Joint effects of diabetes and time-weighted average multidimensional nutritional indices on mortality in patients undergoing peritoneal dialysis: a landmark analysis.

Background: Diabetes and malnutrition are critical prognostic indicators for individuals undergoing peritoneal dialysis (PD). Nevertheless, prior research has predominantly focused on initial nutritional assessments, which may not adequately reflect the cumulative burden of long-term nutritional exposure. Consequently, the combined influence of diabetes and longitudinal nutritional changes on mortality risk remains largely unexplored. Methods: This study retrospectively collected longitudinal follow-up data from patients who underwent PD at the Second Hospital of Jilin University between January 2016 and July 2024, with follow-up continued until July 30, 2025. Utilizing a landmark analysis framework, longitudinal nutritional status was evaluated through Time-Weighted Average (TWA) multidimensional nutritional indices. These indices included the TWA-Controlling Nutritional Status (CONUT) score, TWA-Prognostic Nutritional Index (PNI), and TWA-hemoglobin, albumin, lymphocyte, and platelet (HALP) score. Cox proportional hazards models were employed to determine the associations between diabetes status, longitudinal nutritional indices, and their joint effects with both all-cause and cardiovascular mortality. Furthermore, interaction analyses and restricted cubic spline models were applied to ascertain whether diabetes modulated the relationship between longitudinal nutritional status and mortality risk. Results: The study cohort comprised 229 patients undergoing PD, with an average age of 48.68 ± 13.42 years; 87 of these patients had diabetes. Among the longitudinal nutritional indices evaluated, the TWA-CONUT score demonstrated the highest predictive accuracy for both all-cause and cardiovascular mortality. Both diabetes and a poorer long-term nutritional status were independently linked to an elevated risk of death. Patients presenting with both diabetes and malnutrition experienced substantially higher risks of all-cause mortality and cardiovascular mortality, with HRs of 5.10 (95% CI, 2.08-12.48) and 6.86 (95% CI, 1.93-24.32), respectively. A statistically significant interaction was observed between diabetes status and the TWA-CONUT score concerning all-cause mortality ( Conclusion: The integration of the TWA-CONUT score with diabetes status holds potential for identifying PD patients at an elevated risk of mortality. Specifically, individuals with both diabetes and chronic malnutrition faced significantly increased risks of all-cause and cardiovascular mortality.