Figure 1: Current classification of hyperuricemia.
From: Decreased extra-renal urate excretion is a common cause of hyperuricemia
Classification of hyperuricemia is based on UUE and fractional excretion of urate (FEUA). In this study, patients were classified as overproduction hyperuricemia, when their UUE was over 25.0 mg h−1/1.73 m2 (600 mg per day/1.73 m2). Those who had FEUA under 5.5% were classified as underexcretion hyperuricemia. Combined type was classified when their UUE and FEUA met the criteria of both overproduction and underexcretion hyperuricemia. Patients who met the single criterion of overproduction hyperuricemia, excluding combined type, were defined as overproduction type. In addition to the types shown in this figure, there is a 'normal type' whose UUE is ≤25 mg h−1/1.73 m2 and FEUA is ≥5.5%. UUE unit, mg h−1/1.73 m2.
