Abstract
BACKGROUND: Chronic kidney disease (CKD) affects over 10% of the global population and is closely linked to increased cardiovascular morbidity and mortality. Mean corpuscular volume (MCV), a key hematological parameter, has been associated with various clinical outcomes. However, the relationship between MCV and mortality in CKD patients admitted to the intensive care unit (ICU) has not been thoroughly investigated, with previous studies primarily limited to single-center designs. METHODS: This retrospective multicenter cohort study analyzed data from the eICU-CRD and MIMIC-IV databases. Statistical analyses involved Kaplan-Meier survival curves and multivariable Cox proportional hazards models. Restricted cubic splines (RCS) were employed to assess the potential nonlinear relationships between MCV and mortality. RESULTS: A total of 23,724 patients were included in the analysis. Higher MCV levels were significantly associated with increased 30-day and 90-day in-hospital mortality. Kaplan-Meier analysis revealed a higher mortality risk in patients with the highest MCV levels. Cox models confirmed that MCV was a significant risk factor for mortality, with hazard ratios indicating an increased risk with each unit increase in MCV. Subgroup analyses consistently showed that elevated MCV levels were associated with a higher mortality risk across different patient groups. CONCLUSION: This first multicenter study demonstrated that elevated MCV levels are significantly associated with higher short-term mortality in CKD ICU patients, suggesting that MCV could serve as a potential biomarker for risk stratification. Future research should validate these findings and explore the underlying mechanisms.