This is a multicentre study examining the effectiveness of angiotension converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB) or a combination of both in reducing the rate of decline in residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD) patients.

RRF has been shown to decline progressively with time on dialysis in both CAPD and hemodialysis. Although RRF is an important determinant of mortality and morbidity in peritoneal dialysis (PD) patients, few studies have addressed therapeutic approaches for preserving RRF after the initiation of dialysis therapy. Blockade of the renin-angiotensin system by ACEI or ARB is a well-established approach for renoprotection in pre-dialysis chronic kidney disease patients. Up to now, only two trials showed that an ACEI, ramipril, and ARB, valsartan , were effective in the preservation of RRF of CAPD patients. However it is important to point out that the evidence cited has limitations. First, the trial only involved patients from one university teaching hospital. Second, transport characteristics, were not assessed before the start of the study. Third, the trial was too small to detect potentially important differences in health care use and survival between groups. Therefore, whether both ACEI and ARB preserve RRF, improve clinical outcomes and decrease health care use and costs should be tested in much longer and larger studies involving multiple sites. In order to confirm these findings, here the investigators will perform prospective, randomized, open-label and multiple center study to address long-term effects of ACEI, ARB and combination of both therapy on RRF in Patients on CAPD.

Inclusion Criteria:

• All patients received CAPD more than 1 months
• Subjects of either sex, 20-75 years old
• Residual GFR of 3mL/min per 1.73 m2 or more
• With hypertension
• No history of taking an ACE inhibitor or angiotensin-receptor blockers for at least 1 month
• Provision of written informed consent by subject or guardian

Exclusion Criteria:

• Underlying medical conditions, such as congestive heart failure, or therapy with an ACE inhibitor or ARB
• Peritonitis or volume overload within the preceding 1 month
• Myocardial infarction within the preceding 6 months
• Clinically significant valvular disease
• Malignant hypertension
• History of hypertensive encephalopathy or cerebrovascular accident within the preceding 6 months
• Any condition that may have precluded a patient from remaining in the study, such as alcohol or drug abuse, chronic liver disease, malignant disease, or psychiatric disorder
• History of allergy or intolerance to an ACE inhibitor or ARB
• Participation in another clinic trial within 2 weeks prior to screening