A study of hospitalized persons with chronic kidney disease (CKD) fournd that acute kidney injury (AKI) did not predict worsening of kidney function trajectory once difference in pre-hospitalization characteristically were fully accounted for. Instead, the authors suggest that much of determinants of faster kidney disease decline observed after AKI may already be present before AKI. The findings are published in Annals of Internal Medicine.

Many now believe that AKI is an independent risk factor for accelerated loss of kidney function. This has led to changes in research focus, practice patterns, and public health targets. However, prior studies associating AKI with more rapid subsequent loss of kidney function had methodological limitations, including inadequate control for differences between patients who had AKI and those who did not.

Researchers from the University of California, San Francisco and colleagues in the Chronic Renal Insufficiency Cohort (CRIC study) analyzed data from 3,150 persons with CKD to determine whether AKI is independently associated with subsequent kidney function trajectory. The data showed 612 AKIs in 433 persons with CKD over a median follow-up of 3.9 years. After adjusting for patient characteristics, such as prehospitalization estimated glomerular filtration rate (eGFR) slope and level of proteinuria, AKI did not predict worsening of subsequent kidney function trajectory. Instead, the authors highlight that their results show that much of the kidney disease observed after AKI may already be present before AKI. They recommend that clinicians instead focus on flattening the eGFR slope and treating proteinuria. The authors do acknowledge that a diagnosis of AKI does present an opportunity to identify high-risk patients and implement evidence-based interventions to slow CKD progression.