Associations between the IL-6-neutralizing sIL-6R-sgp130 buffer system and coronary artery disease in postmenopausal women

As a major inflammatory pathway in coronary artery disease (CAD), IL-6 trans-signaling is activated by the IL-6: sIL-6Rα binary complex (B) and inhibited by sgp130 through forming the IL-6: sIL-6Rα: sgp130 ternary complex (T). The

Based on this small case-control study, sgp130 and B/T ratio in the IL-6-neutralizing sIL-6R-sgp130 buffer system may be promising biomarkers for CAD diagnosis and assessments of coronary stenosis severity in postmenopausal women.

Our study recruited 155 CAD patients and 181 controls among postmenopausal women. Circulating levels of IL-6, sIL-6Rα and sgp130 were detected using an enzyme-linked immunosorbent assay, and the B/T ratio was calculated by the specific formulas.

CAD patients showed significantly higher circulating levels of IL-6 and sIL-6Rα, significantly higher B/T ratio, and significantly lower sgp130 levels than controls (all P<0.05). Spearman's correlation analysis indicated that IL-6 levels (r=0.185, P<0.01) and B/T ratio (r=0.319, P<0.01) were positively related to Gensini scores, while elevated sgp130 levels were significantly associated with decreased Gensini scores (r=-0.565, P<0.001). In addition, multiple regression analysis showed that Gensini scores were negatively associated with serum sgp130 levels (β-coefficient =-0.318, P<0.001) and had a positive association with IL-6 levels (β-coefficient =0.138, P<0.05). Multivariate logistic regression analysis identified that after adjusting for confounding factors, higher sgp130 remained an independent predictor of lower incidence of CAD in women after menopause (OR =0.904; 95% CI: 0.837-0.976, P=0.010). Moreover, sgp130 levels at 136.01 ng/mL (AUC =0.957, 95% CI: 0.928-0.986, P<0.001) and B/T ratio at 1.51 (AUC =0.765; 95% CI: 0.702-0.828, P<0.001) were effective cut-off points to determine the presence of CAD based on receiver operating characteristic curves. Conclusions: Based on this small case-control study, sgp130 and B/T ratio in the IL-6-neutralizing sIL-6R-sgp130 buffer system may be promising biomarkers for CAD diagnosis and assessments of coronary stenosis severity in postmenopausal women.