Age-related difference in the impact of diabetes mellitus on all-cause mortality after acute myocardial infarction

Aim: To test the hypothesis that the impact of diabetes mellitus on clinical outcomes after acute myocardial infarction (AMI) can vary by age. Methods: A total of 12,600 AMI patients from the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) between November 2011 and December 2015 was classified into young (n = 3,590 [29%]) and old (n = 9,010 [72%]). Those less than 55 years of age were considered young. We performed comparisons of baseline characteristics, in-hospital treatments, and 3-year clinical outcomes between patients with and without diabetes after stratification according to age group. Results:The prevalence of diabetes mellitus was 27% in the young AMI group. In the multivariable adjusted model of the entire cohort, diabetes mellitus was associated strongly with 3-year all-cause mortality (13% vs. 6.8%; adjusted hazard ratio [HR], 1.318; 95% confidence interval [CI], 1.138-1.526; P<0.001). When the entire cohort was subdivided into two age groups, young diabetic patients showed a 107% higher mortality rate than those without diabetes (adjusted HR, 2.07 [1.15-3.72]; P = 0.015). Meanwhile, old diabetic patients had a 25% higher risk of mortality than non-diabetic patients (adjusted HR, 1.25 [1.08-1.46]; P = 0.004). The interaction of diabetes with age was significant (adjusted P for interaction = 0.008). Conclusions: Diabetes mellitus is not uncommon in younger AMI patients, and the relative risk of 3-year mortality is significantly higher in young patients than in older counterparts. More aggressive treatments are needed to prevent future cardiovascular events in younger patients after AMI. (C) 2022 Elsevier Masson SAS. All rights reserved.