Myocardial steatosis and its association with obesity and regional ventricular dysfunction: Evaluated by magnetic resonance tagging and ¹H spectroscopy in healthy African Americans

Background Cardiac steatosis is common in patients with diabetes or obesity, and cardiac steatosis may result in cardiomyopathy. However, factors associated with cardiac steatosis have not been reported in healthy individuals without diabetes and hypertension. The objectives of this study were to explore factors associated with myocardial triglyceride levels, and to examine the association between myocardial triglyceride and regional left ventricular (LV) function in healthy African Americans (AAs). Methods Between November 2010 and June 2012, 92 healthy AAs aged 21 years or older, without clinical evidence of cardiac dysfunction, coronary artery disease, diabetes, or hypertension from Baltimore, Maryland, were enrolled in an observational proton magnetic resonance spectroscopy and imaging study investigating factors associated with cardiac steatosis, and the relationships between cardiac steatosis and LV volumes and LV function. Results Among the participants, all had a low Framingham risk; 31 had a normal BMI, 23 were overweight and 38 were obese. The median myocardial triglyceride content was 0.5% (IQR: 0.3-1.0%). Among the factors investigated, BMI (R² = 0.43, p = < 0.0001) was independently associated with myocardial triglyceride. Overall, myocardial triglyceride was not associated with LV EF/structure, but may be associated with regional LV function. Conclusions In healthy AA adults, obesity is associated with cardiac steatosis. In contrast to studies in patients with diabetes suggesting a link between cardiac steatosis and LV dysfunction, this study found no relationship between cardiac steatosis and left ventricular volumes or EF, though there is some evidence suggesting that cardiac steatosis may be associated with LV regional function in healthy AA women.