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Abstract: FR-PO412

Age and Kidney Function Are Significantly Associated With Urine Uromodulin Levels in Children With CKD

Session Information

  • Pediatric Nephrology - I
    November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

  • 1800 Pediatric Nephrology

Authors

  • Bakhoum, Christine Y., Yale University, New Haven, Connecticut, United States
  • Matheson, Matthew, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States
  • Furth, Susan L., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Ix, Joachim H., University of California San Diego, La Jolla, California, United States
Background

Uromodulin, or Tamm-Horsfall protein, is the most abundant protein in the urine of healthy adults, and higher urine concentrations mark better tubular health. Greater kidney size and function are predictors of higher uromodulin levels in adults. Urine uromodulin has not yet been studied in children with chronic kidney disease (CKD). Here, we sought to determine the relationship between age and kidney function with urine uromodulin levels in children with CKD.

Methods

In the CKD in Children (CKiD) cohort, we utilized multivariable linear regression to evaluate the relationship of age and eGFR with urine uromodulin levels. The primary outcome was urine uromodulin concentration (Umod, mcg/ml). The secondary outcome was uromodulin indexed to urine creatinine (Umod/Cr, mg/g). Both variables were log2-transformed given skewed distribution.

Results

Among 436 participants, median [IQR] age was 12.4 years [8.9, 15.2], median eGFR was 50 ml/min/1.73 m2 [36, 62], and 27% had glomerular disease as etiology. The median Umod/Cr level was 0.118 mg/g [IQR 0.048, 0.225]. Each one-year older age was associated with 0.06 lower log2(Umod) (i.e., 4% lower Umod) and 0.18 lower log2(Umod/Cr) level (i.e., 12% lower Umod/Cr; Table 1). Each 10% lower eGFR was associated with 0.10 lower log2(Umod) (i.e., 7% lower Umod) but was not significantly associated with log2(Umod/Cr) (Table 1).

Conclusion

Among children with CKD, older age is significantly associated with lower urine uromodulin and Umod/Cr, independent of eGFR. Lower eGFR is significantly associated with lower urine uromodulin but not when it is indexed to urine creatinine. Further studies are needed to comprehensively evaluate age specific reference ranges for urine uromodulin and to evaluate the longitudinal relationship between uromodulin with both age and eGFR in children with CKD.

Funding

  • NIDDK Support