Oxidative stress in chronic renal failure patients treated by peritoneal dialysis

OBJECTIVE: To evaluate the role of oxidative stress (OS) in chronic renal failure (CRF) and the effect of peritoneal dialysis on the OS in uremic patients. Also, to investigate the role of the studied parameters of OS as early markers for the detection of peritonitis in peritoneally dialyzed patients.

METHODS: The study was conducted on 80 chronic renal failure Iraqi patients who were admitted to the dialysis centers at Al-Kadhumiya, Baghdad, Al-Yarmouk and Al-Karama teaching hospitals, Baghdad, Iraq, during the period November 1999 through to July 2000 for peritoneal or hemodialysis therapy. Their ages range between 15-75-years. This was carried out by measuring the plasma values of malondialdehyde (MDA), thiol group, albumin, uric acid and total bilirubin before and after the dialysis session, compared to age and sex matched healthy controls.

RESULTS: The significantly higher plasma MDA with lower plasma thiol levels prior to the dialysis session indicated most likely an increased OS in CRF patients, which has significantly decreased after the dialysis session. This OS was found to be significantly correlated with the degree of renal insufficiency measured by serum creatinine levels. In patients who developed peritonitis, post dialysis findings were in favor of an increase rather than a decrease in OS. Such findings were found prior to the clinical or biochemical diagnosis of peritonitis or both in most patients. Finally, in patients on regular hemodialysis therapy, results suggested a minor OS compared to patients admitted for peritoneal dialysis therapy.

CONCLUSION: Patients with CRF are subjected to an increased OS, the degree of which is related to the severity of renal failure. Moreover, plasma levels of the studied markers of OS do point in the direction of a decrease in the OS post dialysis. Such markers can be used for early detection of peritonitis in peritoneally dialyzed patients. Finally, chronic regular dialysis therapy is a more effective replacement therapy.