A variety of epidemiological researches culminated in the fact that patients with diabetes mellitus (DM) are at high risk of cardiovascular diseases including myocardial infarction. Recently, observational researches showed that impaired glucose tolerance (IGT) is also a risk factor for cardiovascular disease, and STOP-NIDDM study demonstrated that the treatment of IGT patients with acarbose reduced the risk of cardiovascular events as well as the progression to diabetes mellitus. However, there are no reports on the secondary prevention of anti-diabetic drugs for cardiovascular disease in IGT patients. To this end, we are conducting two clinical studies: PPAR Study and ABC Study, and the results of these studies are expected to establish the involvement of metabolic disorders in cardiovascular medicine.