The impact of early statin use on the risk of acute kidney injury in septic patients in the ICU: analysis of the MIMIC-IV database

To investigate the association between early statin use and acute kidney injury (AKI) risk in septic patients admitted to the intensive care unit (ICU). This study analyzed septic patients from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were divided into AKI and non-AKI groups based on whether they developed AKI during ICU stay. AKI was defined according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The primary exposure variable was early statin use, defined as administration within the first 24 h of ICU admission. Multivariable logistic regression models were constructed to assess the association between early statin use and AKI risk, adjusting for demographic characteristics, clinical parameters, laboratory values, disease severity scores, and treatment-related factors. Subgroup analyses were performed across clinically relevant patient characteristics. Sensitivity analyses were conducted to assess the robustness of the primary findings. A total of 5102 septic patients were analyzed, with 2424 (47.51%) developing AKI during their ICU stay. Early statin therapy was administered to 1934 (37.91%) patients. The crude AKI incidence was 49.7% in the statin group and 46.1% in the non-statin group. After full adjustment for covariates, early statin use was associated with significantly lower odds of AKI (OR = 0.87, 95% CI: 0.76–0.99, P = 0.045). Among individual statins, simvastatin demonstrated the most consistent association (OR = 0.77, 95% CI: 0.62–0.95, P = 0.014). Subgroup analyses revealed that the association was observed in patients aged ≥ 60 years (OR = 0.85, 95% CI: 0.72–0.99, P = 0.042) and male patients (OR = 0.81, 95% CI: 0.68–0.96, P = 0.016), although no formal interaction tests reached statistical significance. Early statin use within 24 h of ICU admission may be associated with modestly lower odds of AKI in septic patients, with simvastatin showing the most consistent association across subgroups. Given the modest effect size, borderline statistical significance, and observational study design, these findings should be considered hypothesis-generating and require confirmation in prospective studies.