Glucose-Lowering Effects and Safety of Adding 0.25 or 0.5 mg Duvie

Inclusion Criteria: 1. Type Ⅱ diabetes mellitus 2. Between 19 years and 80 years old 3. BMI between 20kg/㎡ to 45kg/㎡ 4. Among those using Metformin and DPP-4 inhibitor merging therapy for more than 3 months, A person who has not changed the dosage of Metformin 500 mg and DPP-4 inhibitor for more than 8 weeks at the time of screening 5. HbA1c 7.0 to 9.0 6. Agreement with written informed consent Exclusion Criteria: 1. Historical history of severe heart failure or heart failure (NYHA Class III\&IV) 2. Rapid coronary syndrome, cardiovascular interventions within 6 months 3. History of cerebral vascular diseases within six months 4. High blood pressure uncontrolled (\>160/100 mmHg) 5. In case weight loss drug is used within 3 months 6. In case of systemic corticosteroids treatment within 3 months 7. If there is an allergy or overreaction to the study drug or its components 8. In case of acute metabolic complications (ketonicemia or high osmotic pressure) within 6 months 9. Anemia Hb \< 12g/dL(male), 10g/dL(female) 10. Kidney function GFR \< 45mL/min/1.73m2 (GFR test results are calculated by the Cockcroft-Gault Calculator). 11. impaired hepatic function (AST/ALT 2.5-fold the upper limit of the normal range \[ULN\]) 12. TG\>500 mg/dL 13. LDL cholesterol \>160 mg/dL \- If a lipid-lowering agent is being taken, the existing dose should be taken during the study period. 14. The thyroid hormone is within its normal range \- however, thyroid hormone may be registered at the discretion of the investigator even if it is outside the normal range. 15. Laser treatment for proliferative retinopathy within 6 months 16. history of alcohol or drug abuse in the previous 3 months 17. history of most cancers not in remission for 5 years 18. Past history of bladder cancer 19. Women nursing or pregnant Persons who are not using effective contraceptive methods, or who refuse to use contraceptives as specified below (permitted contraceptives: condoms, castings, or implantation contraceptives, etc.) are installed with contraceptives in the uterus 20. external injury, acute infections, a history/presence of any other severe disease, or severe trauma 21. Patients who use basins - however, they can be registered by stopping 8 weeks before the start of administration of medicines for clinical trials 22. A person who has used endemic insulin for more than 7 days in the last 8 weeks 23. A person with the drug usage in the TZD series over the last eight weeks. 24. When experiencing allergies, hypersensitivity, or side effects associated with drug use in the TZD series; 25. The researcher determines that other participants may experience difficulties in participating in the test through to the end, or that participation in the test may result in additional risks or confusion in the test results.