Comparison of Oxidative Stress and Preservation of Residual Renal Function in Incremental versus Standard Peritoneal Dialysis in Incident Patients at 2 centers of México.

Standard peritoneal dialysis (SPD) requires four daily glucose-based continues exchanges, which increase oxidative stress (OS), inflammation, and loss of residual renal function (RRF), favoring peritoneal fibrosis and technique failure. Incremental peritoneal dialysis (IPD), guided by baseline RRF, uses fewer exchanges and reduces glucose exposure. This study aimed to compare OS and RRF preservation between IPD and SPD in incident peritoneal dialysis patients. 

An open label randomized clinical trial was conducted from November 1, 2024, to April 30, 2025, at 2 centers of IMSS León, Guanajuato, Mexico. A total of 71 incident PD patients with RRF ≥ 2 mL/min and urine output ≥ 500 mL/day were randomized 37 to IPD (3 exchanges/day) or 34 to SPD (4 exchanges/day). Baseline and 6-month, measurements included inflammatory markers (CRP, ferritin, D-dimer, albumin), RRF (urine volume, glomerular filtration rate) and thiobarbituric acid reacting substances (TBARS) were measured by spectrophotometry (oxidative stress marker) only basal and at the end of following, as well as biochemical variables, including hemoglobin, glucose, triglycerides, and total cholesterol. Data were analyzed using SPSS 30 program Student’s t-test for independent and paired samples. The design and procedures of the study were approved by the Ethics Committee 1009 of IMSS and University of Guanajuato in agreement with the principles of the Declaration of Helsinki and ethical standards for human experimentation (R-2024-1009-044 and CEPIUG-P53-2024, respectively). We obtained written informed consent from all the participants before enrollment. The study was registered on ClinicalTrials.gov (Identifier: NCT07338435) and is a part of a study with following at 12 months.

A total of 71 patients were analyzed at 6 months (37 on incremental peritoneal dialysis [IPD] and 34 on standard peritoneal dialysis [SPD]). Of these, 53% initiated on IPD, 62% were male, with a mean age of 52.4 ± 12.66 years, and 58% had a diagnosis of diabetes mellitus. A significant baseline difference in age was observed, with patients in the IPD group being older. No baseline differences were found in residual renal function (RRF) or TBARS levels. Compared with SPD, IPD preserved RRF as assessed by urine volume at 6 months (1056.39 ± 505.20 vs. 882.75 ± 352.67 mL; p = 0.029). No intergroup differences were observed in inflammatory markers (C-reactive protein, ferritin, D-dimer) or in other biochemical parameters at this follow-up time point. In the intragroup analysis using paired Student’s t-test, IPD group showed a significant increase in glomerular filtration rate and hemoglobin levels, along with a significant reduction in D-dimer levels at 6 months. In the SPD group, a significant decrease in urine volume was observed, accompanied by significant increases in hemoglobin, total cholesterol, and C-reactive protein levels. No significant changes were identified in the remaining evaluated variables.

After 6 months, IPD preserved residual renal function more effectively than SPD, despite older age in the IPD group. This benefit occurred without differences in inflammatory markers between groups. IPD was associated with improved glomerular filtration rate, higher hemoglobin levels, and reduced D-dimer, whereas standard peritoneal dialysis showed loss of urine volume and increased inflammatory and metabolic markers. These findings support IPD as a safe initial dialysis strategy with renal and systemic advantages, suggesting a potential anti-inflammatory effect.