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.

This is a single centre, short term (24 weeks), therapy controlled and randomized prospective study with blinded analysis of the ultrasound data in 28 patients with known coronary artery disease, normal systolic cardiac function and with newly diagnosed type 2 diabetes including impaired glucose tolerance who are treated by ≤1 oral antidiabetic medication. After recruitment and informed consent, patients are randomized to two treatment arms which takes into account age and presence or absence of therapy with statins.

In one treatment arm, therapy is based on insulin glargine sc o.d., while in the other treatment arm, therapy is based on oral metformin, up to 2000 mg daily. Both treatment arms will be titrated to the target of fasting glucose ≤110 mg/dl during the first 12 weeks. The patients in the insulin treatment arm will be instructed in the skills of self-medication by the departmental diabetic teaching programme prior to starting study medication and are encouraged to keep records of any episode of hypoglycemia throughout the study.Outpatients visits for metabolic control and ultrasound assessment are at weeks 4, 12 and 24 after baseline and are associated with life style instructions for all patients.

Inclusion Criteria:

• coronary artery disease
• type 2 diabetes of short duration including impaired glucose tolerance and impaired fasting glucose
• treatment by ≤1 OAD

Exclusion Criteria:

• contraindications for metformin or insulin glargine
• on insulin therapy
• pregnancy and breastfeeding