Japanese Primary Prevention of Atherosclerosis With Aspirin for Diabetes (JPAD) Trial

Inclusion Criteria: * Patients have type 2 diabetes mellitus (30 or more years old and 85 years old or less). * Patients give their informed consent to participate. Exclusion Criteria: * Patient has electrocardiographic changes, including ischemic ST-segment depression, ST-segment elevation, or pathologic Q waves. * Patient has fixed ischemic heart disease, utilizing coronary angiography. * Patient has cerebral vascular disease, including cerebral infarction, past hemorrhage, and experience of transient ischemic attack. * Patient has arteriosclerotic disease, which needs internal medicine and/or surgical medical treatment. * Patient has already taken the following anti-platelet or anti-thrombotic medicine: aspirin, ticlopidine, cilostazol, dipyridamole, trapidil, warfarin, and argatroban. * Patient has severe gastric and/or duodenal ulcer. * Patient has severe liver dysfunction. * Patient has severe renal dysfunction. * Patient has allergy for aspirin. * Patient has atrial fibrillation. * Pregnancy or the possible case of pregnancy.