Stress hyperglycaemia is a predictor of abnormal glucose tolerance in Indian patients with acute myocardial infarction.

66 non-diabetic Indian patients with acute myocardial infarction were assessed prospectively for the presence of hyperglycaemia and the value of this admission hyperglycaemia and glycosylated haemoglobin (HbA1) levels in reflecting the glucose tolerance status of the patients was studied. Hyperglycaemia, defined as admission plasma glucose greater than or equal to 8 mmol/l was detected in 49% of the patients, whilst raised HbA1 values were seen in 11%. The admission plasma glucose (APG) correlated significantly with both the HbA1 levels and with the 2 hour glucose value in the oral glucose tolerance test (p less than 0.001). An oral glucose tolerance test performed 3 months after the acute episode revealed that 35 patients (53%) had abnormal glucose tolerance according to WHO criteria. Of the patients with initial hyperglycaemia, 75% had abnormal glucose tolerance tests, whilst 32% of patients with normal APG had abnormal glucose tolerance. Abnormal glucose tolerance was also detected in all patients with raised HbA1 values (greater than 8.9%) and in 48% of patients with normal levels. The sensitivity and specificity of APG greater than or equal to 8 mmol/l for abnormal glucose tolerance was 68.6% and 74.2% respectively and that of raised HbA1 values were 20% and 100%. Hence an APG greater than or equal to 8 mmol/l in patients with myocardial infarction is more likely to indicate the presence of unrecognized abnormal glucose tolerance rather than stress. HbA1 measurements do not appear to offer any further advantage in the assessment of hyperglycaemia following myocardial infarction.