Supplementary data set.

Background
Diabetic nephropathy (DN) is a serious complication of diabetes mellitus, often leading to poor outcomes in critically ill patients. Endothelial Activation and Stress Index (EASIX), a marker of endothelial dysfunction and systemic stress, has been associated with adverse outcomes in various diseases, but its role in predicting mortality in DN patients remains unclear.
Methods
A retrospective cohort study was conducted using the MIMIC-IV database. A total of 1,260 critically ill DN patients were included and stratified into tertiles based on their EASIX scores. Kaplan-Meier survival analysis, Cox proportional hazard models, and restricted cubic spline regression were applied to evaluate the association between EASIX and 30- and 60-day all-cause mortality. Subgroup analyses were also performed to assess interactions with key patient characteristics.
Results
Patients with higher EASIX scores had significantly increased ICU and in-hospital mortality rates. Cox regression analyses revealed that EASIX was an independent predictor of mortality after adjusting for age, sex, and comorbidities (HR: 1.14; 95% CI: 1.03–1.26; p = 0.01). Kaplan-Meier analysis showed significantly worse survival rates in the highest EASIX tertile. Subgroup analysis showed that higher EASIX scores were still associated with short-term survival in patients with DN in the presence of older age, male gender, and severe complications.
Conclusion
Higher EASIX scores are associated with increased short-term mortality in critically ill DN patients, highlighting its value as a prognostic biomarker for risk stratification and personalized management. Further studies are needed to validate these findings and explore therapeutic interventions targeting endothelial dysfunction.