Decreased in vitro formation of AGEs with extraneal solution compared to dextrose-containing peritoneal dialysis...

Extraneal peritoneal dialysis (PD) solution (Baxter Healthcare, Deerfield, Illinois, U.S.A.) contains glucose polymer (icodextrin) as an osmotic agent in place of dextrose. We investigated the ability of Extraneal to form advanced glycation end products (AGEs) in vitro compared to standard PD solutions containing dextrose. Extraneal, Dianeal PD-2 [1.5%, 2.5%, or 4.25% dextrose (Baxter Healthcare)], or phosphate buffered saline (PBS) were incubated for 45 days with human serum albumin (HSA) or type IV collagen. AGE formation was measured by spectrofluorometry using excitation at 350 nm and emission at 430 nm. Solutions were also incubated with collagen affixed to plastic, simulating matrix collagen in the peritoneal membrane. In addition, AGE formation was assessed using icodextrin metabolites (maltose, maltotriose, and maltotetraose) at concentrations normally found in the plasma of patients treated using icodextrin. For PD solutions incubated with albumin, the relative order of AGE formation was: 4.25% dextrose > 2.5% dextrose > 1.5% dextrose > Extraneal. For incubations with collagen (in solution or affixed to plastic), AGE formation was greatest for 4.25% dextrose, intermediate for Extraneal and 2.5% dextrose, and lowest for 1.5% dextrose. Incubation of icodextrin metabolites with albumin for 45 days did not result in appreciable AGE formation. These results confirm that solutions containing icodextrin result in less in vitro AGE formation than do high dextrose solutions. The results also suggest that Extraneal may lead to improved solution biocompatibility in vivo.