Plasma neutrophil gelatinase-associated lipocalin levels are associated with the presence and severity of coronary heart disease

Objective This study aimed to compare the levels of plasma neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase (MMP)-9, high-sensitivity C-reactive protein (hs-CRP), and interleukin (IL)-1 beta across different clinical presentations of coronary artery disease and to evaluate the relationship between those biomarkers and the severity of coronary artery lesions in patients without kidney disease. Methods We examined 365 eligible patients who underwent coronary angiography. A total of 124 ST-segment elevation myocardial infarction (STEMI) patients, 117 stable angina pectoris (SAP) patients and 124 patients without atherosclerotic plaques were enrolled in the study. Plasma NGAL, MMP-9, hs-CRP, and IL-1 beta were measured in all patients using the enzyme-linked immunosorbent assay (ELISA) method. According to the SYNTAX score, the STEMI patients and SAP patients were divided into another set of 2 groups: a high score group (>= 33, n = 29) and a low score group (< 33, n = 212). The relationship between those biomarkers and the severity of coronary stenosis was examined by Spearman correlation analysis; the ability for NGAL to discriminate severe coronary stenosis was examined by receiver operating characteristic (ROC) curve; the influencing factors for the SYNTAX score were determined by logistic regression analysis. Results Plasma NGAL, MMP-9, and hs-CRP levels in STEMI patients were higher than in the SAP patients and control subjects (P< 0.05, respectively), and plasma NGAL and hs-CRP levels were significantly higher in the SAP patients than in control subjects (P< 0.05, respectively), while plasma IL-1 beta was similar among the 3 groups (P> 0.05, respectively). The SYNTAX score was positively related to NGAL (r = 0.363, P< 0.001), MMP-9 (r = 0.377, P< 0.001), and hs-CRP (r = 0.163, P< 0.011); the SYNTAX score was not related to IL-1 beta (r = -0.043, P = 0.510). Plasma NGAL was positively related to MMP-9 (r = 0.601, P< 0.001) and IL-1 beta (r = 0.159, P = 0.014). The area under the ROC curve for NGAL discriminating severe coronary stenosis was 0.838 (95% CI: 0.752-0.923, P< 0.001), which was greater than that for MMP-9 [0.818, (95% CI: 0.724-0.912, P< 0.001)], IL-1 beta [0.485, (95% CI: 0.369-0.601, P = 0.791)], and hs-CRP [0.607, (95% CI: 0.492-0.722, P = 0.061)]. Multivariate regression analysis showed that plasma NGAL levels were independently related to high SYNTAX scores [OR = 1.109, (95% CI: 1.104-1.114), P< 0.001]. Conclusion Plasma NGAL, MMP-9, and hs-CRP levels in STEMI patients were higher than those in the SAP patients and control subjects. NGAL had a better ability to discriminate severe coronary stenosis than MMP-9, IL-1 beta, and hs-CRP. NGAL may be a novel biomarker to aid in risk stratification in coronary heart disease patients.