Protective Effect of Autologous Arteriovenous Fistulae Against Oxidative Stress in Hemodialyzed Patients

Abstract

INTRODUCTION: Oxidative stress (OS) is ubiquitous in Chronic kideney disease (CKD) and is further exacerbated by hemodialysis (HD) procedures. OS has been associated with anaemia, malnutrition, cardiovascular disease and is an independent predictor of mortality and morbidity in this group of patients (pts). Type of vascular access (VA) for HD had been strongly related with outcomes in HD pts. Prolonged use of central venous catheters for HD and arteriovenous grafts (AVG) potentially favour the development of inflammation and OS. However, the effect of VA on OS had been poorly analysed in HD pts.This study aimed to analyse the prevalence of OS in our HD pts and the effect of VA for HD related to this situation. METHODS: To assess OS status in our HD pts, we used the Oxidative Stress Index (OSI). OSI has been developed to summarise in a single value the information derived from the d-ROMs fast test and PAT analysis(H&D, Parma, Italy). The d-ROMs fast uses the concentration of hydrogen peroxide as the reference standard , and PAT uses ascorbic acid as the reference standard of Antioxidant Capacity. OSI has been formulated to indicate how far it is from the situation of normality, which is the situation of full compensation of oxidative balance. The index increase may be caused by the increase or decrease of the concentration of both peroxides and antioxidants. We studied 129 pts on Chronic HD treatment (High Flux 86,8% HDF 13,2%;DM24,5%). The population was divided according to the OSI status= Normal (N), Borderline (BL), High OSI (H) and very high OSI (VH). Patients with clinical evidence of active infection were excluded. RESULTS: 88 out of 129 pts (68%) showed altered OSI. Increased OSI was related to a significant increase in d-ROMs and PAT. We did not find out any difference in albumin, ferritin, haemoglobin, EPO or iron doses. Pts with N or BL OSI showed a significantly higher rate of autologous VA (arteriovenous fistulae(AVF)).VH OSI status was related to a higher increase in permanent tunneled central catheters (PERM) (table 1) Table1-OSI, D-ROM, PAT and rate of VA according OSI status.TRANS:Transient central venous catheter.Values expressed as average(6sd) or percent. CONCLUSIONS: In our study HD pts showed a high prevalence of OS. In this situation, the presence of AVF showed asprotectiveägainst imbalance peroxidationantioxidation.