Peritoneal dialysis (PD) is one of established treatments in the end stage renal disease patients. Volume overload is a predictor of mortality in PD patients. In this Randomized controlled trial, the investigators use the Body Composition Monitor (BCM), a multifrequency bioimpedance device, to measure the level of overhydration in PD patients and explore its value in fluid management in peritoneal dialysis patients as well as their prognosis.

Optimal fluid management is one of the primary objectives of dialysis treatment, and there is significant concern that peritoneal dialysis (PD) patients can become progressively fluid-loaded with time on treatment, especially as residual kidney function declines. Body Composition Monitor (BCM) has the potential to enable better management of fluid balance. The investigators undertake a prospective, randomized, open-label, controlled trial to determine whether availability of longitudinal BCM measures help clinicians maintain stable fluid status over 24 months in 300 peritoneal dialysis patients.

Inclusion Criteria:

• Patients 18 years or older but no older than 80 years.
• who had been on chronic peritoneal dialysis for more than 3 months.
• All of them have signed the informed consent.

Exclusion Criteria:

• were expected to stop PD treatment in 6 months;
• were amputees;
• had a cardiac pacemaker or metallic implants;
• had peritonitis one month before recruitment;
• treated together with hemodialysis;
• were during pregnancy or lactation;
• were positive with HIV;
• had serious diseases, including cancer, infection and liver cirrhosis, which were not suitable for the study.