 The field of secondary prevention remains an extremely important goal for diagnostic and therapeutic approaches keeping in mind that 40 of all patients with acute myocardial infarction have prediabetes, commonly as impaired glucose tolerance, which has not been known and treated and for which there are no guidelines for treatment. In this context, accumulating evidence shows beneficial effects for treating diabetes mellitus early in the course of disease, whereas other evidence shows that aggressive antidiabetic therapy may be associated with undesired risks. Accordingly, the present randomized and controlled pilot study is designed as hypothesis creating study to create first data about potential medication in early type 2 diabetes including impaired glucose tolerance of patients with known coronary artery disease as means of secondary prevention by comparing oral antidiabetic therapy with metformin with insulin glargine o.d. and by studying the respective effects on cardiovascular function and metabolism both in the fasting state and after a standardized meal. As diastolic myocardial function has emerged as important prognosticator, the hypothesis was tested that treatment with insulin glargine improves myocardial function in patients with coronary artery disease and newly diagnosed type 2 diabetes including impaired glucose tolerance. 