Background: Diabetes and impaired glucose tolerance are associated with increased mortality in patients with acute myocardial infarction. We have used standardised oral glucose tolerance tests shortly after a myocardial infarction.
Methods: 109 patients admitted with acute myocardial infarction were prospectively enrolled in the study. An oral glucose tolerance test was performed the first morning the patients were stable, without pain, nausea or hyperglycaemia. The patients were classified into normal glucose tolerance, impaired glucose tolerance or diabetes, according to the results of the oral glucose tolerance test and fasting plasma glucose levels.
Results: 109 patients (25 women) were included. Eight patients were previously diagnosed with diabetes type 2. Oral glucose tolerance was tested for 90 patients, usually the day after admission. The test was positive in 47 patients; 32 of them had 2-h plasma glucose levels between 7.8 and 11.0 mmol/L and were classified as having impaired glucose tolerance, and 15 had 2-h plasma glucose > or = 11.1 mmol/L and were classified as newly diagnosed diabetes patients. Similar body mass indexes and lipid values were found in patients with different glycometabolic states. Smoking was associated with a positive oral glucose tolerance test.
Interpretation: More than half of the patients with acute myocardial infarction had undiagnosed impaired glucose tolerance or diabetes type 2, as determined by an oral glucose tolerance test. The test could easily be performed shortly after a myocardial infarction in most of the patients. Oral glucose tolerance testing should be considered in all patients with coronary heart disease without a history of diagnosed diabetes.