Relationship between remnant cholesterol and acute kidney injury in ICU patients: insights derived from MIMIC IV.

BACKGROUND: Remnant cholesterol (RC) reflects the cholesterol content of triglyceride-rich lipoproteins, but its association with acute kidney injury (AKI) among patients in the intensive care unit (ICU) has not been adequately investigated. METHODS: We analyzed data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary outcome was incident AKI. Cox proportional hazards regression, restricted cubic spline analysis, and subgroup analyses were used to evaluate the association between RC and AKI risk in ICU patients. Kaplan-Meier curves were used to compare time to AKI across RC quartiles. RESULTS: A total of 5535 patients were included, of whom 55.66% developed AKI during their ICU stay. In the fully adjusted Cox model, the hazard ratios (HRs) for AKI in the third and fourth RC quartiles were 1.13 (95% confidence interval [CI], 1.02-1.25) and 1.19 (95% CI, 1.08-1.32), respectively, compared with the first quartile. Restricted cubic spline analysis showed no evidence of a nonlinear association between RC and AKI risk (p for nonlinearity = 0.146). Kaplan-Meier analysis further showed that patients in the highest RC quartile had the greatest cumulative incidence of AKI (log-rank p < 0.001). CONCLUSION: Elevated RC was independently associated with an increased risk of AKI during the ICU stay. Prospective and interventional studies are needed to clarify causality and determine whether RC measurement or RC-targeted management has clinical value.