Allopurinol Lowers Uric Acid Levels in Adults with CKD Stage 3

New Orleans—There is an association between hyperuricemia and progression of kidney disease. Early data suggest that lowering serum uric acid in patients with kidney disease may slow progression. However, there are few data on whether lowering levels of serum uric acid improves markers of kidney damage in chronic kidney disease (CKD).

Loni J. Perrenoud and colleagues at the University of Colorado conducted a post-hoc analysis of data from a double-blind randomized placebo-controlled clinical trial that utilized allopurinol to lower serum uric acid in 80 patients with CKD stage 3. Of the 80 participants, 41 received placebo and 39 received allopurinol. The analysis was designed to examine markers of kidney damage, including urinary albumin-creatinine ratio (ACR), urinary neutrophil gelatinase-associated lipocalin (NGAL), urinary kidney injury molecule-1 (KIM-1), and urinary transforming growth factor (TGF)-b1. Urinary NGAL, KIM-1, and TGF-b1 were normalized to urinary creatinine. The Wilcoxon Two-Sample Test was applied.

Results of the analysis were reported in a poster session at Kidney Week 2017 in a poster titled The Effect of Uric Acid-Lowering via Allopurinol on Markers of Kidney Function and Damage in Stage III CKD.

At baseline, there were no significant differences between the two groups; levels of serum uric acid, estimated glomerular filtration rate estimated by CKD-EPI Equation, and urinary ACR were also similar between the placebo and allopurinol groups.

There was significant lowering of serum uric acid levels after 12 weeks of allopurinol. CKD-EPI eGFR increased by 1.79 mL/min/1.73 m2 in the allopurinol group, compared with a decline of 0.83 mL/min/1.73 m2 in the placebo group; this difference was not statistically significant, however. There were no statistically significant differences between the two groups in serum cystatin-C, cystatin-C eGFR, urinary ACR, or urinary NGAL, KIM-1, or TGF–b1.

“Allopurinol significantly lowers serum uric acid levels in adults with stage 3 CKD and may increase CKD-EPI eGFR. The mechanism behind the increased eGFR is unclear as uric acid lowering was not associated with significant change in markers of kidney damage,” the researchers said.

Source: Perrenoud LJ, Andrews E, You Z, Chonchol M, Johnson RJ, Jalal DI. The effect of uric acid-lowering via allopurinol on markers of kidney function and damage in stage III CKD. Abstract of a poster presented at the American Society of Nephrology 2017 Kidney Week, November 2, 2017, New Orleans, Louisiana.