Admission Blood Glucose Level as Risk Indicator of Death After Myocardial Infarction in Patients With and Without Diabetes Mellitus

Abstract

Diabetes mellitus is associated with a high risk of coronary heart disease,^1,2 and subjects with diabetes have a substantially increased risk of death after acute myocardial infarction (AMI), as compared with nondiabetic age-matched controls.^3,4 High blood glucose levels in patients admitted with AMI are common and are associated with an increased risk of death in both diabetic^5-7 and nondiabetic^7-10 subjects. A recent report showed that, of patients who had no known diabetes at the time of AMI and whose admission blood glucose levels were less than 200 mg/dL (11.1 mmol/L), up to 40% were diagnosed as having impaired glucose tolerance and 25% as having diabetes when tested 3 months after discharge.¹¹ The high prevalence of undiscovered abnormal glucose metabolism among patients with AMI, compatible with the prediabetic state as well as frank diabetes, may in part explain the association between admission glucose levels and mortality, especially in subjects who are not diagnosed as having diabetes at the time of the AMI.^9,10 Although the diagnosis of diabetes may not be made on the basis of a single blood glucose value,^12,13 casual blood glucose levels of 200 mg/dL (11.1 mmol/L) or more suggest the existence of diabetes, and as a consequence, the risk of mortality after AMI in this group may be disproportionately high and should be evaluated separately. In the study by Norhammar et al,¹¹ subjects with glucose levels of 200 mg/dL (11.1 mmol/L) or higher were excluded.