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 < 0.00 1, confidence interval [CI] 1.9-5.4) and obese patients 8.2 years younger (p < 0.001, CI 62-10.1). 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 inhospital complications.