Table 1 The inclusion and exclusion criteria of this study

• Age ranges from 18 to 65 years old

• Previous history of bariatric surgery

• Meet the diagnosis criteria of morbid obesity according to the WHO criteria for obesity in Asian populations [21]

• Allergic to uric acid-lowering drugs or have had previous serious adverse reactions

• Preoperative diagnosis of hyperuricemia

• No postoperative follow-up

• At least 1 gout attack in the 12 months prior to surgery

• Any history of hormone, drug or alcohol use during hospitalization and follow-up

• History of uric acid-lowering medication for at least 6 months prior to surgery