Impact of abdominal and epicardial fat on the association between plasma adipocytokine levels and coronary atherosclerosis in non-obese patients

•There was no correlation between plasma levels of adipocytokine and epicardial fat volume (EFV).•Subjects with noncalcified plaque had increased EFV but their adipocytokine levels did not increased.•Adiponectin and IL-6 levels were correlated with abdominal visceral fat area in patients with coronary plaque.•Epicardial fat may promote coronary atherosclerosis directly through paracrine effects rather than systemic effects.

Objective: Ectopic fat accumulation is associated with coronary artery disease. Visceral adipose tissue has paracrine and systemic effects and is a source of adipocytokines. It has been implicated in the pathogenesis of coronary atherosclerosis; however, nothing is known about whether increases in epicardial fat have the same effect on coronary atherosclerosis as increases in abdominal visceral fat. Methods: We examined 216 consecutive patients suspected to have coronary artery disease. Individuals with acute coronary syndrome and inadequate computed tomography (CT) imaging were excluded. We enrolled 164 patients (65 ± 10 years old; 70% men; body mass index [BMI], 23.8 ± 3.6 kg/m2). The plasma concentrations of adiponectin, interleukin-6 (IL-6), plasminogen activator inhibitor-1, and vascular endothelial growth factor were measured. The characteristics of coronary plaque, abdominal visceral fat area, and epicardial fat volume (EFV) were determined by 64-slice CT imaging. Results: EFV was greater in subjects with noncalcified plaque than in those with no plaque or with calcified plaque (126 ± 39 mL vs. 98 ± 34 mL and 97 ± 45 mL, respectively; P = 0.010). EFV was significantly correlated with BMI, triglycerides, and the triglyceride/high-density lipoprotein cholesterol ratio (r = 0.51, 0.19, and 0.20, respectively) but not with plasma levels of adipocytokines. The plasma adiponectin and IL-6 concentration was significantly correlated with abdominal visceral fat area in coronary plaque patients (r = −0.49 and 0.20). Conclusions: In non-obese Japanese patients, epicardial fat may have unique mechanisms affecting the development of coronary atherosclerosis, which is different from abdominal visceral fat.