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Abstract: SA-PO924

Age-Specific Racial Differences in Kidney Failure and Death Following Incident CKD Using the 2021 CKD-EPI Creatinine Equation

Session Information

Category: CKD (Non-Dialysis)

  • 2202 CKD (Non-Dialysis): Clinical‚ Outcomes‚ and Trials

Authors

  • Yan, Guofen, University of Virginia, Charlottesville, Virginia, United States
  • Nee, Robert, Walter Reed National Military Medical Center, Bethesda, Maryland, United States
  • Scialla, Julia J., University of Virginia, Charlottesville, Virginia, United States
  • Yu, Wei, University of Virginia, Charlottesville, Virginia, United States
  • Greene, Tom, University of Utah Health, Salt Lake City, Utah, United States
  • Cheung, Alfred K., University of Utah Health, Salt Lake City, Utah, United States
  • Norris, Keith C., University of California Los Angeles, Los Angeles, California, United States
Background

Recent research suggests that the 2021 CKD-EPI creatinine equation led to smaller estimated disparities in CKD outcomes (kidney failure [KF] and death) between Black and White veterans, but a greater disparity in age of CKD onset. Because the new equation changes estimated GFR (eGFR) for all adult individuals, we examined whether the recently reported racial differences in CKD outcomes based on the new equation also persisted across age groups.

Methods

The cohort included 180,881 non-Hispanic White and 32,187 non-Hispanic Black veterans, aged 18-90 years, with incident CKD from 2003-2008 in the US Veterans Health Administration, followed through 2018. Incident CKD was defined by the first time when two eGFR values at >3 months apart were both <60 mL/min/1.73 m2 using the 2021 CKD-EPI equation. For each age group, we calculated cause-specific hazard ratios (HR) of KF, censoring on death, as well as HRs of death (including death after KF) over 10 years of follow-up for Blacks versus Whites, adjusting for covariates.

Results

Upon study entry, Black and White veterans had similar mean eGFRs (50-51 mL/min/1.73 m2). However, age distribution at incident CKD differed, with 4% of White veterans being aged 18-55 years, 17% aged 56-65, 29% aged 66-75, and 50% aged 76-90, in contrast to 20%, 32%, 24% and 24% respectively in Black veterans. In the overall cohort, the adjusted risk of KF was 30% greater in Black than White veterans (Table), consistent with a recent report. This greater risk of KF was consistently seen in the younger age groups ≤75 years (31%, 36% and 26% greater risk, respectively). In the overall cohort, after adjusting for major confounding of age, along with sex, clinical factors, and comorbidities, Blacks had similar risk of death as White peers; however, this depended on age (Table).

Conclusion

The relative risk of KF and death comparing Black and White patients depends on age, which warrants greater understanding of the underlying mechanisms.

Adjusted hazard ratios (95% CIs) of CKD outcomes for Black versus White veterans by age group
 Adjusted hazard ratio (95% CI and p value) of kidney failureAdjusted hazard ratio (95% CI and p value) of death
Whole cohort1.30 (1.24-1.37)<0.00011.01 (0.99-1.03)0.28
Age 18-551.31 (1.20-1.44)<0.00010.82 (0.77-0.87)<0.0001
Age 56-651.36 (1.27-1.46)<0.00010.90 (0.87-0.94)<0.0001
Age 66-751.26 (1.13-1.40)<0.00011.01 (0.97-1.04)0.74
Age 76-900.97 (0.81-1.15)0.711.04 (1.01-1.07)0.008

Funding

  • NIDDK Support