Lower epicardial adipose tissue adiponectin in patients with metabolic syndrome

Adiponectin is an anti-atherogenic insulin-sensitizer hormone whose plasma concentration is lower in patients with metabolic syndrome (MS). Visceral adiposity, including epicardial adipose tissue (EAT), is closely related to the development of MS and coronary artery disease (CAD). We sought to study whether EAT and subcutaneous adipose tissue (SAT) adiponectin mRNA levels are similar in patients with and without MS.

EAT, SAT and blood samples were collected from patients undergoing elective cardiac surgery, for revascularization (n=19) or other procedures (n=27). Plasma adiponectin was measured using ELISA. mRNA was purified and adiponectin mRNA quantified by real time RT-PCR.

Mean (SD) age was 71.6 (9.6) years. Patients who met Adult Treatment Panel III MS criteria (n=29) presented lower plasma adiponectin concentrations (11.2 (7.4) vs. 19.6 (8.4) mg/l, P=0.004), lower EAT adiponectin mRNA (12.7 (3.0) vs. 15.1 (3.7) a.u., P=0.029) and similar SAT adiponectin mRNA levels (13.7 (4.2) vs. 15.6 (5.7) a.u., P=0.25) than those without MS. After adjusting for age, sex, CAD and heart failure, the association with MS remained statistically significant for plasma adiponectin (OR 0.862 (0.762-0.974)), was of borderline significance for EAT adiponectin mRNA (OR 0.796 (0.630-1.005)) and not significant for SAT adiponectin mRNA (OR 0.958 (0.818-1.122)). Patients in the lower quartiles of EAT adiponectin mRNA and plasma adiponectin presented a higher mean of components of the MS.

Subjects with MS present lower EAT adiponectin mRNA levels than those without MS, whereas SAT adiponectin mRNA levels do not seem to differ between both groups. EAT might be the link between MS and its atherothrombotic cardiac complications.