Cross-control Study on the Effect of Peritoneal Rest on Peritoneal Transport Function in Peritoneal Dialysis Patients

The investigators will carry out a prospective cross-over, pre-and post-controlled clinical study : 36 patients with continuous ambulatory peritoneal dialysis with high/high average transport will be recruited and treated with continuous ambulatory peritoneal dialysis and intermittent peritoneal dialysis at night (using automatic peritoneal dialysis machine) for 1 month respectively. The changes of peritoneal transport function and ultrafiltration volume before and after the two dialysis methods will be compared.

1. Inclusion Criteria

   * Continuous ambulatory peritoneal dialysis for more than 3 months;
   * The peritoneal transport function is high/high average transport (D/Pcr\>0.65 at 4 hours in the peritoneal balance test);
   * Sign the informed consent form voluntarily.
2. Exclusion Criteria

   * Patients with peritonitis in the past 3 months;
   * Patients with acute complications such as cardiovascular events, pulmonary infection and gastrointestinal bleeding in the past 3 months;
   * The doctor judged that it was not suitable for the patients in this study for other reasons.
3. Treatment plan

   The patients will be divided into two groups randomly: group A carry on continuous ambulatory peritoneal dialysis (the original dialysis plan) for 1 month, and then changed to intermittent peritoneal dialysis at night (using automatic peritoneal dialysis machine，the concentration and dosage of dialysate are consistent with the original plan) for 1 month; Group B carry on intermittent peritoneal dialysis at night (using automatic peritoneal dialysis machine，the concentration and dosage of dialysate are consistent with the original plan) for 1 month, and then change to continuous ambulatory peritoneal dialysis (original dialysis plan) for 1 month.
4. Observation indicators

Main observation indicators:

Changes in peritoneal transport rate (represented by 4-hour D/Pcr in the standard peritoneal balance test) and ultrafiltration volume (represented by 4-hour ultrafiltration volume in the standard peritoneal balance test) before and after daytime dry abdomen (intermittent peritoneal rest) and continuous peritoneal dialysis.

Secondary outcome measures:

changes in IL-1, IL-6 and TNF- α， VEGF and CTGF of the exudate in the standard peritoneal balance test before and after daytime dry abdomen (intermittent peritoneal rest) and continuous peritoneal dialysis .

Changes of body weight, blood pressure, hemoglobin, albumin, calcium, phosphorus, electrolyte, urea clearance index, etc. before and after daytime dry abdomen (intermittent peritoneal rest) and continuous peritoneal dialysis.

Eligibility Criteria:
Inclusion Criteria：

* Continuous ambulatory peritoneal dialysis for more than 3 months;
* The peritoneal transport function is high/high average transport (D/Pcr\>0.65 at 4 hours in the peritoneal balance test);
* Sign the informed consent form voluntarily.

Exclusion criteria：

* Patients with peritonitis in the past 3 months;
* Patients with acute complications such as cardiovascular events, pulmonary infection and gastrointestinal bleeding in the past 3 months;
* The doctor judged that it was not suitable for the patients in this study for other reasons.