Experts recommend measuring a patient’s albuminuria 3 months after hospitalization for acute kidney injury (AKI) to determine their risk for kidney disease progression, but such testing is often skipped. Could less expensive testing on a less rigid schedule provide an alternative? Yuenting Diana Kwong, MD, and colleagues examined the utility of testing total proteinuria instead.
The researchers conducted a prospective multicenter cohort study including patients from the Chronic Renal Insufficiency Cohort (CRIC) who were hospitalized with AKI between 2013 and 2021. Participants’ urine protein-to-creatinine ratio (UPCR) was measured within 1 year of hospital discharge, and the researchers used Cox proportional hazard models, focusing on c-statistics, to determine the test’s ability to distinguish risk for kidney disease progression (defined as halving of estimated glomerular filtration rate [eGFR] or end-stage kidney disease).
A CRIC cohort comprising 554 patients had their UPCR measured within 1 year of discharge after hospitalization for AKI. Of those, 82% had stage 1 AKI, 43% were female, and 51% were non-Hispanic Black. Their mean eGFR was 43 mL/min/1.73m2.
The median UPCR, measured 147 days after AKI, was 0.36 mg/g (interquartile range, 0.12-1.37 mg/g). Over a mean follow-up period of 2.6 years, 124 patients experienced kidney disease progression.
Higher post-AKI UPCR was linked to an increased risk for kidney disease progression, with a hazard ratio of 2.99 per doubling of proteinuria (95% CI, 2.54-3.52; c-statistic 0.80). A model adjusted for demographic and clinical risk factors demonstrated strong discrimination for kidney disease progression (c-statistic, 0.86). Use of renin–angiotensin system inhibitors (RASi) declined after AKI, particularly among patients with more severe AKI and lower eGFR.
The authors concluded that UPCR evaluation within 1 year after hospital discharge could be a viable alternative for assessing the kidney disease progression risk for patients after AKI. In addition, they found opportunities to enhance proteinuria management after AKI.