Circulatory soluble LOX-1 is a novel predictor for coronary artery disease patients

Objective: This study investigated the biomarker effect of soluble lectin-like oxidised low-density lipoprotein (sLOX-1) levels for the evaluation of stable and unstable coronary heart disease, correlating it with aging. Methods: This case-control study was conducted at the Cardiology Department of Xiangya Hospital between June 2015 and September 2018. Stable coronary artery disease (CAD) patients were confirmed by an invasive coronary angiogram, and American College of Cardiology as well as European Cardiology Society clinical protocols were used for the diagnosis of unstable CAD subjects. Plasma sLOX-1 levels were determined from 226 stable CAD patients, 138 unstable CAD subjects and 75 healthy participants by enzyme-linked immunosorbent assay. Results: Plasma sLOX-1 expressions were significantly elevated in stable CAD patients (4.5-fold) and unstable CAD patients (5.8-fold) above that of volunteer healthy participants. Moreover, between the stable and unstable patient groups, sLOX-1 concentrations were also statistically significantly different (p < 0.001). Levels of plasma sLOX-1 in the healthy female (30-60 years), and stable and unstable CAD female subjects (61-84 years) were markedly elevated compared with healthy male (30-60 years), as well as stable and unstable CAD male patients (61-84 years) (p < 0.001). Besides, in the female unstable CAD (61-84 years) subjects, circulatory sLOX-1 expressions were much higher than in the younger female unstable CAD (30-60 years) patients (p < 0.001). The stable CAD patients were clearly differentiated from healthy subjects with a high sensitivity of the area under the curve (AUC = 0.895). Unstable CAD patients and healthy subjects were also markedly different with a high sensitivity, as shown by AUC (0.902). Stable and unstable CAD subjects were differentiated with an AUC of 0.867. Conclusion: Elevated plasma sLOX-1 levels could be regarded as a novel biomarker for detecting CAD patients and there was a significant association with gender and aging.