Screening for undiagnosed diabetes in patients with acute myocardial infarction

Screening for undiagnosed diabetes in patients with acute myocardial infarction is recommended (ESC and EASD Task Force 2007). Glucose tolerance testing in the peri-infarct period may not be valid because of confounding, e.g. by the acute stress reaction. The aim was to evaluate undiagnosed diabetes (DM) and impaired glucose regulation (IGR) in AMI during hospital stay and 3 months after discharge.

In 96 consecutively admitted AMI patients (Heart Center Wuppertal, Germany) OGTT were performed, of whom in 62 OGTT were also carried out 3 months later.

Before discharge 32% of the patients had newly diagnosed diabetes and 47% patients had prediabetes (IGR). Glucose tolerance was normal in 20 (21%) patients only. After 3 months, 74% with newly diagnosed DM at baseline still had disturbed glucose metabolism (58% DM, 16% IGT). No patient with normal OGTT became diabetic after 3 months. In multivariate regression, the odds of having diabetes (3 months) was about sixfold higher when having diabetes before discharge (OGTT). Admission glucose, infarction size CK(MAX), and inflammation (CRP) were not significantly related to OGTT results.

This prospective study confirms a high prevalence of undiagnosed DM in patients with AMI. In about 60% of AMI patients, newly diagnosed DM persisted after 3 months. For the first time we could show that there is no correlation between infarction size and undiagnosed diabetes. Thus, an OGTT performed before discharge may provide a reliable measure of disturbed glucose regulation but needs to be repeated.