Kidney Week

Abstract: PO0544

The Ratio and Difference of Urine Protein-to-Creatinine Ratio and Albumin-to-Creatinine Ratio Facilitate Risk Prediction of All-Cause Mortality: A Retrospective Cohort Study

Session Information

• CKD Clinical, Outcomes, and Trials - 1
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Chang, David R., China Medical University Hospital, Taichung, Taiwan

David R. Chang,

• Yeh, Hung chieh, China Medical University Hospital, Taichung, Taiwan

Hung chieh Yeh,

• Chu, Pei-Lun, Fu Jen Catholic University Hospital, New Taipei City, Taiwan

Pei-Lun Chu,

• Kuo, Chin-Chi, China Medical University Hospital, Taichung, Taiwan

Chin-Chi Kuo,

Background

The difference and ratio of albuminuria (defined by urine albumin-to-creatinine ratio, uACR) and proteinuria (defined by urine protein-to-creatinine ratio, uPCR) has not been systematically evaluated with relevant clinical outcomes. We aimed to assess the prognostic performance between the difference and ratio of uACR and uPCR with all-cause mortality.

Methods

This retrospective cohort study identified 2904 adult patients with concurrently measured uACR and uPCR from the same urine specimen in a tertiary medical center in Central Taiwan between January 2003 and June 2017. Urinary albumin-to-protein ratio (uAPR) was derived by dividing uACR by uPCR. Urinary non-albumin protein (uNAP) was calculated by subtracting uACR from uPCR. Conventional severity categories of uACR and uPCR were used to develop a risk matrix. We evaluated all-cause mortality based on uAPR and uNAP on a continuous scale using the multivariable Cox proportional hazards model.

Results

For each doubling increase in uPCR, uACR, and uNAP, the adjusted hazard ratios (aHRs) of all-cause mortality were 1.29 (95% confidence interval [CI]:1.24-1.35), 1.12 (1.09-1.16), and 1.41 (1.34-1.49), respectively. Linear dose-response association with all-cause mortality was only observed with uPCR and uNAP. The 3 × 3 risk matrices revealed that patients with severe proteinuria and minimal albuminuria had the highest risk of all-cause mortality (aHR 5.25, 95% CI: 1.88, 14.63). uNAP significantly improved the discriminative performance compared to that of uPCR (c-statistics: 0.834 vs. 0.828, p=0.03).

Conclusion

uNAP provides better mortality prognostic assessment than uPCR and uACR.

Hazard ratios for all-cause mortality based on uPCR, uACR, uAPR, and uNAP. Solid black lines represent aHRs based on restricted cubic splines for each urinary biomarker with knots at the 10^th, 50^th, and 90^th percentiles.

Funding

• Private Foundation Support