Body Mass Index Enhances the Associations Between Plasma Glucose and Mortality in Patients with Acute Coronary Syndrome

BACKGROUND: It is uncertain whether the effect of hyperglycemia on mortality among patients with acute coronary syndrome (ACS) could be adjusted by other modifiable risk factors. Greater body mass index (BMI) might enhance the effect of fasting blood glucose (FPG) on cardiovascular mortality in patients with ACS. METHODS: We retrospectively enrolled patients admitted for ACS from 2008 to 2017 in Beijing and divided them into three BMI groups (normal weight ≤ 25 kg/m(2), overweight 25–29.9 kg/m(2), obese ≥ 30 kg/m(2)). The relationships between the blood glucose levels and all-cause or cardiovascular mortalities and their heterogeneities across the groups were analyzed using Cox regression models. RESULTS: A total of 8,086 patients were enrolled, with 746 all-cause and 496 cardiovascular mortalities recorded during the follow-up period. Each 1 mmol/L increase in FPG was associated with an increased risk of all-cause mortality across all groups (adjusted hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.02–1.09 for normal weight patients; adjusted HR: 1.09, 95% CI: 1.05–1.13 for overweight patients; adjusted HR: 1.12, 95% CI: 1.03–1.22 for obese patients), and was associated with an increased risk of cardiovascular mortality among overweight (adjusted HR: 1.10, 95% CI: 1.05–1.14) and obese patients (adjusted HR: 1.15, 95% CI: 1.04–1.26), which was greater (p for heterogeneity = 0.006) than the association in the normal weight group (adjusted HR: 1.03, 95% CI: 0.99–1.08). Similar results were found among 2,537 patients with ACS diagnosed with diabetes. CONCLUSION: Greater BMI enhances the effect of FPG on cardiovascular mortality among patients with ACS.