Patients with end-stage renal disease (ESRD) have a higher risk than the general population of developing premature cardiovascular disease; the reasons for this are complex. Two recent randomized controlled trials in peritoneal dialysis patients have demonstrated that targeting patients to higher dialysis clearance values is not associated with a reduction in mortality. It is known that patients on peritoneal dialysis are more likely to be volume expanded, develop left ventricular hypertrophy, and have inadequate blood pressure relative to patients on hemodialysis. As a result there has been increased attention on the role of fluid management in reducing the risk of developing congestive heart failure and other adverse cardiovascular events in peritoneal dialysis patients. Extracellular fluid volume and total body water can be accurately assessed with multi-frequency bioimpedance analysis (BIA). Estimation of volume expansion by measuring the natriuretic peptide N-BNP produced by cardiac tissue in response to ventricular wall stretch can also be used.

The purpose of this study is to determine whether volume status, as measured by BIA and N-BNP levels, correlates with clinical volume assessment, cardiovascular outcomes, peritoneal membrane transport properties and markers of inflammation such as serum albumin and C-reactive protein.