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Abstract: TH-PO877

Association of Low-Grade Albuminuria With CKD Progression in Individuals With CKD

Session Information

Category: CKD (Non-Dialysis)

  • 2201 CKD (Non-Dialysis): Epidemiology‚ Risk Factors‚ and Prevention

Authors

  • Verma, Ashish, Boston University School of Medicine, Boston, Massachusetts, United States
  • Schmidt, Insa Marie, Boston University School of Medicine, Boston, Massachusetts, United States
  • Palsson, Ragnar, Massachusetts General Hospital, Boston, Massachusetts, United States
  • Waikar, Sushrut S., Boston University School of Medicine, Boston, Massachusetts, United States
  • Srivastava, Anand, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
Background

By convention, albuminuria, a major risk factor for CKD progression, is classified as moderately (30-300 mg/g) or severely (>300 mg/g) increased. However, the relationship of low-grade albuminuria (<30 mg/g) with CKD progression has not been well-studied among individuals with CKD.

Methods

We examined the association of urine albumin to creatinine ratio (UACR) with CKD progression (defined as eGFR decline >50% or incident ESKD) in 1629 participants with UACR <30 mg/g enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Multivariable-adjusted Cox-proportional hazard models tested the association of CKD progression with UACR modeled as a continuous variable (log base 2) and in tertiles.

Results

Mean ± SD age was 60.2 ± 9.6 years, 847 (52%) participants were women, mean eGFR was 49.6 ± 14.7 mL/min/1.73m2, and median [IQR] UACR was 6.9 [4.0, 14.2] mg/g. Over a median follow-up of 9.8 years, 182 participants developed CKD progression. In fully adjusted models, UACR had a linear association with CKD progression (Figure 1A). Each doubling of UACR was associated with 56% increased risk of CKD progression (HR 1.56, 95% Cl 1.33-1.83) (Figure 1B). Individuals in the highest tertile of UACR had a 2.64-fold increased risk of CKD progression (HR 2.64, 95% CI 1.72-4.05) compared to individuals in the lowest tertile (Figure 1B).

Conclusion

Low levels of urine albumin excretion, well below the threshold set in the current CKD staging system, were independently associated with CKD progression. Future studies are needed to determine the optimal threshold for initiation of treatment with anti-proteinuric agents and whether the further reduction in albuminuria may improve adverse clinical outcomes in individuals with CKD.

FIGURE 1: Association of UACR with CKD progression using cox-proportional hazard and cubic restricted spline models.