Renal excretion is a cause of decreased serum uric acid during acute gout

AIMS: To evaluate the fluctuation of serum uric acid (SUA) during acute gout (AG) and explore its potential mechanisms. METHODS: Data such as SUA, urinary uric acid and 24-hour uric acid urinary excretion were collected from 126 patients diagnosed with gout and were analyzed. RESULTS: Serum uric acid was negatively correlated with age in gout patients, and significantly elevated in patients aged ≤50 years. Twenty-four-hour uric acid urinary excretion was affected by SUA, creatinine clearance, age, body mass index and urine volume. In contrast, clearance of uric acid and fractional excretion of uric acid (FEur) were more stable. SUA was significantly downregulated during acute attacks. Of the AG patients, 34.92% had detected SUA <420 μmol/L. Clearance of uric acid and FEur were notably increased in patients during acute attacks, especially in patients with SUA <420 μmol/L. CONCLUSION: This study demonstrated that the level of SUA was remarkably upregulated in young gout patients. Therefore, early onset of gout should be considered of great importance. SUA was downregulated during acute gouty arthritis, which might be associated with increased urinary excretion of uric acid.