Abstract: Objective To investigate the predictive value of body mass index (BMI) combined with normalizing protein catabolic rate (nPCR) for identifying volume status in peritoneal dialysis (PD) patients.  Methods  This is a single-center retrospective study, patients who underwent maintenance PD treatment at the Jinling Hosptial, Nanjing University School of Medicine from March 2004 to March 2024 were included. Based on the cardiothoracic ratio (CTR), the patients were divided into normal volume group (CTR＜0.5) and volume overload group (CTR≥0.5). Relevant data were collected, and univariate analysis and binary Logistic regression analysis were used to screen the influencing factors of volume overload in PD patients. Receiver operating characteristic curve (ROC) was used to analyze the diagnostic value of BMI combined with nPCR for volume overload.  Results  A total of 2109 patients were included, including 1002 patients in the normal volume group and 1107 patients in the volume overload group. Multivariate binary logistic regression analysis showed that  nPCR (OR=0.022, 95% CI:0.011～0.046, P＜0.001), total creatinine clearance (OR= 0.988,  95% CI: 0.980～0.996, P=0.004), serum albumin (OR=0.944, 95% CI: 0.915～0.974, P＜0.001), dialysis vintage (OR=1.004, 95% CI:1.000～1.008, P=0.028), hemoglobin (OR=0.888, 95% CI:0.834～0.946, P＜ 0.001), BMI (OR=1.290, 95% CI: 1.230～1.354, P＜0.001), and urine output (OR=0.999, 95% CI: 0.999～1.000, P ＜ 0.001) were independent risk factors for volume overload in PD patients. The area under the ROC curve (AUC) showed that nPCR (AUC=0.749, 95% CI: 0.686～0.730), BMI (AUC=0.702, 95% CI: 0.680～0.724), and the combination of BMI and nPCR (AUC 0.759, 95% CI: 0.739～0.780) had statistically significant predictive value for volume overload in PD patients (P＜0.001).  Conclusion  The combination of BMI and nPCR is a good predictor of volume overload in PD patients.

Key words: Normalizing protein catabolic rate；Body mass index, Peritoneal dialysis, Volume overload