High levels of serum β2-microglobulin predict severity of coronary artery disease

Background: The identification of new risk factors for coronary artery disease (CAD) is increasingly sought in an effort to tackle this threatening disease. beta 2-microglobulin (B2M) is reported to associate with peripheral arterial disease and adverse cardiovascular outcomes. However, the association between B2M and cardiovascular disease remains under-researched. This study evaluated the effects of B2M on CAD without renal dysfunction. Methods: One thousand seven hundred sixty-two subjects (403 non-CAD subjects and 1,359 CAD subjects) were investigated. Fasting samples were collected to determine B2M level. The Gensini and SYNTAX scores were used to assess the severity of CAD. Results: CAD subjects were significantly higher in serum B2M level comparing with non-CAD subjects (1.25 +/- 0.46 vs 1.14 +/- 0.28 mg/L, p < 0.001). Serum B2M level was a risk factor of CAD after adjusting potential confounders (Odds Ratio (OR) = 2.363, 95% confidence interval (CI): 1.467-3.906, p = 0.001). Receiver operating characteristics (ROC) showed B2M level moderately predicted diagnosis of CAD (the area under the ROC curve (AUC) = 0.608, 95% CI: 0.577-0.639, p < 0.001). Furthermore, serum B2M level was positively associated with Gensini score system, SYNTAX score system and the number of disease vessels (NDV >= 2). Conclusions: The significant association between serum B2M and CAD suggests that B2M could be a biomarker for CAD.