A Randomized Controlled Trial of the Effects of Febuxostat Therapy on Adipokines and Markers of Kidney Fibrosis in Asymptomatic Hyperuricemic Patients With Diabetic Nephropathy

BACKGROUND: In observational studies, higher uric acid levels are associated with metabolic syndrome, diabetes, and kidney disease. OBJECTIVE: The objective of this study is to examine whether reduction of plasma uric acid with febuxostat, a xanthine oxido reductase inhibitor, impacts adipose tissue oxidative stress, adipokines, and markers of systemic inflammation or kidney fibrosis. DESIGN: This was a double-blinded randomized controlled trial. SETTING: Academic university setting was used. PATIENTS: Overweight or obese adults with hyperuricemia and type 2 diabetic nephropathy were included. MEASUREMENTS: Adipose tissue thiobarbituric acid reducing substances (TBARS) and adiponectin concentrations and urinary transforming growth factor-β (TGF-β) were primary endpoints. Plasma C-reactive protein, high molecular weight-adiponectin, interleukin-6, tumor necrosis factor-α, and TBARS and albuminuria were among predefined secondary endpoints. METHODS: Participants were randomly assigned to febuxostat (n = 40) or matching placebo (n = 40) and followed for 24 weeks. RESULTS: < .001) but had no significant effects on subcutaneous adipose tissue TBARS (-7.4%, 95% confidence interval [CI], 57.4%-101.4%) or adiponectin (6.7%, 95% CI, 26.0%-53.8%) levels or urinary TGF-β/creatinine ratio (18.0%, 95% CI, 10.0%-54.8%) or secondary endpoints. LIMITATIONS: Relatively modest sample size and short duration of follow-up. CONCLUSIONS: In this population with progressive diabetic nephropathy, febuxostat effectively reduced plasma uric acid. However, no detectable effects were observed for the prespecified primary or secondary endpoints. TRIAL REGISTRATION: The study was registered in clinicaltrials.gov (NCT01350388).