Association Between Peritoneal Transport Changes and Arterial Stiffness Parameters in Peritoneal Dialysis Patients

Background: Alterations in peritoneal membrane transport characteristics are common in long-term peritoneal dialysis (PD) patients and may reflect underlying microvascular dysfunction. Such changes are commonly associated with peritonitis episodes, prolonged use of glucose-based dialysate, and microvascular injury to the peritoneal membrane, reflecting structural and functional deterioration of the peritoneum. Arterial stiffness, particularly measured via augmentation index (AIx) and pulse wave velocity (PWV), is a known morbidity and closely related with macro and microvascular disease in this population. However, the relationship between longitudinal changes in peritoneal transport and arterial stiffness remains unclear. Methods: This retrospective observational cohort study included all adult patients who had initiated PD and underwent a baseline peritoneal equilibration test (PET), with a follow-up duration of at least two years. AIx and PWV were measured in all participants using a non-invasive method. Patients were categorized into two groups based on the stability of their PET classification: stable PET vs. changed PET. Demographic, clinical, laboratory, and arterial stiffness parameters (PWV and AIx) were compared between groups. Results: There were no significant differences in age, sex, comorbidities, laboratory values, or dialysis and adequacy measures between the two groups. PWV values were comparable (9.3 ± 2.1 m/s vs. 9.3 ± 1.9 m/s; p = 0.90). However, the AIx was significantly higher in the changed PET group compared to the stable group (30.6 ± 10.2 vs. 23.0 ± 10.6; p = 0.02). Conclusion: The findings indicate an associative relationship between peritoneal transport changes and increased small artery stiffness. AIx may serve as a sensitive, non-invasive indicator of microvascular alterations in PD patients. These associations should be interpreted cautiously, and prospective studies are warranted to confirm the temporal and mechanistic links.