The effect of choice of dialysis modality and modality switch on residual renal function in patient with stage 5 chronic kidney disease. A post hoc analysis from the ideal trial.

Abstract

Aim: To examine the effect of choice of dialysis modality and modality switch on residual renal function RRF measured by serial timed-urinary mean urea and creatinine estimation from participants enrolled in the IDEAL trial. Introduction: Although peritoneal dialysis (PD) is considered the preferred modality to preserve RRF, few studies had a head to head comparison between PD and hemodialysis (HD) and the effect of a switch in dialysis modality on RRF. Method(s): Participants who had at least two timed-urinary collections were included in this pre-defined analysis. The rate of decline of RRF was calculated from the time of dialysis commencement three monthly for 36 months, by using a mathematical model that adjusted for early or late start and RRF at dialysis commencement. Hazard ratios were used to examine its association with ethnicity, diabetes mellitus, smoking history, systolic blood pressure and use RAS blockers. Result(s): Of the 768 patients who commenced dialysis in the IDEAL study 483 patients (279 on PD and 204 on HD) were eligible. More 50% had switched dialysis modality at least once. Patients commencing on PD had a higher RRF with a mean difference of 0.71 mL/min/1.73 m2 compared to those commencing HD (P < 0.01). The higher mean difference in RRF was similarly observed when sensitive analyses were performed from randomization, when censoring the patient at modality switched, or based on planned modality (all favoring PD, P < 0.01 ). A history of smoking was a strong negative predictor of RRF. Conclusion(s): Commencing dialysis with PD confers better preservation of RRF irrespective of whether patients subsequently switched dialysis modality, compared to HD in a three year follow up period.