Obesity is associated with premature occurrence of acute myocardial infarction

Background: The American Heart Association has classified obesity as a major modifiable risk factor for coronary artery disease, but its relationship with age at presentation with acute myocardial infarction (AMI) is poorly documented. Hypothesis: The study was undertaken to evaluate the impact of obesity on age at presentation, and on in-hospital morbidity and mortality in patients with AMI. Methods: Our analysis includes a consecutive series of 906 Olmsted County patients (mean age 67.7 years, 51% male) admitted with AMI to the Mayo Clinic Coronary Care Unit (CCU). The patients were entered into the Mayo CCU Database, a prospective registry of data pertaining to patients admitted to the Mayo Clinic CCU with AMI. Age at AMI occurrence and in-hospital morbidity and mortality were noted. Results: Obese patients (body mass index [BMI] > 30) with AMI were significantly younger than patients with AMI in the overweight (BMI 25-30) and normal-weight (BMI <30) groups (62.3±13.1 vs. 66.9±13.2 and 72.9± 13.4, respectively, p < 0.001). Obesity and overweight status were associated with male gender, diabetes mellitus, hypercholesterolemia, and smoking history; however, after multivariate adjustment for these risk factors, excess weight and premature AMI remained significantly associated. Compared with normal-weight patients, overweight patients presenting with AMI were 3.6 years younger (p<0.001, confidence interval [CI] 1.9-5.4) and obese patients 8.2 years younger (p<0.001, CI 6.2-10.1). No significant increase in in-hospital morbidity and mortality was seen. Conclusion: In this population-based study, overweight and obese status are independently associated with the premature occurrence of AMI, but not with an increased incidence of in-hospital complications.