Acute kidney injury incidence and mortality following spontaneous intracerebral hemorrhage: a systematic review and meta-analysis

Background: Intracerebral hemorrhage (ICH) is a neurological emergency that is frequently associated with high mortality and severe disability. Acute kidney injury (AKI) is a common in-hospital complication of ICH, and it is linked to increased mortality risk and poor functional outcomes. However, there have been inconsistent AKI diagnostic criteria across relevant studies in recent years, and there is a lack of updated comprehensive evidence regarding the association between ICH treatment and AKI risk. Therefore, this study aims to systematically investigate the incidence rate of AKI following ICH and its association with mortality in ICH patients. Methods: We conducted a comprehensive literature search in the Embase, PubMed, and Scopus databases up to April 1, 2025. Two independent reviewers performed data extraction and assessed risk of bias. The Newcastle-Ottawa Scale (NOS) was used for cohort studies, while the Risk of Bias 2 (RoB 2) tool was applied for randomized clinical trials, respectively. Results: A total of 12 studies, with a total of 16,199 patients, were included in this meta-analysis. The pooled incidence rate of AKI following ICH was 20.4% (95% confidence interval [CI]: 15.2-25.6%). Subgroup analysis based on AKI diagnostic criteria revealed that the incidence rate of AKI diagnosed by KDIGO was higher than that diagnosed by the AKIN. Further analysis of AKI stages showed that stage 1 AKI was the most common type among ICH patients, accounting for a pooled proportion of 75.6% (95% CI: 59.9-91.4%), while stages 2 and 3 AKI had similar proportions. Additionally, AKI was linked to a higher short-term mortality risk in ICH patients, with a pooled odds ratio (OR) of 3.16 (95% CI: 1.93-5.18). Conclusion: AKI is common in ICH and associated with higher short-term mortality. Future studies should focus on early AKI biomarkers, individualized blood pressure control and long-term prognosis. Systematic review registration: CRD42025642481.