Trends in Endocrinology & Metabolism
ReviewEpicardial adipose tissue: emerging physiological, pathophysiological and clinical features
Section snippets
Anatomy of epicardial adipose tissue
The adipose tissue of the heart consists of epicardial fat (Table 1), located between the myocardium and visceral pericardium, and the pericardial fat, situated outside the visceral pericardium and on the external surface of the parietal pericardium 1, 2, 3, 4, 5, 6, 7, 8. Epicardial and pericardial fat are embryologically different. The epicardium comprises a population of mesothelial cells that migrate onto the surface of the heart from the area of the septum transversum 1, 2, 3, 4.
Epicardial adipose tissue and myocardial metabolism
Epicardial fat is not merely a passive lipid-storage unit, but is actively involved in lipid and energy homeostasis (Table 2) 1, 2, 3, 4. The principal difference between epicardial adipose tissue and other visceral fat depots is its greater capacity for release and uptake free fatty acids (FFAs) and a lower rate of glucose utilization. Indeed, FFA synthesis and rates of incorporation and breakdown are significantly higher in epicardial fat than other fat depots [17]. Higher rates of lipolysis
Epicardial adipose tissue as brown fat
Brown adipose tissue generates heat in response to cold temperatures and activation of the autonomic nervous system [20]. However, the presence and role of brown fat in humans is unclear. Very recently, expression of uncoupling protein-1 (UCP-1), a marker of brown fat, has been reported in human epicardial fat [21]. UCP-1 expression was significantly higher in human epicardial fat than in other fat depots, therefore suggesting that epicardial fat might function in the same way as brown fat to
Epicardial adipose tissue as an endocrine and paracrine organ
Human epicardial fat is a metabolically active organ and a source of several bioactive molecules (Table 3) that might substantially influence the myocardium and coronary arteries 1, 10, 23, 24, 25, 26, 27, 28. Two major mechanisms of interaction between the myocardium and the epicardial fat (i.e. paracrine and vasocrine) (Figure 2), have been suggested [3]. Paracrine release of cytokines from periadventitial epicardial fat could traverse the coronary wall by outside-to-inside diffusion. Given
Imaging of epicardial adipose tissue
Epicardial fat can be easily detected and measured by imaging. Ultrasound provides a simple and readily available assessment, whereas multi-detector computed tomography (MDCT) or cardiac magnetic-resonance imaging (MRI) allow an accurate but more expensive and cumbersome measurement. Overall, objective and reproducible measurement of epicardial fat is certainly a promising tool in both the clinical and research setting. Epicardial fat thickness was first visualized and measured with
Concluding remarks
Epicardial fat is a heart fat depot with unique anatomical and functional characteristics. Epicardial adipocytes are smaller in size than those of other fat depots, and with different fatty acid composition, higher rates of FFA synthesis, uptake and release, and lower rates of glucose utilization. Epicardial fat is also a source of several bioactive molecules and, given its anatomical proximity to the heart, it is thought to interact locally with the coronary arteries and the myocardium through
References (88)
- et al.
Human epicardial adipose tissue: a review
Am. Heart J.
(2007) The ventricular epicardial fat is related to the myocardial mass in normal, ischemic and hypertrophic hearts
Cardiovasc. Pathol.
(2004)Quantification of epicardial and peri-coronary fat using cardiac computed tomography: reproducibility and relation with obesity and metabolic syndrome in patients suspected of CAD
Atherosclerosis
(2008)Relationship between epicardial adipose tissue adipocyte size and MCP-1 expression
Cytokine
(2010)Age and sex mediated changes in epicardial fat adipokines
Atherosclerosis
(2010)- et al.
Echocardiographic epicardial fat: a review of research and clinical applications
J. Am. Soc. Echocardiogr.
(2009) Adipose tissue in the mammalian heart and pericardium; structure, foetal development and biochemical properties
Comp. Biochem. Physiol.
(1989)Presence of fatty-acid-binding protein 4 expression in human epicardial adipose tissue in metabolic syndrome
Cardiovasc. Pathol.
(2008)Neurotrophin presence in human coronary atherosclerosis and metabolic syndrome: a role for NGF and BDNF in cardiovascular disease?
Prog. Brain Res.
(2004)Human epicardial adipokine messenger RNAs: comparisons of their expression in substernal, subcutaneous, and omental fat
Metabolism
(2010)
Epicardial fat thickness and CAD correlate independently of obesity
Int. J. Cardiol.
Relationship of subepicardial adipose tissue with carotid intima media thickness in HIV-infected patients
Am. J. Cardiol.
Ectopic fat and cardiovascular disease: what is the link
Nutr. Metab. Cardiovasc. Dis.
Relation of echocardiographic epicardial fat thickness and myocardial fat
Am. J. Cardiol.
Adiponectin expression in human epicardial adipose tissue in vivo is lower in patients with CAD
Cytokine
Validation of cardiovascular magnetic resonance assessment of pericardial adipose tissue volume
J. Cardiovasc. Magn. Reson.
Clinical significance of epicardial fat measured using cardiac multislice computed tomography
Am. J. Cardiol.
Relationship of epicardial fat thickness and fasting glucose
Int. J. Cardiol.
Epicardial fat thickness: Relationship with plasma visfatin and plasminogen activator inhibitor-1 levels in visceral obesity
Nutr. Metab. Cardiovasc. Dis.
Relation between epicardial fat thickness and coronary flow reserve in women with chest pain and angiographically normal coronary arteries
Atherosclerosis
Epicardial adipose tissue thickness by echocardiography is a marker for the presence and severity of CAD
Nutr. Metab. Cardiovasc. Dis.
Relation of epicardial and pericoronary fat to coronary atherosclerosis and coronary artery calcium in patients undergoing coronary angiography
Am. J. Cardiol.
Increased epicardial, pericardial, and subcutaneous adipose tissue is associated with the presence and severity of coronary artery calcium
Acad. radiol.
Epicardial adipose tissue and coronary artery plaque characteristics
Atherosclerosis
Relation of epicardial adipose tissue to coronary atherosclerosis
Am. J. Cardiol.
Relation between epicardial adipose tissue and left ventricular mass
Am. J. Cardiol.
Relation of epicardial fat thickness to right ventricular cavity size in obese subjects
Am. J. Cardiol.
Relationship of epicardial adipose tissue with atrial dimensions and diastolic function in morbidly obese subjects
Int. J. Cardiol.
Pericardial fat is independently associated with human atrial fibrillation
J. Am. Coll. Cardiol.
Effects of weight loss after bariatric surgery on epicardial fat measured using echocardiography
Am. J. Cardiol.
Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart
Nat. Clin. Pract. Cardiovasc. Med.
Epicardial and pericardial fat: close, but very different
Obesity
Epicardial fat: properties, function and relationship to obesity
Obes. Rev.
Do cardiac and perivascular adipose tissue play a role in atherosclerosis?
Curr. Diab. Rep.
Pericardial adipose tissue determined by dual score CT is a risk factor for coronary atherosclerosis
Arterioscler. Thromb. Vasc. Biol.
Epicardial fat gene expression after aerobic exercise training in pigs with coronary atherosclerosis: relationship to visceral and subcutaneous fat
J. Appl. Physiol.
Human epicardial adipose tissue is a source of inflammatory mediators
Circulation
Adiponectin gene expression and adipocyte diameter: a comparison between epicardial and subcutaneous adipose tissue in men
Cardiovasc. Pathol.
Antiadipogenic effects of the mineralocorticoid receptor antagonist drospirenone: potential implications for the treatment of metabolic syndrome
Endocrinology
Fat in the right ventricle of the normal heart
Histopathology
Fatty acid composition of epicardial and subcutaneous human adipose tissue
Metab. Syndr. Relat. Disord.
Brown fat biology and thermogenesis
Front. Biosci.
Uncoupling Protein-1 and related mRNAs in human epicardial and other adipose tissues: epicardial fat functioning as brown fat
J. Clin. Endocrinol. Metab.
Cold-activated brown adipose tissue in healthy men
N. Engl. J. Med.
Cited by (404)
Epicardial fat in patients with metabolic syndrome: A systematic review and meta-analysis
2023, European Journal of RadiologyEpicardial adipose tissue and cardiac lipotoxicity: A review
2023, Life SciencesHeart Failure and Obesity: The Latest Pandemic
2023, Progress in Cardiovascular DiseasesEvaluation of subclinical cardiovascular risk in drug-naive pediatric patients with anxiety disorders
2024, International Journal of Psychiatry in MedicineHeart-on-a-chip systems: disease modeling and drug screening applications
2024, Lab on a Chip