Complicated examinations will be repeated again after above 12 weeks treatments for both groups, including physical examination, electrocardiogram (ECG), CGMS, fasting and 2h post prandial glucose, concentration of insulin, proinsulin, C peptide, glucagon, uric acid and so on. IVGTT and hyperinsulinemic-euglycemic clamp will be repeated only for subjects who did that at the beginning of study. Data will be collected and analyzed.