The Efficiency and Safety of Sodium Bicarbonate on Uric Acid in Patients With Asymptomatic Hyperuricemia or Gout

Inclusion Criteria: 1. Sign informed consent form; 2. Serum uric acid ≥420mmol/L; 3. Within the age range of 18-65 years old; 4. Within the BMI range of 18-30kg/m2; 5. Both men and women are eligible Exclusion Criteria: 1. General situations * Pregnancy or lactation； * Participants who can't take contraception during the study or within one month after the completion of the intervention; * Situations which will harm the participants; * Participants with bad compliance. 2. Taking part in another trail 3. Gout flares happening over the last one month; 4. Administration of medications over the last one month, including: allopurinol, Febuxostat,benzbromarone, and/or sodium bicarbonate； 5. urine pH\>7.0; 6. Hepatic function：ALT and/or AST and/or TB\>1.5 upper limit of normal (ULN); 7. Renal function：eGFR\<60 ml/min for MDRD and/or urine protein\>0.5g/24h； 8. Hypertension：\>140/90mmHg; 9. Type 2 diabetes or taking drugs for lowering glucose (not including prediabetes); 10. Urinary stone,urinary infection; 11. Taking drugs ove the last one month and during the trial, including：thiazide diuretic, Loop diuretics, pyrazinamide,ethambutol, tacrolimus, niacin, aspirin, estrogen, losartan, amlodipine, reserpine, vitamin C，fenofibrate，atorvastatin， sulfonylureas，biguanides，NSAIDs; 12. Disease which influence serum uric acid, such as cancer, lymphoma, and etc. 13. Severe disorders involving heart, liver, kidneys, brain, lungs,digestive tract, rheumatoid disease, blood, endocrine, infection, and etc; 14. Blood donation or excessive loss of blood over the last 3 month.