Inclusion Criteria:  18-70 years old BMI>24kg/m2 Bariatric surgery patients of Beijing Friendship Hospital History of hypertension and treated with ≥2 antihypertensive drugs for more than 4 weeks No major barriers to provide written consent  Exclusion Criteria:  Secondary hypertension, except because of sleep apnea cardiovascular disease (myocardial infarction, heart failure, stroke or coronary revascularization) within 6 months Severe concomitant diseases (autoimmune disease, malignancy, late stage of liver diseases, respiratory diseases and digestive diseases) Unable to understand or comply with the study procedures