The investigators designed a randomized control trial to compare the therapeutic effects of exenatide, metformin and their combination for 3 months on reproductive and metabolic improvements of overweight/obese PCOS patients with impaired glucose regulation. The investigators plan to enroll 183 patients. Inclusion criteria: 1) Patients who have PCOS which is diagnosed according to 2003 Rotterdam criteria; 2) Overweight / obesity diagnostic criteria is based on WHO-WPR; 3) IGR diagnostic criteria is based on 1999 WHO diagnostic criteria; 4) have been treated with dietary and behavioral intervention for 3 months but are ineffective; 5) have no use of other hypoglycemic drugs before 3 months of treatment.~Patients with serious complications (cardiovascular events and recent significant liver, kidney or lung disease within 3 months); high blood pressure (>160/100mmHg); active infection; secondary diabetes; pregnancy; alcohol abuse; allergic to GLP-1 receptor agonist or metformin are excluded.~Then the investigators plan to randomly divide the 183 patients into 3 groups: exenatide group, metformin group, and combination group, with 61 samples for each group. Each group use specific treatment (showed as the group name) for 3 months. Before and after the intervention, the blood samples would be collected to detect blood glucose, insulin, lipid profile, sex hormones, blood chemistry for liver and kidney function, hsCRP etc., as well as the anthropometric measurement and image examinations. All patients discontinue after 12 weeks of treatment and only routine lifestyle intervention is performed after that. All patients receive 75 g OGTT test and insulin releasing test again 12 weeks after drug withdrawal to observe the IGR remission rate. To accurately assess the insulin secretion of islet β-cell, 13 patients would be randomly selected from MET group and from EX group respectively to receive the two-step hyperglycemic clamp before the intervention and after 12-week treatment.~The investigators will compare the data and finally identify the treatment effect of exenatide on PCOS patients.
Compare the therapeutic effects of exenatide, metformin and their combination for 3 months on reproductive and metabolic improvements of overweight/obese PCOS patients with impaired glucose regulation.