Kidney Week

Abstract: FR-PO079

Quantifying Change in Proteinuria after AKI among Patients with CKD 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

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

Anthony N. Muiru, MD, MPH

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

Ian Ellis McCoy, MD, MS, FASN

• 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 School of Medicine, New Orleans, Louisiana, United States

L. Lee Hamm, MD

• Chen, Jing, Tulane University School of Medicine, 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

Few studies have rigorously investigated if increased proteinuria is an important pathway by which AKI contributes to development or progression of CKD. Numerous published studies lacked appropriate non-AKI controls; Parr et al (KI 2018) relied on semiquantitative dipstick measurements obtained as part of clinical care and Hsu (JASN 2019) included only participants hospitalized shortly before enrollment. Neither study focused exclusively on patients with CKD, who are particularly vulnerable to AKI. To fill this knowledge gap, we analyzed data from the multicenter, prospective Chronic Renal Insufficiency Cohort (CRIC) study.

Methods

We analyzed CRIC study data from 7/1/2013-12/1/2021. Hospitalized AKI was defined as ≥1.5 peak to nadir inpatient serum creatinine (SCr). Mixed effects regression was applied to examine the association between AKI and natural log-transformed urine protein creatinine ratio (uPCR) ascertained at yearly CRIC research study visits. We adjusted for sex, race, clinical center as well as time-updated age, eGFR, SBP, diabetes, number of anti-hypertensive medicines, and use of ACEi or ARB.

Results

The final cohort included 3,197 participants with mean age of 65 years, 44% were female, and 42% self-identified as non-Hispanic Black. The median baseline eGFR was 52 mL/min/1.73m2 and uPCR was 0.14g/g. During a median follow-up time of 6 years, 560 patients experienced AKI and 2637 did not. Most AKI episodes were stage 1 (65%) rather than stage 2 (28%) and stage 3 (7%). We quantified a 4% increase in uPCR (relative change ratio of 1.04, [95% CI 1.02-1.06, p<0.01) after an AKI episode in the multivariable adjusted model. More severe AKI was associated with a greater change in uPCR, with stage 3 AKI being associated with a 10% increase in uPCR (relative change ratio of 1.10, [95% CI 1.02-1.19], p=0.01).

Conclusion

Episodes of AKI may result in residual structural damage to the kidneys as reflected by worsening proteinuria. However, most of the proteinuria observed among AKI survivors was already present prior to AKI.

Funding

• NIDDK Support