Is there a cardiomyopathy of obesity?

Obesity is associated with structural and functional changes in the heart. These changes may be precursors to more overt forms of cardiac dysfunction and heart failure. However, it is not known 1) whether cardiac hypertrophy in obese individuals results directly from increased adioposity or from the effects of comorbid conditions such as hypertension, diabetes, and sleep-disordered breathing and 2) whether functional changes (eg, mild reductions in systolic and diastolic function) in obese patients progress over time to the point where they cause heart failure, unless ischemic heart disease develops. Establishing a clear link between obesity and heart failure is complicated by the fact that obesity must be present for many decades before the risk of heart failure increases substantially. At present, there are no longitudinal studies of changes in cardiac size and function in humans with obesity. This article reviews data showing structural and functional changes in the heart in obesity and the evidence that these are or are not progressive over time. At present, we believe it is uncertain whether there is a true "cardiomyopathy of obesity."