Associations between Peritoneal Glucose Exposure, Glucose Degradation Product Exposure, and Peritoneal Membrane Transport Characteristics in Peritoneal Dialysis Patients: Secondary Analysis of the balANZ Trial

Background Glucose is the most commonly used osmotic medium in peritoneal dialysis (PD) solutions, and its use has been associated with both local and systemic adverse effects. Previous, single-center, observational cohort studies have reported conflicting findings regarding whether a relationship exists between peritoneal glucose exposure and peritoneal small solute transport rate. Methods In this secondary analysis of the balANZ multi-center, multinational, randomized controlled trial of a neutral pH, ultra-low glucose degradation product (biocompatible) versus conventional PD solutions over a 2-year period, the relationship between time varying peritoneal glucose exposure and change in peritoneal solute transport rate, (measured as dialysate to plasma creatinine ratio at 4 hours [D:PCr4h]), was evaluated using multivariable, multilevel linear regression. Baseline peritoneal glucose exposure was also assessed as either a continuous or categorical variable. Results The study included 165 patients (age 58.1 ± 14.2 years, 55% male, 33% diabetic). Peritoneal glucose exposure increased over time (coefficient 1.49, 95% confidence interval [CI] 1.07 – 1.92 and was not significantly associated with change in D:PCr4h (coefficient 0.00004, 95% CI -0.0001 – 0.0002, p = 0.68). Similar results were found when peritoneal glucose exposure was examined as a baseline continuous or categorical variable. A significant 2-way interaction was observed with PD solution type, whereby a progressive increase in D:PCr4h was seen in the patients receiving conventional PD solution, but not in those receiving biocompatible solution. Conclusions Increases in peritoneal solute transport rate in PD patients over time were not associated with peritoneal glucose exposure, although a strong and positive association with PD solution glucose degradation product content was identified. Peritoneal glucose exposure may be a less important consideration than peritoneal glucose degradation product exposure with respect to peritoneal membrane function over time.