Abstract: About 90% of the hyperuricemia patients are found to have renal dysfunction of uric acid excretion. Guidelines and consensus from China and foreign countries have recommend that the 24-hour uric acid excretion fraction and/or 24-hour uric acid excretion can be used for assay of renal uric acid excretion ability, clinical classification and drug selection. However, collection of a 24-hour urine sample takes a long time, and the result may not be accurate due to the possible contamination and incomplete sampling during collection and limited urine storage condition. Previous studies have found that uric acid excretion fraction in random urine sample, especially in morning urine sample, is a simple and efficient method, which may replace the 24-hour uric acid excretion method to evaluate renal uric acid excretion function and to guide clinical classification and treatment in hyperuricemia patients.

Key words: Hyperuricemia, Renal uric acid excretion, Uric acid excretion fraction, 24-hour urine, Morning urine