Abstract 11465: Serum Immunoglobulin G4 Levels are Associated with Epicardial Fat Volume but Not with Coronary Artery Calcium Score

Abstract

Objective: Epicardial fat may contribute to the coronary atherosclerosis through the production of inflammatory cytokines. Although immunoglobulin G4 (IgG4)-related disease has been suggested to play a role in cardiovascular remodeling, the relationship between immuno-inflammatory biomarkers and epicardial fat volume (EFV) remains unclear. We analyzed the association between serum levels of IgG4 and soluble interleukin-2 receptor (sIL-2R), another marker for lymphocytic activation, and various parameters obtained by cardiac computed tomography (CT), including EFV, coronary artery calcium (CAC) score, and coronary artery disease (CAD).

Methods: We enrolled 283 patients (164 males; mean age, 68.4 ± 10.0 years) who underwent 320-slice cardiac CT. A total of 155 patients (54.8%) were judged to have CAD. EFV was calculated with semiautomated method.

Results: In patients with CAD, the medians of EFV (109 mL, interquartile range [IR] 83-145), CAC score (322, IR 73-655), and serum levels of IgG4 (29.5 mg/dL, IR 16.1-60.9) and sIL-2R (416 U/mL, IR 339-558) were all significantly higher than in those without (EFV, 90 mL, IR 68-121, P=0.001; CAC score, 12, IR 0-65, P<0.001; IgG4, 21.1 mg/dL, IR 11.0-51.5, P<0.05; sIL-2R, 367 U/mL, IR 229-471, P<0.01). Serum IgG4 levels were significantly associated with EFV (r=0.127, P<0.05), but not with CAC score (r=0.068, P=NS). On the other hand, serum sIL-2R levels were significantly correlated with CAC score (r=0.144, P<0.05), but not with EFV (r=0.095, P=NS). Age and gender-adjusted logistic regression analysis showed that the fourth quartile of IgG4 (≥ 55.4 mg/dL) was significantly associated with the second to fourth quartiles of EFV (≥ 75.4 mL) with an odds ratio of 2.22 (P<0.05).

Conclusions: Serum IgG4 levels were significantly associated with EFV, and serum sIL-2R levels had a close association with CAC. These biomarkers may reflect different mechanism underlying the development of cardiovascular remodeling.