Body mass index and cardiovascular outcomes in patients with acute coronary syndrome by diabetes status: the obesity paradox in a Korean national cohort study

Abstract

BACKGROUND: The "obesity paradox" has not been elucidated in the long-term outcomes of acute coronary syndrome (ACS). We investigated the association between obesity and cardiovascular (CV) outcomes in ACS patients with and without diabetes. <br>METHODS: We identified 6978 patients with ACS aged 40-79 years from the Korean National Health Insurance Service-Health Screening Cohort between 2002 and 2015. Baseline body mass index (BMI) was categorized as underweight (&lt; 18.5 kg/m(2)), normal weight (18.5-22.9 kg/m(2)), overweight (23.0-24.9 kg/m(2)), obese class I (25.0-29.9 kg/m(2)), and obese class II (&gt;/= 30.0 kg/m(2)). The primary outcome was major adverse CV events (MACE)-CV death, myocardial infarction (MI), and stroke. The secondary outcomes were the individual components of MACE, hospitalization for heart failure (HHF), and all-cause death. <br>RESULTS: After adjustment for confounding variables, compared to normal-weight patients without diabetes (reference group), obese class I patients with and without diabetes had a lower risk of MACE, but only significant in patients without diabetes (with diabetes: hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.78-1.14; without diabetes: HR 0.78, 95% CI 0.62-0.97). Obese class II patient with diabetes had a higher risk of MACE with no statistical significance (HR 1.14, 95% CI 0.82-1.59). Underweight patients with and without diabetes had a higher risk of MACE, but only significant in patients with diabetes (with diabetes: HR 1.79, 95% CI 1.24-2.58; without diabetes: HR 1.23, 95% CI 0.77-1.97). <br>CONCLUSION: In ACS patients, obesity had a protective effect on CV outcomes, especially in patients without diabetes.