Effect of Inositol Hexaphosphate (IP6) on Serum Uric Acid in Hyperuricemic Subjects: a Randomized, Double-Blind, Placebo-Controlled, Crossover Study

Inositol hexaphosphate (IP6), a food constituent with various health benefits, has been shown to suppress postprandial elevations of serum uric acid (SUA) levels in healthy adults by inhibiting purine nucleoside and base absorption. Here, we investigated the effect of repeated intake of IP6 on fasting SUA levels in hyperuricemic subjects. This randomized double-blind placebo-controlled crossover design study included 31 asymptomatic hyperuricemic subjects (fasting SUA level > 7.0 but <9.0 mg/dL). Subjects ingested placebo or IP6 drinks (600 mg twice daily) during two 2-week intervention periods with a 2-week washout period. The primary outcome was fasting SUA level; the secondary outcome was the urinary uric acid to creatinine ratio. Fasting SUA levels in the IP6 group were lower than those in the placebo group (p < 0.05). The urinary uric acid to creatinine ratio did not change between the placebo and IP6 groups (p > 0.05). This study showed that a 2-weeks supplementation period of 600 mg IP6 twice daily can improve fasting SUA levels in hyperuricemic subjects.