Quantifying Change in Proteinuria After Acute Kidney Injury Among Patients With Chronic Kidney Disease: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study
<h2>Abstract</h2><h3>Rationale & Objective</h3> Quantifying the change in proteinuria after acute kidney injury (AKI) may shed light on the pathway through which AKI contributes to kidney disease progression. <h3>Study Design</h3> Prospective cohort study of patients with chronic kidney disease (CKD) <h3>Settings & Participants</h3> 3,197 participants who were enrolled in the multicenter, prospective Chronic Renal Insufficiency Cohort (CRIC) between 7/1/2013 and 12/1/2021 <h3>Exposure</h3> AKI was defined as ≥1.5 peak to nadir inpatient serum creatinine (SCr) ascertained during a hospital admission <h3>Outcome(s)</h3> Natural log-transformed urine protein to creatinine ratio (uPCR) ascertained at annual CRIC research study visits <h3>Analytical Approach</h3> Mixed effects regression <h3>Results</h3> Among 3,197 participants, the mean age was 65 years, 44% were female, and 42% self-identified as non-Hispanic Black. The median baseline estimated glomerular filtration rate (eGFR) was 52 mL/min/1.73m<sup>2</sup> and uPCR was 0.14 g/g. 560 patients experienced 861 episodes of AKI over a median of 6 years with most being stage 1 (68%). In the multivariable model that adjusted for blood pressure and renin angiotensin system inhibitor (RASi) use, each AKI episode was associated with a 3% increase in uPCR (relative change ratio of 1.03, [95% CI 1.01-1.05, p<0.01). <h3>Limitations</h3> Hospitalized AKI with baseline CKD only, predominance of stage 1 AKI, timing of proteinuria collection was limited to annual visits, residual confounding <h3>Conclusions</h3> Among CKD patients, AKI was independently associated with worsening proteinuria (independent of changes in blood pressure or RASi use) and may reflect residual structural damage to the kidneys. However, the increase in proteinuria among patients with CKD after AKI was small.
Authors
- L. Lee Hamm
- Jesse Y. Hsu (ORCID: https://orcid.org/0000-0002-1522-6534)
- Anthony N. Muiru (ORCID: https://orcid.org/0000-0003-2622-9658)
- Mark Aaron Unruh (ORCID: https://orcid.org/0000-0002-9662-5659)
- Ian E. McCoy (ORCID: https://orcid.org/0000-0001-6470-6959)
- Xiaoming Zhang
- Debbie L. Cohen
- Hernan Rincon Choles
- Chi-yuan Hsu
- Panduranga S. Rao
- Y.Diana Kwong
- Jing Chen
- Vallabh O. Shah
- Lawrence J. Appel
- James P. Lash
- Amanda H. Anderson
- Matthew R. Weir
- Mahboob Rahman
- Laura M. Dember
- Alan S. Go
- Kathleen D. Liu
Institutions
- Tulane University (US)
- University of Maryland, Baltimore (US)
- University of Maryland Medical Center (US)
- Kaiser Permanente (US)
- University of New Mexico (US)
- University of California, San Francisco (US)
- Southwestern Medical Center (US)
- University of Pennsylvania (US)
- The University of Texas Southwestern Medical Center (US)
Publication Details
- Journal
- Kidney Medicine
- Published
- 2026-01-30
- DOI
- https://doi.org/10.1016/j.xkme.2026.101272
- Primary Topic
- Acute Kidney Injury Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Kaiser Permanente
- University of Pennsylvania
- Johns Hopkins University
- Deutsches Krebsforschungszentrum
- Georgia Clinical and Translational Science Alliance
- National Institutes of Health
- University of Illinois at Urbana-Champaign
- Perelman School of Medicine, University of Pennsylvania
- University of California, San Francisco
- Michigan Institute for Clinical and Health Research
- Clinical and Translational Science Collaborative of Cleveland, School of Medicine, Case Western Reserve University
- National Institute of Diabetes and Digestive and Kidney Diseases
- National Center for Research Resources
- National Center for Advancing Translational Sciences