Renal Replacement Therapy: Purifying Efficiency of Automated Peritoneal Dialysis in Diabetic versus Non-Diabetic Patients

BACKGROUND In order to reduce the cardiovascular risk, morbidity and mortality of peritoneal dialysis (PD), a minimal level of small-solute clearances as well as a sodium and water balance are needed. The peritoneal dialysis solutions used in combination have reduced the complications and allow for a long-time function of the peritoneal membrane, and the preservation of residual renal function (RRF) in patients on peritoneal dialysis (PD) is crucial for the maintenance of life quality and long-term survival. This retrospective cohort study reviews our experience in automatic peritoneal dialysis (APD) patients, with end-stage renal disease (ESRD) secondary to diabetic nephropathy (DN) in comparison to non-diabetic nephropathy (NDN), using different PD solutions in combination. DESIGN Fifty-two patients, 29 diabetic and 23 non-diabetic, were included. The follow-up period was 24 months, thus serving as their own control. RESULTS The fraction of renal urea clearance (Kt) relative to distribution volume (V) (or total body water) (Kt/V), or creatinine clearance relative to the total Kt/V or creatinine clearance (CrCl) decreases according to loss of RRF. The loss of the slope of RRF is more pronounced in DN than in NDN patients, especially at baseline time interval to 12 months (loss of 0.29 mL/month vs. 0.13 mL/month, respectively), and is attenuated in the range from 12 to 24 months (loss of 0.13 mL/month vs. 0.09 mL/month, respectively). Diabetic patients also experienced a greater decrease in urine output compared to non-diabetic, starting from a higher baseline urine output. The net water balance was adequate in both groups during the follow up period. Regarding the balance sodium, no inter-group differences in sodium excretion over follow up period was observed. In addition, the removal of sodium in the urine output decreases with loss of renal function. The average concentration of glucose increase in the cycler in both groups (DN: baseline 1.44 ± 0.22, 12 months 1.63 ± 0.39, 24 months 1.73 ± 0.47; NDN: baseline 1.59 ± 0.40, 12 months 1.76 ± 0.47, 24 months 1.80 ± 0.46), in order to maintain the net water balance. The daytime dwell contribution, the fraction of day and the renal fraction of studies parameters provide sustained benefit in the follow-up time, above 30%. CONCLUSIONS The wet day and residual renal function are determinants in the achievement of the objective dose of dialysis, as well as in the water and sodium balance. The cause of chronic kidney disease (CKD) does not seem to influence the cleansing effectiveness of the technique.