The influence of bicarbonate/lactate-buffered PD fluids on N{ε}-(carboxyethyl)lysine and N{ε}-(carboxymethyl)lysine in peritoneal effluent.

OBJECTIVE: Accumulation of advanced glycation end products (AGEs) may be involved in the pathogenesis of peritoneal membrane dysfunction. As glycoxidation may play an important role in AGE formation, peritoneal dialysis fluids with low levels of glucose degradation products (GDPs) might result in a reduction in AGE concentration in the peritoneal effluent. The aim of this study was to compare the effects of conventional glucose-containing dialysis solutions and low GDP level fluids on the concentration of the AGEs N(ε)-(carboxymethyl)lysine (CML) and N(ε)-(carboxyethyl)lysine (CEL) in peritoneal effluent.

DESIGN: Prospective randomized control study.

METHODS: 23 patients were treated with either conventional glucose-containing fluid (n = 11, group A) or low level GDP fluid (n = 12, group B) during a period of 12 weeks. Before and after this period, CML and CEL were measured in peritoneal effluent.

RESULTS: In groups A and B there were changes in CML concentrations [respectively 13.7 ± 17.0 and -16.0 ± 46.0 nmol/L (NS)] and CEL concentrations (respectively 20.3 ± 26.6 and -8.8 ± 18.9 nmol/L, p = 0.015). Residual renal function (RRF) in groups A and B was, respectively, 6.8 and 6.1 mL/min (NS). CML, but not CEL, in the peritoneal effluent was inversely related to RRF (r = -0.67, p < 0.05).

CONCLUSION: CEL, but not CML, in the peritoneal effluent appears to be influenced by the prescription of low GDP level fluid, probably due to the highly reduced concentration of methylglyoxal, which is needed for formation of CEL. CML is primarily influenced by RRF.