Body mass index and cardiovascular outcomes in patients with acute coronary syndrome by diabetic status: Korean cohort study

Abstract

Background: The “obesity paradox” has not been elucidated in the long-term outcomes of acute coronary syndrome (ACS). Therefore, we investigated the association between obesity and cardiovascular (CV) outcomes in ACS patients with and without diabetes.Methods: We identified 6,978 patients with ACS aged 40–79 years from the Korean National Health Insurance Service-Health Screening Cohort between 2003 and 2015. Baseline body mass index (BMI) was categorized as underweight (<18.5 kg/m2), normal weight (18.5–22.9 kg/m2), overweight (23.0–24.9 kg/m2), obese class I (25.0–29.9 kg/m2), and obese class II (≥30.0 kg/m2). 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. Results: The study included 3,989 patients with and 2,989 without diabetes. Compared to normal-weight patients without diabetes (reference group), those with diabetes had a higher risk of MACE (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.07–1.56). Obese patients without diabetes had a lower risk of MACE (HR, 0.78; 95% CI, 0.62–0.97) than those with diabetes (HR, 0.95; 95% CI 0.78–1.14). In patients without diabetes, obese BMI decreased the risk of HHF (HR, 0.62; 95% CI, 0.42–0.92) and stroke (HR, 0.61; 95% CI, 0.42–0.88), but not in those with diabetes. Conclusion: Among patients with ACS, obesity had rather protective effect on CV outcomes compared to normal weight, while this was not evident in patients with diabetes.