Novel Method for Osmotic Conductance to Glucose in Peritoneal Dialysis

Abstract

Introduction: The osmotic conductance to glucose (OCG) is a crucial determinant of ultrafiltration (UF) in peritoneal dialysis (PD) patients and can be used to monitor membrane integrity in patients on long-term PD. It has been proposed that OCG can be assessed based on drained volumes in 2 consecutive 1-hour glucose dwells, usually 1.5% and 4.25% glucose, in a so-called double mini-peritoneal equilibration test (dm-PET). However, recent data indicated that the dm-PET provides a poor estimate of OCG unless the residual volume (RV) is taken into account. We introduce an easy, robust, and accurate method to measure OCG and compare it with conventional methods. Methods: In a prospective cohort of 21 PD patients, a modified version of the dm-PET was performed, along with the determination of RV before, between, and after dwells. Based on computer simulations derived from the 3-pore model (TPM) for membrane permeability, we developed and validated a novel single-dwell method to estimate OCG. We next validated the equation in an independent cohort consisting of 32 PD patients. Results: Single-dwell OCG correlated more closely with actual UF (r ¼ 0.94 vs. r ¼ 0.07 for conventional dm-PET), sodium sieving, and free water transport (FWT) compared with other methods. These findings were replicated in the validation cohort in which OCG calculated using the single-dwell method closely correlated with parameters of osmotic water transport, even when RV was not taken into account, using only drained volumes. Conclusion: We propose a novel, easy, and robust single-dwell method to determine OCG in individual patients and to monitor membrane integrity over time on PD.

SGLT2 inhibition by intraperitoneal dapagliflozin mitigates peritoneal fibrosis and ultrafiltration failure in a mouse model of chronic peritoneal exposure to high-glucose dialysate

“…However, since the D/D 0 glucose ratio was not improved, the substantially reduced fibrosis may have contributed to the mitigated UF loss by improving osmotic conductance to glucose, a significant determinant of UF in PD. [30] The effluent cytokine analyses suggest a VEGF-independent mechanism of reduced peritoneal vascularization by SGLT2 inhibition and argue in favor of pathways such as modulation of angiopoietin 1/2, [31] but determination of tissue cytokine abundance may be more sensitive and valid.…”

Optimization of bimodal automated peritoneal dialysis prescription using the three-pore model

“…In contrast, the residual volume can vary greatly between dwells. For example, in a recent clinical study from our group, 16 we found that the calculation of osmotic conductance to glucose (OCG) on the basis of drained UF (i.e. drained volume À instilled volume) was uncorrelated to the actual (transmembrane) UF.…”

SGLT2 Inhibition by Intraperitoneal Dapagliflozin Mitigates Peritoneal Fibrosis and Ultrafiltration Failure in a Mouse Model of Chronic Peritoneal Exposure to High-Glucose Dialysate

“…Thus, reduced microvessel density may have contributed to mitigation of PD-induced UF loss. However, since the D/D 0 glucose ratio was not improved, the substantially reduced fibrosis may have contributed to the mitigated UF loss by improving osmotic conductance to glucose, a significant determinant of UF in PD [ 30 ]. The effluent cytokine analyses suggested a VEGF-independent mechanism of reduced peritoneal vascularization by SGLT2 inhibition and argued in favor of pathways such as modulation of angiopoietin 1/2 [ 31 ]; however, determination of tissue cytokine abundance may be more sensitive and valid.…”