The role of cardiac fat in insulin resistance

Purpose of review To evaluate the relationship between cardiac fat accumulation and insulin resistance. We discuss the current knowledge regarding the different techniques for measuring, in vivo in humans, cardiac fat deposition, the effects of systemic and myocardial insulin resistance and the clinical relevance of the relation between atherosclerosis and cardiac fat in conditions of insulin resistance. Recent findings In humans, fat accumulates mainly around the heart, as epicardial, perivascular and intrathoracic fat, but also inside the cardiomyocytes. All these cardiac fat depots have been shown to be markers of cardiac lipotoxicity, mitochondrial dysfunction, inflammation and local and systemic insulin resistance as well as of atherosclerosis and cardiac dysfunction. Summary Although cardiac fat is associated with impairment in heart metabolism and cardiac dysfunction, the interplay among cardiac fat accumulation, insulin resistance and cardiac dysfunction remains to be fully established.