The purpose of this study is to reveal the key proteins involved in gastric bypassing surgery which may effect the decreased glucose in type 2 diabetes patietns, and evaluate standard remission rate as well as cost-benefit of gastric bypassing surgery for type 2 diabetes mellitus patients in China.

Diabetes Mellitus is a major global problem which responsibles for 4.6 million deaths each year without effective therapy methods. Recently，researchers showed that type 2 diabetes mellitus can be partly reversed by gastric bypassing surgery. However, surgeons are still not clear how to chose the proper diabetes patients for surgery as the mechanism is still not clear, and the remission rate of diabetes mellitus is not the same among different surgical procedures.

This study will enroll type 2 diabetes mellitus patients follwing Roux-en-Y gastric bypassing surgery and obese persons without type 2 diabetes surgery. The defferent expressions of serum proteins of obese persons without type 2 diabetes and type 2 diabetes patients following gastric bypassing surgery after 10 days or 3 months were detected by serum proteomics. Blood samples and urine will be taken prior to surgery, 10 days after surgery and 3 months after surgery. The long term prognosis of diabetes mellitus for 1 years and the remission rate of diabetes of patients will be evaluated.

Inclusion Criteria:

• patients diagnosed as type 2 diabetes are planning to have Roux-en-Y gastric bypass
• age:18-65yr
• HbAlc>8%

Exclusion Criteria:

• diabetes (applies for control patients)
• chronic inflammatory disease
• malignant disease
• pregnancy
• prior gastric, duodenal, proximal jejunal surgery or pancreas resection
• current use of thiazolidinediones
• treatment with incretin mimetics or DPP IV inhibitors in the prior 3 months
• HbAlc<8%
• any condition felt by the investigator to interfere with ability to complete the study

all patients are recruited from No. 150 Central Hospital of PLA