Association of Oxidative Stress and Technical Survival in Peritoneal Dialysis Patients

BACKGROUND: Oxidative stress has been reported to be higher in peritoneal dialysis (PD) patients than in normal subjects. The present study was conducted to test the hypothesis that oxidative stress is associated with technical survival in chronic PD patients. METHODS: We prospectively enrolled 97 chronic PD patients in a hospital-facilitated PD center. Plasma thiobarbituric acid-reactive substances (TBARS) and plasma free thiols were measured as indicators of oxidative damage to plasma lipids and of antioxidant defense. Mitochondrial DNA (mtDNA) copy number in peripheral blood leukocytes was measured as an indicator of cellular response to oxidative stress. All oxidative biomarkers were measured at the beginning of study. The observation period was 48 months and all causes of technical failure were recorded. RESULTS: During the study period, 51 patients (52.6%) continued with PD therapy, and 30 patients (30.9%) were switched to hemodialysis because of technical failure. The plasma free thiol level was identified as a significant and independent indicator of technical failure on the basis of Cox regression analysis. An increase in plasma free thiol levels was related to a decreased hazard of technical failure (hazards ratio, 0.246; 95% confidence interval, 0.083-0.728). Subjects with plasma free thiol levels lower than the median values had worse technical survival than those with plasma free thiol levels higher than the median values (log-rank test: P = 0.029). CONCLUSION: Oxidative stress is associated with technical survival in PD patients when plasma free thiol level was indicative of antioxidant defense. (Acta Nephrologica 2011; 25: 186-191)