High body mass index is a risk factor for transition to hemodialysis or hybrid therapy and peritoneal dialysis-related infection in Japanese patients undergoing peritoneal dialysis

Purpose: Obesity may negatively impact the clinical outcomes of patients undergoing peritoneal dialysis (PD). However, the impact of obesity on PD-related outcomes remains unclear. We herein examined the association of high body mass index (BMI) with complete hemodialysis (HD) transfer, transition to HD and PD/HD hybrid therapy, peritonitis, catheter exit-site and tunnel infection (ESI/TI), and heart failure-related hospitalization. Methods: This retrospective cohort study included 120 patients who underwent PD-catheter insertion between January 2008 and June 2018. BMI ≥ 25 kg/m² at the time of PD-catheter insertion was defined as high BMI, and its association with outcomes was analyzed using the log-rank test and Cox proportional hazards models. Results: The follow-up duration was 46.2 (23.3–75.3) months. The time until transfer to HD and hybrid therapy was significantly shorter in the high BMI group than that in the low BMI group, whereas the time until HD transfer was not significantly different between the two groups (P < 0.001 and 0.18, respectively). Peritonitis-free and ESI/TI-free survivals were significantly shorter in the high BMI group than those in the low BMI group (P = 0.006 and 0.03, respectively). After adjusting for age, sex, diabetes mellitus, and estimated glomerular filtration rate, high BMI remained a significant risk factor for transferring to HD and hybrid therapy, peritonitis, and ESI/TI (hazard ratio [HR] 2.60, P < 0.001; HR 2.08, P = 0.01; HR 2.64, P = 0.02, respectively). Conclusion: BMI ≥ 25 kg/m² is a risk factor for transition to HD and hybrid therapy, peritonitis, and ESI/TI, but not for complete HD transfer in Japanese patients with PD.