Development of acute kidney injury (AKI) during a hospitalization is associated with an increased risk of developing chronic kidney disease (CKD) by 1 year after discharge, and the risk is influenced by the timing of AKI recovery, new findings suggest.
Michael Heung, MD, MS, of the University of Michigan in Ann Arbor, and colleagues studied 104,764 patients in the Veterans Health Administration system hospitalized in 2011 who had a baseline estimated glomerular filtration rate above 60 mL/min/1.73 m2 and no diagnosis of end-stage renal disease or non–dialysis-dependent CKD. AKI developed in 17,049 patients (16.3%), of whom 91% had stage 1 AKI, the researchers reported online ahead of print in the American Journal of Kidney Diseases.
At 1 year, CKD stage 3 or higher developed in 18.2% of the study population (31.8% and 15.5% of the CKD cases developed in the AKI and non-AKI patients, respectively). Among patients with stage 1 AKI, those with AKI that recovered in 2 days or less had a significant 43% increased relative risk of CKD stage 3 or higher by 1 year after hospital discharge. Patients with AKI that recovered in 3–10 days had a 2.0 times increased relative risk. Patients whose AKI persisted beyond 10 days had a 2.6 times increased relative risk.
“This study demonstrates the significant risk of CKD development following an episode of AKI,” the authors concluded. “This risk increases with worsening severity of AKI, as defined by duration of injury and time to recovery, and this was present with even the mildest forms of AKI with fast recovery. These results should raise awareness to the potential long-term development of CKD following AKI, the majority of which will continue to be managed by non-nephrologists.”