Effects of Residual Renal Function on Clinical and Laboratory Features of Patients on Continuous Ambulatory Peritoneal Dialysis

Background. The contribution of residual renal function (RRF) to dialysis adequacy in continuous ambulatory peritoneal dialysis (CAPD) patients is well known. The aim of our study was to evaluate the effects of RRF on various clinical and laboratory features including degree of anemia, phosphorus control, and nutritional parameters in patients on CAPD. Methods. Patients on CAPD therapy who had undergone peritoneal and renal clearance study and had simultaneous biochemical analysis within the last 6 months were retrospectively investigated. Residual glomerular filtration rate (GFR) and biochemical measurements including hemoglobin concentration, serum albumin, cholesterol, triglycerides, calcium, phosphorus, parathormone and Creactive protein (CRP) levels were obtained and recorded. Results. Fifty-three patients (23 women, 30 men; mean age 48±15 years, range 21–77 years) receiving CAPD in our centre were analyzed. Patients were stratified into those with (n = 34) and without (n = 19) RRF. Patients with RRF had higher hemoglobin (11.2±1.9 vs. 9.9±1.7 g/dL; P = 0.022) and serum albumin levels (3.7±0.4 vs. 3.4±0.3 g/dL; P = 0.002). Among patients with RRF, residual GFR positively correlated with hemoglobin (P = 0.000) and normalized protein catabolic rate (P = 0.030), whereas negatively correlated with serum phosphorus (P = 0.020) and calcium and phosphorus product (P = 0.007). Conclusions. Our study shows the contribution of RRF in maintaining serum hemoglobin levels, as well as its impact on phosphorus balance and beneficial effect on nutritional status in CAPD patients.