Background/AimsThis study compared long-term clinical outcomes between male and female acute myocardial infarction (AMI) patients with and without diabetes mellitus (DM).MethodsFrom November 2011 to December 2015, 13,104 patients with AMI were enrolled in the Korea Acute Myocardial Infarction Registry National Institutes of Health (KAMIR-NIH) (4,458 diabetic patients and 8,646 non-diabetic patients). Propensity score matching (PSM) was used to reduce bias due to confounding variables. Following PSM, 2,046 diabetic patients, 1,023 males (69.8 ± 9.4 years) and 1,023 females (69.9 ± 9.4 years); and 3,412 non-diabetic patients, 1,706 males (70.0 ± 10.4 years) and 1,706 females (70.4 ± 10.8 years) were analyzed. Clinical outcomes were compared between male and female patients with and without diabetes over a 3-year clinical follow-up.ResultsIn diabetic patients, mortality (21.1% vs. 21.5%, p = 0.813) and major adverse cardiac events (MACE) (30.6% vs. 31.4%, p = 0.698) were not significantly different between males and females. However, mortality (15.8% vs. 12.0%, p = 0.002) and MACE (20.8% vs. 15.6%, p < 0.001) were significantly higher in male non-diabetic patients than in female non-diabetic patients. The predictors of mortality for both males and females in the diabetic and non-diabetic groups were old age, heart failure, renal dysfunction, anemia, and no percutaneous coronary intervention.ConclusionsThe long-term clinical outcomes in AMI patients with DM did not significantly differ by sex. However, the mortality and MACE in non-diabetic male patients were higher than those in females.