Impacts of PIO/MET Following Short-term Intensive Insulin Treatment in Newly Diagnosed Type 2 Diabetes

Inclusion Criteria: 1. Patients with newly diagnosed type 2 diabetes who have never received any hypoglycemic treatment; 2. Fasting plasma glucose (FPG) between 7.0 mmol/l (126 mg/dl) and 16.7 mmol/l (300 mg/dl); glycosylated hemoglobin A1C\>8.5%; 3. Aged between 25 and 65 years, 4. Body mass index (BMI) 22-35 kg/m2. Exclusion Criteria: 1. Type 1 diabetes or special type of diabetes; 2. Acute diabetic complications of diabetes (DKA, HHS and lactic acidosis etc.) 3. Serious microvascular complications: proliferative stage of retinopathy; urine AER \>300 mg/g or urine protein positive, quantification \>0.5 g/d; uncontrolled painful diabetic neuropathy and significant diabetic autonomic neuropathy; 4. Severe macrovascular complications: acute cerebrovascular accident, acute coronary syndrome, vascular intervention for peripheral arterial disease or amputation requiring hospitalization within 12 months prior to enrollment; 5. Persistently increased blood pressure \>180/110 mmHg; 6. Blood creatinine clearance less than 50 ml/min, alanine aminotransferase ≥2.5×upper limit of normal, total bilirubin ≥1.5×upper limit of normal; 7. Hemoglobin \<100 g/L or need regular blood transfusion; 8. Use of drugs that may influence blood glucose within 12 weeks; 9. Systemic infection or serious concomitant disease; patients with malignancy or chronic diarrhea; 10. Uncontrolled endocrine gland dysfunction; 11. Patients with mental or communication disorders; 12. Chronic cardiac insufficiency, heart function class III and above; 13. Pregnant women, lactating women and women of child bearing age who are not willing to take contraception during the study; 14. Subjects who don't cooperate, cannot be followed up or have difficulty in completing the study considered by the investigator.