Efficacy and safety of Liraglutide versus high-dose metformin as an initial treatment of type 2 diabetes; open label, randomized controlled trial

INTERVENTION: 24‐week treatment of liraglutide monotherapy 24‐week treatment of high‐dose metformin monotherapy CONDITION: Type 2 diabetes PRIMARY OUTCOME: HbA1c level after 24 weeks of treatment SECONDARY OUTCOME: Percentage of patients achieving HbA1c target <6.5% or 7.0%(JDS); Fasting plasma glucose; Body weight; Rate of hypoglycaemic episodes; Beta‐cell function (HOMA‐beta, proinsulin/insulin ratio); Bio‐markers for cardiovascular effects (PAI‐1, hsCPR, BNP); Bio‐markers for oxidative stress (8‐OH‐dG, 8‐isoprostane); Patients QOL questionnaire INCLUSION CRITERIA: 1. Patients with type 2 diabetes mellitus. 2. Informed consent obtained. 3. Age >=20 years, <75 years 4. Patients on diet/exercise therapy with or without OAD* monotherapy or combination therapy for no less than 3 months. (*OAD: alpha‐glucosidase inhibitor or biganide) 5. Patients diagnosed as type 2 diabetes mellitus in ten years. 6. HbA1c >=6.5%, <9.0%(JDS). 7. BMI >=23.5kg/m2. 8. Patients able to come to hospital/clinic every bi‐week.