Kidney Week

Abstract: FR-PO078

Value of Post-AKI Protein-to-Creatinine Ratio (PCR) in Discriminating Risk of Kidney Disease Progression: Insights from the CRIC Study

Session Information

• AKI: Epidemiology, Risk Factors, and Prevention - 2
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Kwong, Yuenting Diana, UCSF Medical Center, San Francisco, California, United States

Yuenting Diana Kwong, MD

• Liu, Kathleen D., UCSF Medical Center, San Francisco, California, United States

Kathleen D. Liu, MD, PhD, FASN

• Go, Alan S., Kaiser Permanente, Oakland, California, United States

Alan S. Go, MD

• McCoy, Ian Ellis, UCSF Medical Center, San Francisco, California, United States

Ian Ellis McCoy, MD, MS, FASN

• Muiru, Anthony N., UCSF Medical Center, San Francisco, California, United States

Anthony N. Muiru, MD, MPH

• Weir, Matthew R., University of Maryland Medical System, Baltimore, Maryland, United States

Matthew R. Weir, MD

• Unruh, Mark L., University of New Mexico Health System, Albuquerque, New Mexico, United States

Mark L. Unruh, MD, MS

• Rincon-Choles, Hernan, Cleveland Clinic, Cleveland, Ohio, United States

Hernan Rincon-Choles, MD, MS, FASN

• Hamm, L. Lee, Tulane University, New Orleans, Louisiana, United States

L. Lee Hamm, MD

• Chen, Jing, Tulane University, New Orleans, Louisiana, United States

Jing Chen, MD, MS, MSc

• Hsu, Jesse Yenchih, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Jesse Yenchih Hsu, PhD

• Zhang, Xiaoming, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Xiaoming Zhang

• Hsu, Chi-yuan, UCSF Medical Center, San Francisco, California, United States

Chi-yuan Hsu, MD, MS, MSc, FASN

Background

Proteinuria after AKI quantified by albumin-to-creatinine ratio (ACR) measured 3 months after AKI is a strong discriminator for rapid loss of kidney function (c-statistic 0.82 in Hsu JAMA 2020). Measuring proteinuria by protein-to-creatinine ratio (PCR) after AKI is less expensive and expanding the timing for collection beyond 3 months may increase flexibility in processes of care. Limited knowledge exists on the implications of using post AKI PCR collected within 1 year in discriminating risks of kidney disease progression in patients with pre-existing CKD.

Methods

We followed participants who had AKI between 7/1/2013-12/1/2021 in the Chronic Renal Insufficiency Cohort (CRIC) cohort from the time of first post AKI PCR within 1 year of AKI discharge to the primary outcome of kidney disease progression defined by halving of eGFR or progression to ESKD. Cox proportional hazards modeling was applied to evaluate the association of log-transformed post AKI proteinuria with kidney disease progression. Analysis was repeated after adjusting for demographic variables, diabetes status, BMI, eGFR, AKI stage, systolic blood pressure, and use of ACEi and ARBs.

Results

554 CRIC participants had PCR measured a median of 147 [IQR 79-233] days after AKI discharge. Their mean age was 67 years, 43% were female and 51% were non-Hispanic Black. Mean initial post AKI eGFR was 43 mL/min/1.73m² and PCR was 0.3 g/g. 82% had AKI stage 1, 15% had AKI stage 2, and 3% had AKI stage 3. Over the mean follow-up of 2.6 years, 124 had kidney disease progression. Higher post AKI PCR was associated with increased risk of kidney disease progression (hazard ratio 2.01 for each doubling of proteinuria 95% CI 1.63-2.49). Post AKI PCR was a strong discriminator of kidney disease progression (c-statistic 0.80 in the unadjusted model, 0.86 in the adjusted model with clinical risk factors). AKI severity was not associated with kidney disease progression.

Conclusion

Proteinuria evaluation by PCR obtained any time up to 1 year after AKI was independently associated with subsequent kidney disease progression in patients with CKD and may be a low cost, flexible alternative to ACR at 3 months for detecting those at risk of kidney disease progression after AKI.

Funding

• NIDDK Support