Serum Albumin-to-Phosphorus Ratio and Outcomes: The Balance Between Nutrition and Hyperphosphatemia in Peritoneal Dialysis Patients

Background The management of hyperphosphatemia in dialysis patients presents a clinical dilemma with nutritional status. This study investigated the association between serum albumin-to-phosphorus (A/P) ratio and all-cause mortality in peritoneal dialysis patients. Methods This multicenter retrospective cohort study, a total of 3,672 PD patients who met inclusion criteria from 11 Chinese PD centers from 1 July 1998 to 28 February 2023. Participants were stratified into tertiles based on A/P ratio levels. All patients were followed up until the endpoint event (all-cause death) or May 31, 2023. The clinical data of the three groups were compared, and the Kaplan-Meier method and Cox risk regression model were used to analyze the relationship between them. Results Among 3,672 participants, 2,044 (55.7%) were male, with a mean age of 50.8 ± 14.5 years and a median dialysis vintage of 56.8 (IQR 28.6–91.3) months. Based on A/P ratio tertiles, patients were categorized into: Low-level group (A/P < 0.62, n = 1,224), Medium-level group (0.62 ≤ A/P ≤ 0.82, n = 1,224), High-level group (A/P > 0.82, n = 1,224). Multivariate Cox analysis revealed the high A/P ratio was independently associated with increased all-cause mortality (HR = 1.009, 95% CI 1.0001.08-1.0172.41). The high-level group had significantly higher all-cause mortality (χ²=36.53, P < 0.001). Conclusion In patients receiving PD, an elevated serum A/P ratio is independently linked to a heightened risk of all-cause mortality.