Changes in urine dipstick proteinuria and risk of dialysis-requiring acute kidney injury and subsequent ESRD

Acute kidney injury (AKI) is associated with poor prognosis. Dialysis-requiring AKI and end-stage renal disease (ESRD) represents the severe form of AKI. Proteinuria is a reliable prognostic factor for kidney diseases. However, no study has investigated the association between changes in proteinuria and the risk of severe AKI. We included 2,021,548 Koreans who underwent health check-ups in 2005-2006 and 2009. Changes in proteinuria were categorized into four groups (negative: negative → negative; resolved: proteinuria ≥ 1+ → negative; incident: negative → proteinuria ≥ 1+; persistent: proteinuria ≥ 1+ → proteinuria ≥ 1+). based on urine dipstick test. Over a median follow-up of 11.84 years, we assessed adjusted hazard ratios (HRs) and 95% confidence intervals (CI) (adjusted HR [95% CI]) for incident dialysis-requiring AKI and ESRD subsequent to AKI. The risk for dialysis-requiring AKI was highest in persistent proteinuria (3.643 [2.881-4.607]), followed by incident (1.922 [1.694-2.181]), and resolved proteinuria (1.453 [1.194-1.767]), compared with negative proteinuria (reference). The risk for ESRD also increased in order of persistent (22.883 [15.067-34.755]), incident (7.508 [5.548-10.163]), resolved (4.813 [2.970-7.800]), and negative proteinuria (reference) with the magnified HR. This pattern of relationship was identically observed in participants without chronic kidney disease. All patterns of change in proteinuria were significantly associated with the increased risk of dialysis-requiring AKI and ESRD, even in resolved proteinuria. Change in proteinuria may be potential predictor for severe AKI.