CAPD Versus APD in Nondiabetic Peritoneal Dialysis Patients

Background: Continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) are two important PD modalities. To date, only three small sample randomized control trials(RCTs) comparing CAPD and APD have been conducted but yield inconsistent results.

Objective: Investigators plan to initiate a multicenter, prospective, randomized cross-over study to compare the quality of life and dialysis adequacy in non-diabetic PD patients.

Hypothesis:In nondiabetic peritoneal dialysis patients, APD was non-inferior to CAPD in terms of dialysis adequacy(Kt/V) and superior to CAPD in terms of quality of life(KDQOL-36 score).

Methods: This study plans to recruit 216 non-diabetic patients on maintenance peritoneal dialysis. Patients will randomly be assigned into groups A and B in a 1:1 ratio: group A receives APD from week 1 to 12 and changes to CAPD from week 13 to 24; group B receives CAPD from week 1 to 12 and changes to APD from week 13 to 24. Outcomes were evaluated at week 12 and week 24.

This multicenter, randomized, open-label, crossover trial plans to recruit non-diabetic peritoneal dialysis patients by trained investigators according to the inclusion and exclusion criteria. At the beginning of the recruitment visit, each participant is asked to provide written informed consent in compliance with the Declaration of Helsinki and the requirements of the Independent Ethics Committee, after a careful explanation of the purpose and the procedures of the trial. Instructions for manual fluid exchange and automated peritoneal dialysis machines will be provided for each eligible patient, and they will be randomly assigned (1:1) to receive 12-week treatment in group A (APD-CCPD) and group B (CAPD), followed by a subsequent switch to the other modality. Safety assessments and routine visits were performed every 4 weeks thereafter, and efficacy assessments were performed at week 12 and week 24.

For the primary efficacy outcome (the difference of Kt/V compared with baseline 3 months after treatment), the non-inferiority test shows that 172 patients could provide 80% power to detect an absolute difference of 0.27 (10% of the mean) with a common SD of 0.46 (30% of the mean) at one-sided a=0.025. For another primary outcome (the quality of life), previous studies have shown that the difference in Short Form-12 Health Survey(SF-12) physical composite summary(PCS) score between the APD and CAPD groups was approximately 6 points, and a 4-point change in PCS is considered to be clinically significant. The superiority test shows 196 patients could provide 80% power to detect an absolute difference of 6 points in mean change of PCS score between groups at one-sided a=0.025. Considering the 10% rate of loss to follow-up, the sample size of each group was finally determined to be 108 cases.

Eligibility Criteria:
Inclusion Criteria:

1. Age 18 to 75 years;
2. Maintenance peritoneal dialysis for ≥ 1 month;
3. Weekly total CrCL ≥ 45 liters/week/1.73m2 body surface area;
4. Total weekly Kt/V ≥ 1.7.

Exclusion Criteria:

1. Patients with diabetes mellitus;
2. Maintained peritoneal dialysis solution with a glucose concentration \>2.5%;
3. Combined with acute events of cardiovascular disease(CVD), cardiac function ≥ New York Heart Association (NYHA) class III;
4. Episodes of peritonitis in the past 1 month;
5. Abdominal surgery other than PD catheter insertion in the past 3 months;
6. Planned kidney transplant in the last 6 months;
7. Active hepatitis, cirrhosis, psychiatric disease, malignancy, pregnancy.