Relationship of Uric Acid With Progression of Kidney Disease

Received 18 January 2007; accepted 16 May 2007. published online 30 June 2007.

Background

Uric acid levels are increased in patients with kidney dysfunction. We tested the hypothesis that uric acid may be associated with kidney disease progression.

Study Design

Cohort study.

Setting & Participants

5,808 participants of the Cardiovascular Health Study.

Predictor

Uric acid levels.

Outcomes & Measurements

Kidney disease progression was defined as a decrease in estimated glomerular filtration rate (GFR) of 3 mL/min/1.73 m2 per year or greater (≥0.05 mL/s) and as incident chronic kidney disease (CKD). Measures of kidney function were estimated GFR using the Modification of Diet in Renal Disease Study equation.

Results

Higher quintiles of uric acid levels were associated with greater prevalences of estimated GFR less than 60 mL/min/1.73 m2 (<1.00 mL/s) of 7%, 14%, 12%, 25%, and 42% for quintiles 1 (≤4.41 mg/dL [≤262 μmol/L]), 2 (4.41 to 5.20 mg/dL [262 to 309 μmol/L]), 3 (5.21 to 5.90 mg/dL [310 to 351 μmol/L]), 4 (5.91 to 6.90 mg/dL [352 to 410 μmol/L]), and 5 (>6.90 mg/dL [>410 μmol/L]), respectively. In comparison, there was only a modest, but significant, association between quintiles of uric acid levels and progression of kidney function decrease, with adjusted odds ratios of 1.0, 0.88 (95% confidence interval [CI], 0.64 to 1.21), 1.23 (95% CI, 0.87 to 1.75), 1.47 (95% CI, 1.04 to 2.07), and 1.49 (95% CI, 1.00 to 2.22) for quintiles 1 through 5, respectively. No significant association was found between uric acid level and incident CKD (adjusted odds ratio, 1.00; 95% CI, 0.89 to 1.14).

Limitations

Measurements of albuminuria were not available.

Conclusions

Uric acid levels are associated strongly with prevalent CKD. In comparison, greater uric acid levels had a significant, but much weaker, association with progression of kidney disease.

Index Words: Uric acid, kidney function, chronic kidney disease

1 Division of Renal Diseases and Hypertension, University of Colorado Health Sciences Center, Denver, CO

2 General Internal Medicine Section, University of California San Francisco Veterans Affairs Medical Center, San Francisco, CA

3 Collaborative Health Studies Coordinating Center, University of Washington, Seattle, WA

4 Department of Medicine, Tufts-New England Medical Center, Boston, MA

5 Department of Epidemiology, University of Pittsburgh School of Medicine, Pittsburgh, PA

6 Department of Medicine, University of Washington Cardiovascular Health Research Unit, Seattle, WA

7 Department of Epidemiology, University of Washington Cardiovascular Health Research Unit, Seattle, WA

8 Division of Nephrology, University of Washington Harborview Medical Center, Seattle, WA

9 Department of Medicine, University of Vermont, Colchester, VT

10 Veterans Affairs Pittsburgh Healthcare System, University of Pittsburgh School of Medicine, Pittsburgh, PA.

Address correspondence to Michel Chonchol, MD, Division of Renal Diseases and Hypertension, University of Colorado Health Sciences Center, Box C-281, Denver, CO 80262.

Originally published online as doi:10.1053/j.ajkd.2007.05.013 on June 28, 2007.

Because an author of this manuscript is an editor for AJKD, the peer-review and decision-making processes were handled entirely by an outside editor, Michel Jadoul, MD, Cliniques Universitaires Saint Luc, who served as acting Editor-in-Chief. Details of the journal’s procedures for potential editor conflicts are given in the Editorial Policies section of the AJKD Website.

PII: S0272-6386(07)00832-3

doi:10.1053/j.ajkd.2007.05.013

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