Kidney Week

Abstract: FR-PO428

Predictors of Net Acid Excretion in the Chronic Renal Insufficiency Cohort (CRIC) Study

Session Information

• CKD: Risk Factors for Incidence and Progression - II
  November 03, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Chronic Kidney Disease (Non-Dialysis)

• 301 CKD: Risk Factors for Incidence and Progression

Authors

• Brown, Landon C., Duke University School of Medicine, Durham, North Carolina, United States

Landon C. Brown,

• Luciano, Alison, Duke University School of Medicine, Durham, North Carolina, United States

Alison Luciano,

• Pendergast, Jane F., Duke University School of Medicine, Durham, North Carolina, United States

Jane F. Pendergast,

• Khairallah, Pascale, Duke University School of Medicine, Durham, North Carolina, United States

Pascale Khairallah,

• Anderson, Cheryl A., University of California San Diego, La Jolla, California, United States

Cheryl A. Anderson,

• Sondheimer, James H., Wayne State University School of Medicine, Detroit, Michigan, United States

James H. Sondheimer,

• Hamm, L. Lee, Tulane University School of Medicine, New Orleans, Louisiana, United States

L. Lee Hamm,

• Ricardo, Ana C., University of Illinois at Chicago, Chicago, Illinois, United States

Ana C. Ricardo,

• Rao, Panduranga S., University of Michigan Health System, Ann Arbor, Michigan, United States

Panduranga S. Rao,

• Rahman, Mahboob, Case Western Reserve University, Cleveland, Ohio, United States

Mahboob Rahman,

• Miller, Edgar R., Johns Hopkins University, Baltimore, Maryland, United States

Edgar R. Miller,

• Sha, Daohang, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Daohang Sha,

• Xie, Dawei, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Dawei Xie,

• Asplin, John R., Litholink Corp, Chicago, Illinois, United States

John R. Asplin,

• Feldman, Harold I., University of Pennsylvania, Philadelphia, Pennsylvania, United States

Harold I. Feldman,

• Wolf, Myles S., Duke University School of Medicine, Durham, North Carolina, United States

Myles S. Wolf,

• Scialla, Julia J., Duke University School of Medicine, Durham, North Carolina, United States

Julia J. Scialla,

Background

In prior work, higher urine net acid excretion (NAE) was associated with lower risk of chronic kidney disease (CKD) progression in patients with diabetes. In order to (1) evaluate potential mechanisms underlying associations between NAE and outcomes, and (2) assess modifiable components for future intervention, we now evaluate independent predictors of NAE in the CRIC Study.

Methods

CRIC is a cohort of adults with entry estimated glomerular filtration rate (eGFR) of 20-70 ml/min/1.73 m². 24h NAE was measured as the sum of urine NH₄⁺ and titratable acidity in a subset, excluding those with urine pH <4 or ≥7.4 (n=20) and 2 extreme outliers (final n=978). We identified individual variables and sets of variables associated with NAE across the domains of demographics, comorbidities, laboratory measurements, diet, body composition, and medications using linear regression and domain-specific model adjusted R².

Results

Mean ± SD of NAE was 33.2 ± 17.4 mEq/day and was higher among those with diabetes (n=496) vs. without diabetes (n=482, 34.4 ± 18.7 vs. 31.9 ± 15.9 mEq/day; p=0.02). Multiple variables associated with NAE in models adjusted for age, sex, eGFR, race/ethnicity, and body surface area (Table). By domains, most variance was explained by demographics, body composition, and laboratory values including kidney function and serum bicarbonate. Among medications, several metabolically active agents including biguanides and allopurinol associated with NAE.

Conclusion

NAE relates to body composition and metabolic factors in addition to diet. This result may help explain previously observed associations between NAE and kidney outcomes in diabetes.

Funding

• NIDDK Support