Hypoglycemia at Admission in Patients With Acute Myocardial Infarction Predicts a Higher 30-Day Mortality in Patients With Poorly Controlled Type 2 Diabetes Than in Well-Controlled Patients

OBJECTIVE We aimed to evaluate the association between hypoglycemia at admission and 30-day mortality in patients with acute myocardial infarction (AMI) and to determine whether these associations differed according to diabetes-control status in AMI patients with diabetes. RESEARCH DESIGN AND METHODS We analyzed the prognostic significance of hypoglycemia and hyperglycemia in 34,943 AMI patients with or without type 2 diabetes from two AMI registries: the Korea Acute Myocardial Infarction Registry (KAMIR) and the Korea Working Group on Myocardial Infarction (KorMI). RESULTS The patients were divided into five groups according to serum-glucose levels at admission: <3.9 mmol/L (<70 mg/dL); 3.9-7.72 mmol/L (70-139 mg/dL); 7.78-11.06 mmol/L (140-199 mg/dL); 11.11-14.39 mmol/L (200-259 mg/dL); and >= 14.44 mmol/L (>= 260 mg/dL). The 30-day mortality rates in the lowest and highest glucose groups were higher than those in other groups; the lowest glucose group had the highest mortality for patients with type 2 diabetes, after adjusting for multiple factors. We also extracted and compared four subgroups from the patients with type 2 diabetes, based on hemoglobin A1c and serum-glucose levels at admission: group A, <6.5% (48mmol/mol) and <3.9mmol/L; group B, <6.5% (48 mmol/mol) and >= 11.11 mmol/L; group C, >= 8% (64 mmol/mol) and <3.9 mmol/L; and group D, >= 8% (64 mmol/mol) and >= 11.11mmol/L. Group C had the highest 30-day mortality rate among the groups. CONCLUSIONS These data suggest that hypoglycemia at admission affects clinical outcomes differently in AMI patients with type 2 diabetes depending on the diabetes-control status.