Temporal change in glucose tolerance in non-ST-elevation myocardial infarction

We assessed the prevalence and 3-month change in glucose tolerance status in consecutive non-ST-elevation myocardial infarction (NSTEMI; European Society of Cardiology 2007 definition) patients (N = 49; mean (S.D.) age 65 (11) years) admitted to a coronary care unit, without known diabetes. These patients underwent an oral glucose tolerance test (OGTT) 36-hour (median, IQR: 18-72) after admission and at 3 months. Undiagnosed abnormal glucose tolerance (AGT: impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or new diabetes) was common (61% at admission and 41% at 3 months, p < 0.05) and the majority (∼3/4) had IGT. Glucose tolerance status improved in a higher proportion of patients than it worsened (31% vs. 8%, p = 0.04). At 3 months, fasting glucose was unchanged but 2-hour OGTT glucose was lower (mean (S.D.): 8.5 (2.7) mmol/L vs. 7.7 (2.7) mmol/L, p = 0.004). 'Stress hyperglycaemia' could explain higher admission glucose levels and this raises the question about the optimal timing of OGTT in relation to myocardial infarction. Newly diagnosed diabetes was present in ∼10% of patients and this was not reliably detected by fasting plasma glucose. In NSTEMI patients OGTT is the only reliable strategy to identify subjects with IGT and diabetes.