results are consistent with few other previous studies, increased levels of oxidative stress in HD compared to those in PD have also been reported in some studies (20)(21)(22)(23)(24). We believe that the increased oxidative stress observed in the PD patients (compared to those in the HD patients) in our study may have been caused by inflammatory responses.…”

Oxidative Dna Damage and Mortality in Hemodialysis and Peritoneal Dialysis Patients

“…The current study shows that, although the level of 8-OHdG was higher in both prevalent HD and PD patients than in control subjects, dialysis modality (and dialysis vintage) contributed to explain the variance of oxidative stress as assessed by plasma 8-OHdG. Two recent studies comparing oxidative stress in various dialysis modalities showed increased levels of advanced oxidation protein products in HD patients compared with PD patients (18,19), and three other studies found similar or lower levels of oxidative stress markers (advanced oxidation protein products, myeloperoxidase, and 8-OHdG) in HD patients than in PD patients (20)(21)(22). Although the HD procedure might induce repetitive bouts of oxidative stress, primarily through dialyzer membrane incompatibility and endotoxin contaminants (28,29), glucose degradation products in glucose-based PD fluids are also thought to increase oxidative stress (30).…”

“…Also, it is not known whether oxidative stress varies with dialysis modality. In a few studies, increased levels of oxidative stress have been reported to be associated with hemodialysis (HD) compared with peritoneal dialysis (PD) (18,19), but other studies showed the opposite results (20)(21)(22).…”

Ankyrin is the major oxidised protein in erythrocyte membranes from end-stage renal disease patients on chronic haemodialysis and oxidation is decreased by dialysis and vitamin C supplementation

“…Increased oxidative damage in patients on chronic haemodialysis treatment has been considered to contribute to their increased cardiovascular risk [47][48][49], which cannot be completely explained by traditional cardiovascular risk factors and may be ameliorated with antioxidant intervention. Despite evidence for harmful effects in the general population of high doses of some common supplements (β-carotene, vitamin E, vitamin A) [50,51], there is evidence, although limited, that chronically haemodialysed patients could benefit from the use of antioxidants to prevent cardiovascular complications [52,53].…”