2023 Volume 47 Issue 2 Pages 141-147
Classification of hyperuricemia is important in order to understand its pathology and treat patients effectively. However, classification using 60-minute or 24-hour urine collection in outpatients is not convenient. A straightforward method has been reported for classifying the type of hyperuricemia based on the ratio of the urinary uric acid concentration to urinary creatinine concentration in spot urine. The purpose of this study was to classify hyperuricemia based on spot urine in outpatient cardiology departments and examine the treatment results of dotinurad for the uric acid underexcretion type. This study included 94 consecutive patients with hyperuricemia who had a serum uric acid level greater than 7.0 mg/dL. The patients were classified by spot urine at an outpatient cardiology department between January 2021 and November 2021. A urinary uric acid concentration to urinary creatinine concentration ratio of 0.5 or less was classified as the uric acid underexcretion type, while a ratio of more than 0.5 was classified as the uric acid overproduction type. There were 79 males and 15 females, with a mean age of 69.6 ± 11.8 years. Of the 94 patients, 63 (67%) had the uric acid underexcretion type. Drug therapy was administered to 11 patients with hyperuricemia who met the criteria for drug therapy and provided informed consent. Dotinurad was administered to 8 patients with the underexcretion type of uric acid, and 6 patients (75%) achieved the target control (serum uric acid level ≤ 6.0 mg/dL). Since only 1 mg/day of dotinurad was administered, it was deemed necessary to increase the dosage of dotinurad in order to reach the target level for controlling uric acid.
