Original Paper

Electronegative LDL and Lipid Abnormalities in Patients Undergoing Hemodialysis and Peritoneal Dialysis
J. Lobo^a, F. Santos^b, D. Grosso^a, R. Lima^{b, c}, A.L. Barreira^{b, c}, M. Leite, Jr.^{b, c}, D. Mafra^d, D.S.P. Abdalla<sup>a

a</sup>University of São Paulo, School of Pharmaceutical Sciences, São Paulo, and
^bDivision of Nephrology, Federal University of Rio de Janeiro,
^cCentro Integrado de Nefrologia, and
^dDepartment of Clinical Nutrition, Federal Fluminense University, Rio de Janeiro, Brazil

Address of Corresponding Author

Nephron Clin Pract 2008;108:c298-c304 (DOI: 10.1159/000127982)

  Key Words

• Hemodialysis
• Peritoneal dialysis
• Electronegative low-density lipoprotein
• Cardiovascular disease

  Abstract

Background: Oxidative modification of low-density lipoprotein (LDL) has been demonstrated in patients with end-stage renal disease, where it is associated with oxidative stress and plays a key role in the pathogenesis of atherosclerosis. In this context, the generation of minimally oxidized LDL, also called electronegative LDL [LDL(-)], has been associated with active disease, and is a detectable sign of atherogenic tendencies. The purpose of this study was to evaluate serum LDL(-) levels and anti-LDL(-) IgG autoantibodies in end-stage renal disease patients on dialysis, comparing patients on hemodialysis (HD), peritoneal dialysis (PD) and a control group. In addition, the serum lipid profile, nutritional status, biochemical data and parameters of mineral metabolism were also evaluated. Methods: The serum levels of LDL(-) and anti-LDL(-) IgG autoantibodies were measured in 25 patients undergoing HD and 11 patients undergoing PD at the Centro Integrado de Nefrologia, Rio de Janeiro, Brazil. Ten healthy subjects served as a control group. Serum levels of albumin, total cholesterol, triglycerides and lipoproteins were measured. Calculations of subjects' body mass index and measurements of waist circumference, triceps skin fold and arm muscle area were performed. Measurements of hematocrit, serum blood urea nitrogen, creatinine, parathyroid hormone, phosphorus and calcium were taken. Results: Levels of LDL(-) were higher in HD patients (575.6 ± 233.1 µg/ml) as compared to PD patients (223.4 ± 117.5 µg/ml, p < 0.05), which in turn were higher than in the control group (54.9 ± 33.3 µg/ml, p < 0.01). The anti-LDL(-) IgG autoantibodies were increased in controls (0.36 ± 0.09 µg/ml) as compared to PD (0.28 ± 0.12 µg/ml, p < 0.001) and HD patients (0.2 ± 0.1 µg/ml, p < 0.001). The mean values of total cholesterol and LDL were considered high in the PD group, whereas the mean triceps skin fold was significantly lower in the HD group. Conclusion: Levels of LDL(-) are higher in renal patients on dialysis than in normal individuals, and are reciprocally related to IgG autoantibodies. LDL(-) may be a useful marker of oxidative stress, and this study suggests that HD patients are more susceptible to cardiovascular risk due to this condition. Moreover, autoantibodies reactive to LDL(-) may have protective effects in chronic kidney disease.

Copyright © 2008 S. Karger AG, Basel

  Author Contacts

Maurilo Leite, Jr., MD
Federal University of Rio de Janeiro
R. Min. Otavio Kelly 296, 302
Niterói, 24220-301, Rio de Janeiro (Brazil) Tel. +55 21 2562 2669, Fax +55 21 3332 8648, E-Mail mleitejr@hucff.ufrj.br

  Article Information

Received: May 1, 2007
Accepted: December 28, 2007
Published online: April 24, 2008
Number of Print Pages : 7
Number of Figures : 3, Number of Tables : 2, Number of References : 45