The Mortality Risk of Acute Kidney Injury Stage 1A and 1B in Cirrhosis: A Systematic Review and Meta-Analysis

Background/Aims

Acute kidney injury (AKI) stage 1 in cirrhosis is divided into 1A and 1B, which have greatly varied prevalence in different studies. It remains controversial whether AKI stage 1A has increased mortality risk over non-acute kidney injury (NAKI), and few studies quantified the mortality risks across AKI stage 1A, 1B, and NAKI. This systematic review and meta-analysis aims to evaluate both the prevalence and mortality risks of AKI stage 1A and 1B.

Method

Pubmed, Cochrane library, EMBASE, Scopus, and Chinese National Knowledge Infrastructure databases were searched. Search terms included “acute kidney injury,” “cirrhosis,” “mortality,” and corresponding synonyms. Comparisons across AKI stage 1A, 1B, and NAKI were included. A meta-analysis was conducted to estimate the prevalence and mortality risk of AKI stage 1A and 1B in cirrhotic patients.

Results

Eleven studies were included, enrolling 2647 patients with AKI stage 1A, 3052 with stage 1B, and 1395 without AKI, which resulted into a pooled prevalence of 16.3% (95% confidence interval [CI]: 11.3-22.9%) for AKI stage 1A and 15.7% (95% CI: 9.3-25.3%) for stage 1B. Compared to NAKI, AKI stage 1A increased the mortality risk by about 2 folds (odds ratio [OR]: 1.98, 95% CI: 1.33-2.97, P = 0.004) and stage 1B increased it by 4.8 folds (OR: 4.79, 95% CI: 3.30-6.95, P < 0.001). Compared to AKI stage 1A, AKI stage 1B further increased the mortality risk by 1.6 folds (OR: 1.55, 95% CI: 1.03-2.31, P < 0.001).

Conclusion

About one in six cirrhotic patients had AKI stage 1A and 1B and both AKI stage 1A and 1B significantly increased the mortality risks of cirrhotic patients.