Proton pump inhibitors and peritoneal dialysis-associated peritonitis: a cohort study in Newcastle, Australia.

Background: Peritoneal dialysis (PD)-associated peritonitis results in poor outcomes, including hospitalisation, PD discontinuation and death. Proton pump inhibitors (PPIs) have been linked to an increased risk of organism-specific and/or overall peritonitis in prior studies, yet they are commonly prescribed in the dialysis population.

Aims: To evaluate whether PPIs are associated with an increased risk of overall peritonitis in a local cohort.

Methods: We retrospectively identified patients with incident PD at a single Australian centre between 2012 and 2021. Baseline comorbidities, medications and PD outcomes were recorded. Patients were stratified by PPI exposure. We assessed whether PPI use affected time to first peritonitis using multivariate Cox proportional hazard modelling. The overall rate of peritonitis per patient-year was compared between groups.

Results: Of 219 patients, 94 were exposed to PPIs, of whom 40 of 94 (42.6%) developed peritonitis, compared to 56 of 125 (44.8%) of the unexposed group. PPI use was not associated with time to first peritonitis in a multivariate Cox analysis (hazard ratio 0.78 (95% confidence interval 0.51-1.18), P = 0.2). The peritonitis rate was marginally lower in the PPI group. Atherosclerotic vascular disease was associated with peritonitis in an exploratory analysis.

Conclusions: PPI use was not associated with peritonitis risk in this cohort. Further work is needed to explain the discrepant findings between studies to date, including whether PPIs modulate the risk of peritonitis caused by specific organisms.