Objectives: In vitro studies of peritoneal dialysis (PD) solutions demonstrated that a lactate-buffered fluid with neutral pH and low glucose degradation products (LF) has better biocompatibility than a conventional acidic lactate-buffered fluid (CF). However, few clinical trials have evaluated the long-term benefit of the biocompatible solution on residual renal function (RRF). To compare LF with CF, we performed a prospective, randomized study with patients starting PD.
Patients and methods: After 1-month run-in period, 91 new PD patients were randomized for 12 months of treatment with either LF (Balance: Fresenius Medical Care, Bad Homburg, Germany; n = 48) or CF (Stay Safe: Fresenius; n = 43). We measured RRF, acid-base balance, peritoneal equilibration test, and adequacy of dialysis every 6 months after the run-in period.
Results: After 12 months of treatment, the residual glomerular filtration rate (GFR) in patients using LF tended to be higher than that of patients on CF (p = 0.057 by repeated-measures analysis of variance). We observed a significant difference in the changes of residual GFR between the two groups (p = 0.009), a difference that was especially marked in the subgroup whose baseline residual GFR was more than 2 mL/min/1.73 m(2). In addition, serum total CO(2) levels were higher (p = 0.001) and serum anion gap was lower (p = 0.019) in the LF group. We observed no differences between groups for Kt/V, C-reactive protein, or normalized protein equivalent of nitrogen appearance.
Conclusions: In incident PD patients with significant residual GFR, LF may better preserve RRF over a 12-month treatment period. Additionally, pH-neutral PD fluid may improve acid-base balance as compared with CF.