Relationship between interleukin-1β gene expression in epicardial adipose tissue and coronary atherosclerosis based on computed tomographic analysis.

Background: Anti-inflammatory therapy targeting interleukin (IL)-1β reduced cardiovascular events in a randomized trial. We evaluated the relationship between IL-1β mRNA expression in epicardial adipose tissue (EAT) and clinically-assessed coronary atherosclerosis on computed tomography (CT).

Methods: We studied 45 patients before cardiac surgery (coronary artery bypass grafting [CABG], n ​= ​18; non-CABG, n ​= ​27). EAT volume, the coronary calcium score (CCS), and the presence of non- and/or partially-calcified coronary plaques (NCPs) and high-risk coronary plaques (HRPs; minimum CT density <30 Hounsfield units and vascular remodeling index >1.1) on CT angiography were assessed. EAT samples were obtained during cardiac surgery. IL-1β mRNA expression in EAT was measured using quantitative real-time PCR and normalized to that of β-actin in each patient.

Results: There was no difference in IL-1β mRNA levels between patients who were scheduled for CABG and non-CABG surgery or among subgroups based on the CCS. However, patients with NCPs (median [interquartile range], 4.1[2.0-11.6]E-4 versus 1.8[0.6-4.5]E-4, p ​= ​0.024) and HRP (7.6[3.0-20.4]E-4 versus 1.9[0.7-4.3]E-4, p ​= ​0.0023) had higher IL-1β mRNA levels than those without these plaques. On multivariate analysis adjusted for age, sex, coronary risk factors, statin therapy, CCS, and EAT volume, the presence of HRPs was significantly correlated with elevated IL-1β mRNA levels in EAT (β ​= ​0.39, p ​= ​0.047).

Conclusion: Our data suggest a contribution of EAT to coronary atherosclerosis through molecular behavior, such as IL-1β gene expression, which may be a new therapeutic target.