Peripheral and coronary endothelial dysfunction in type 2 diabetic patients may be influenced by therapeutics. Using Radial flow monitoring and myocardial perfusion magnetic resonance imaging, we designed a controlled randomized double blind study to test the hypothesis that endothelial dysfunction will be reversed following 3 months of Metformin administration vs gliclazide. 30 patients will be included.

Inclusion Criteria:

18-70 years old, type 2 diabetes, non significant coronary atherosclerosis on inclusion coronary angiogram (ie no coronary stenosis > 70%), HbA1c<9%

Exclusion Criteria:

significant coronary stenosis (>70%), lack of informed consent, unstable hypertension, renal failure, contra-indication to metformin or gliclazide, pregnancy, atrial fibrillation, contraindication to MRI, or to adenosine, brachial artery calcifications