Statin use and acute kidney injury among hospitalized chronic kidney disease patients: a retrospective cohort study

Background Chronic kidney disease (CKD) constitutes a substantial burden in terms of cardiovascular disease and acute kidney injury (AKI). While statins are recommended for their cardiovascular benefits in CKD patients, their impact on AKI remains inconclusive. Methods A retrospective screening was conducted on all adult hospital admissions from January 1, 2018, to December 31, 2020, including patients with CKD. Statin exposure was defined as any prescription within 48 h of admission. Patients were monitored until death, discharge, or a maximum of 30 days. The primary outcome was in-hospital AKI, with in-hospital mortality as the secondary outcome. Results In a cohort of 5,376 patients, the median age was 72 years; 3,184 (59.2%) were male, and 2,129 (39.6%) were statin users. In-hospital AKI was observed in 149 (7.0%) of statin users compared to 213 (6.6%) of non-users. Statin use was significantly associated with a reduced risk of in-hospital AKI [adjusted hazard ratio [aHR], 0.74; 95% confidence interval [CI], 0.56–0.96] and in-hospital mortality (aHR, 0.45; 95% CI, 0.24–0.88). These outcomes were consistent across subgroup analyses stratified by age, gender, baseline estimated glomerular filtration rate (eGFR), and cardiovascular disease (all P for interaction >0.05), as well as in sensitivity analyses excluding patients who discontinued statin therapy during hospitalization or initiated statin therapy post-baseline. Among atorvastatin users (63.4%, 1,350/2,129), only medium-dose atorvastatin was significantly associated with reduced risk of in-hospital AKI after full adjustment (aHR, 0.68; 95% CI, 0.49–0.95). Conclusions Statin use may improve survival and reduced AKI risk in hospitalized patients with CKD, with atorvastatin showing particularly favorable renoprotective effects.