Background: Inflammation in epicardial adipose tissue (EAT) contributes to cardiovascular disease through the local production of pro-inflammatory cytokines affecting the adjacent myocardium. Selenium (Se) is essential for selenoprotein-mediated antioxidant and anti-inflammatory functions. We investigated associations between Se status and inflammatory markers in EAT and in the circulation in patients with coronary artery disease (CAD).
Methods: Patients with CAD undergoing coronary artery bypass grafting (n = 52) and valve disease patients receiving valve replacement serving as controls (n = 22) were included from the ATICH study. EAT biopsies were obtained during open-chest chest surgery. Serum Se was measured by inductively coupled plasma mass spectrometry. Associations between Se and EAT mRNA expression of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome components and cytokines, as well as circulating inflammatory markers, were assessed using Spearman's rho and group comparisons based on median Se levels.
Results: Se concentrations were lower in CAD patients than controls (0.9 vs. 1.1 µmol/L, p = 0.025). In CAD patients, Se levels correlated with EAT expression of CASP1 and IL18, and with circulating IL-6. Se levels above the median were associated with lower EAT expression of CASP1 and NLRP3 and reduced IL-6 levels (p < 0.05, all). Our analysis of publicly available RNA seq data demonstrated selenoprotein's presence in EAT.
Conclusion: Lower Se status in CAD was associated with increased systemic and EAT inflammation, suggesting a role for selenoprotein-dependent antioxidant mechanisms in regulating cardiac adipose tissue inflammation.
Keywords: antioxidant defense; coronary artery disease; epicardial adipose tissue; inflammation; selenium status; selenoproteins.