Efficacy of Metformin Versus Sitagliptin on Benign Thyroid Nodules in Type 2 Diabetes

Inclusion Criteria: * Patients with T2DM aged 18 to 65 years; * Uncomplicated T2DM, evolving for less than 3 years; * Patients with HbA1c levels between 7 and 8% (after the run-in period) * Patients with at least one TN ≥ 2 cm non-cystic, whose benignity will be confirmed by a fine-needle aspiration cytology performed twice regardless of ultrasound TIRADS score; * Naive subjects of any treatment: never received an anti-diabetic treatment OR received an anti-diabetic treatment of less than 30 days since diagnosis OR did not receive an anti-diabetic treatment during the 30 days before screening; * Patients with a creatinine clearance \> 60 ml/min; * Informed and written consent signed by the patient and the investigator; * Affiliation to the national social health system or equivalent. Exclusion Criteria: * Subjects without adequate or impaired decisional abilities for consent to research and placed under guardianship, trusteeship or safeguard of justice * Pregnant or breastfeeding woman * Woman of childbearing potential without effective contraception (estroprogestative, presentative, intrauterine device) * Suspect thyroid nodules in ultrasound (TIRADS 4 to 5) with confirmation after a fine-needle aspiration cytology; * Thyroid function abnormalities or a history of thyroid disease; * Thyroid nodules whose size or symptoms (compressive signs) require surgery * Ioduria \<100ug /L * Thyroid autoimmunity: positive anti-peroxidase, thyroglobulin or anti-TSH receptors antibodies…