Effect of dwell time on carbonyl stress using icodextrin and amino acid peritoneal dialysis fluids

Background. Deterioration of the peritoneal membrane limits the technical s urvival of peritoneal dialysis (PD). Advanced glycation of the membrane has been incriminated in this evolution. Advanced glycation end products (AGEs ) develop under the influence of glucose and of its degradation products, m ainly reactive carbonyl compounds (RCOs) such as glyoxal (GO), methylglyoxa l (MGO), and 3-deoxyglucosone (3-DG). The present study was undertaken to e valuate the impact of recently developed glucose-free PD fluids on AGE gene ration. Methods. Recently developed glucose-free PD fluids containing either icodex trin or amino acids were investigated. GO, MGO, and 3-DG [high-performance liquid chromatography (HPLC)] and total RCOs (spectrophotometry) were measu red in fresh solutions and in effluents after various dwell duration. The A GE formation potential of PD fluids and effluents was assessed by incubatio n at 37 degreesC, for one week, with bovine serum albumin and by the eventu al measurement of pentosidine (HPLC) and N-epsilon-carboxymethyllysine (CML ; gas chromatography/mass spectrometry). Results. GO, MGO, and 3-DG (P < 0.001) as well as total RCOs levels (P < 0. 01) were significantly lower in icodextrin and amino acid PD fluid than in commercial, heat-sterilized, 1.36% glucose PD fluid. Pentosidine and CML ge neration were also significantly lower (P < 0.001) in icodextrin and amino acid PD fluid than in conventional 1.36% glucose PD fluid. The levels of to tal RCOs, however, increased in icodextrin and amino acid PD fluid effluent s with dwell time. AGE formation potential rose accordingly, as demonstrate d by a parallel increase in the generation of pentosidine and CML during in cubation of PD effluents. Conclusion. The present data demonstrate lower RCO contents and AGE formati on potential in fresh icodextrin and amino acid PD fluids than in fresh hea t-sterilized glucose PD fluids. However, this difference decreases progress ively during dwell time, mainly as a result of the influx of total RCOs.