Chronic kidney disease after acute kidney injury: a systematic review and meta-analysis

Acute kidney injury may increase the risk for chronic kidney disease and end-stage renal disease. In an attempt to summarize the literature and provide more compelling evidence, we conducted a systematic review comparing the risk for CKD, ESRD, and death in patients with and without AKI. From electronic databases, web search engines, and bibliographies, 13 cohort studies were selected, evaluating long-term renal outcomes and non-renal outcomes in patients with AKI. The pooled incidence of CKD and ESRD were 25.8 per 100 person-years and 8.6 per 100 person-years, respectively. Patients with AKI had higher risks for developing CKD (pooled adjusted hazard ratio 8.8, 95% CI 3.1-25.5), ESRD (pooled adjusted HR 3.1, 95% CI 1.9-5.0), and mortality (pooled adjusted HR 2.0, 95% CI 1.3-3.1) compared with patients without AKI. The relationship between AKI and CKD or ESRD was graded on the basis of the severity of AKI, and the effect size was dampened by decreased baseline glomerular filtration rate. Data were limited, but AKI was also independently associated with the risk for cardiovascular disease and congestive heart failure, but not with hospitalization for stroke or all-cause hospitalizations. Meta-regression did not identify any study-level factors that were associated with the risk for CKD or ESRD. Our review identifies AKI as an independent risk factor for CKD, ESRD, death, and other important non-renal outcomes.