Contrasting Associations of Body Mass Index and Hemoglobin A1c on the Excess Risk of Acute Myocardial Infarction and Heart Failure in Type 2 Diabetes Mellitus

Abstract

Background Body mass index (BMI) may be a stronger risk factor for heart failure than for coronary heart disease in type 2 diabetes mellitus, but prior studies have not been powered to investigate the relative and absolute risks for acute myocardial infarction and heart failure in type 2 diabetes mellitus by BMI and glycemic level combined as compared with age‐ and sex‐matched general population comparators. Methods and Results We identified 181 045 patients from The Swedish National Diabetes Registry, registered during 1998 to 2012 and 1538 434 general population comparators without diabetes mellitus, matched for age, sex, and county, all without prior major cardiovascular disease. Cases and comparators were followed with respect to the outcomes through linkage to the Swedish Inpatient Registry. Over a median follow‐up time of 5.7 years, there were 28 855 acute myocardial infarction and 33 060 heart failure cases among patients and comparators. Excess risk (above that of comparators in whom no data on hemoglobin A1c and BMI was available), incidence rates and hazard ratios for heart failure were substantially higher among the obese patients compared with those with low BMI, where very obese patients (BMI ≥40 kg/m2) who also had poor glycemic control, suffered a 7‐fold risk of heart failure versus comparators (reference level). By contrast, for acute myocardial infarction, the highest absolute and relative risks were found among patients with poor glycemic control, with no additional risk conferred by increasing BMI. Conclusions BMI is a strong independent risk factor for heart failure but not for acute myocardial infarction among patients with type 2 diabetes mellitus.

Keywords

• body mass index
• glucose
• heart failure
• myocardial infarction
• type 2 diabetes mellitus