the Effects of Febuxostat Dose Tapering in Gout Patients Optimally Controlled for 5 Years or More

The goal of this clinical trial is to compare the changes in serum urate levels and symptom recurrence after reducing or suspending urate-lowering agents in well-controlled gout patients (the 'after dishes are clean' state in the Dirty Dish hypothesis) Researchers will compare three randomized groups: the reducing group takes febuxostat 20 mg once daily for 12 months, the discontinuing group takes a placebo once daily for 6 months, followed by febuxostat 20 mg once daily for the next 6 months, and the maintaining group continues their pre-study urate-lowering agents for 12 months, serving as an observational reference group. During the 12-month study period, participants will visit every 3 months for laboratory evaluations including serum urate levels, and for checking symptomatic status using questionnaires and diaries. Additionally, musculoskeletal ultrasonography and serum sample collection will be performed at baseline to study predictors for maintaining serum urate levels \<7.0 mg/dL after reducing or suspending urate-lowering therapy.