Weight status constitutes a significant role in the progression of atherosclerotic disease
[39]. Obesity is characterized by excessive expansion of visceral white adipose tissue mass, also known as adiposopathy. Adiposopathy is comprised of adipocyte hypertrophy, decreased adipose tissue blood flow, altered oxygen levels within the tissue, a state of chronic low-grade inflammation and blunted lipid metabolism
[40][41][42]. The latter includes impaired capacity for storing the surplus of dietary lipids, resulting in deposition of ectopic fat accumulating in body locations where it is not physiologically stored, such as the liver and muscle, and a shift to visceral adipose tissue (fat storage in the intraperitoneal and retroperitoneal spaces), contributing to increased circulating free fatty acids, oxidative stress, systemic inflammation, adipokine dysregulation and insulin resistance
[40][41][42][43][44][45]. However, epicardial adipose tissue has several unique properties that distinguish it from other depots of visceral fat due to the common microcirculation of epicardial tissue and the underlying myocardium
[46]. The accumulation of epicardial fat is closely associated with an impaired myocardial microcirculation, cardiac diastolic filling abnormalities, increased vascular stiffness, and left atrial dilatation in obese people
[47][48]. More specifically, high levels of TNF-α induce the secretion of adhesion and chemoattractant molecules such as vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and monocyte chemoattractant protein-1 while reducing nitric oxide availability. Resistin hormone stimulates the proliferation of smooth muscle cells and the over-secretion of endotelin-1, leading to endothelial dysfunction
[49]. Obesity-related reductions in myocardial blood flow due to CMVD, combined with increased cardiac metabolic demand due to increases in ventricular mass, volume expansion, higher filling pressures, and greater cardiac output, may create a perfect background for the occurrence of myocardial oxygen supply–demand mismatch
[36]. Finally, an unfavorable correlation was observed between CFR and increased LDL cholesterol where treatment with pioglitazone and lipid-lowering therapy seemed to improve CFR
[50].