A proSpective randomized Study comparing the effects of Empagliflozin versus sitagliptin on cardiac fat and function in patients with Type 2 diabetes (ASSET study)

INTERVENTION: Group A: Administer empagliflozin Patients in the empagliflozin group take empagliflozin 10 mg once a day orally before or after breakfast for 12 weeks. Group B: Administer sitagliptin Patients begin with sitagliptin 50 mg a day, in principle, and increase the dose to 100 mg from their observation point of the 4th week, if it is possible. They also take sitagliptin orally once a day before or after breakfast for 12 weeks. CONDITION: Type 2 Diabetes Mellitus PRIMARY OUTCOME: The changed amount and percent change from baseline of the following value are evaluated:; ; * Amount of pericardial fat INCLUSION CRITERIA: Patients who meet all of the following criteria are included in this study: 1. At the time of giving consent, T2DM patients whose HbA1c (NGS) is out of the range set by the Treatment Guide for Diabetes 2016‐2017, which is 6.0% or higher and below 10.0% even though patients have treated with 1) a dietary and exercise regimen, or 2) monotherapy of any alpha‐glucosidase inhibitor, sulphonylurea*, or glinide‐based medicine in addition to a dietary and exercise regimen, or 3) a combination therapy of any alpha‐glucosidase inhibitor and sulphonylurea* medicine, or any alpha‐glucosidase inhibitor and glinide‐based medicine in addition to a dietary and exercise regimen 2. Male and female patients who are at age of 20 years or older and younger than 75 years when giving their consent 3. Patients with BMI 22 kg/m2 or greater 4. Patients who can give their consent in a written form *Up to glimepiride 2 mg, glibenc SECONDARY OUTCOME: The changed amount and percent change from baseline of each value below are evaluated: ; ; 1. Myocardial intracellular fat amount; ; 2. Cardiac function; ; 3. Amount of fat accumulation in tissue (liver intracellular lipid content, intramyocellular and extramyocellular lipid contents); ; 4. Insulin sensitivity (in myocardium, liver, muscle, adipose tissue); ; 5. Myocardial fatty acid metabolism index (123I‐BMIPP uptake (early/first‐half image), 123I‐BMIPP uptake (latter/second‐half image), washout rate) ; ; 6. % suppression of EGP (suppression of hepatic glucose production rate); ; 7. Glucose infusion rate (GIR); ; 8. Glucose disappearance rate (Rd); ; 9. Insulin secretion index (C‐peptide, plasma insulin, HOMA‐beta); ; 10. Insulin resistance index (HOMA‐IR); ; 11. Other insulin sensitivity index (D2Glucose, glucose level, FFA); ; 12. Blood glucagon; ; 13. Energy metabolism index (calorimetric examination: amount of energy consumption, oxygen consumption and carbon dioxide emission); ; 14. Cardiac metabolism marker (renin activity, aldosterone, aldosterone/renin activity ratio, BNP, H‐FABP); ; 15. Oxidation stress marker (urinary 8OHdG); ; 16. Inflammatory marker (hsCRP); ; 17. Adipose tissue hormone index (high‐molecular weight adiponectin, leptin); ; 18. Other blood test item (quantitative albumin, HbA1c, blood glucose, TG, T‐Cho, HDL, LDL, complete blood count, Na, K, Cl, uric acid, Amy, serum creatinine, eGFR, FFA, blood ketone body, AST, ALT, gamma‐GTP, BUN, apolipoprotein); ; 19. Other urine test item (general urine test, microalbuminuria, urinary glucose, urinary ketone body, urinary Na, urinary K, urinary Cl, urinary creatinine, eGFR); ; 20. Body weight, blood pressure, heart rate, BMI, body composition (body fluid, bone mass, muscle mass, amount of fat, body fat percentage, basal metabolism quantity) ; ; 21. Chang in amount of meal consumed and the meal contents (BDHQ BOX); ; 22. Medication adherence rate (using medication adherence diary); ; 23. Occurrence rate of adverse events