The association between serum ferritin and uric acid in humans

Objective: Urate forms a coordination complex with Fe3+ which does not support electron transport. The only enzymatic source of urate is xanthine oxidoreductase. If a major purpose of xanthine oxidoreductase is the production of urate to function as an iron chelator and antioxidant, a system for coupling the activity of this enzyme to the availability of catalytically-active metal would be required. We tested the hypothesis that there is an association between iron availability and urate production in healthy humans by correlating serum concentrations of ferritin with uric acid levels. Materials and methods: The study population included 4932 females and 4794 males in the National Health and Nutrition Examination Survey III. They were 20 years of age or older and in good health. Results: Serum concentrations of ferritin correlated positively with uric acid levels in healthy individuals (R-2 = 0.41, p < 0.001). This association was independent of an effect of gender, age, race/ethnic group, body mass, and alcohol consumption. Conclusions: The relationship between serum ferritin and uric acid predicts hyperuricemia and gout in groups with iron accumulation. This elevation in the production of uric acid with increased concentrations of iron could possibly reflect a response of the host to diminish the oxidative stress presented by available metal as the uric acid assumes the empty or loosely bound coordination sites of the iron to diminish electron transport and subsequent oxidant generation.