Associations between circulating full-length angiopoietin-like protein 8 levels and severity of coronary artery disease in Chinese non-diabetic patients: a case-control study

Background: Angiopoietin-like protein 8 (ANGPTL8), which is a novel hormone produced in liver and adipose tissue, is involved in regulating lipid metabolism. Patients with diabetes and coronary artery disease (CAD) have remarkably higher levels of ANGPTL8 than those with only diabetes. However, no studies have investigated the involvement of ANGPTL8 in CAD in Chinese non-diabetic individuals. Therefore, we investigated full-length circulating ANGPTL8 levels in patients with CAD and the association between ANGPT8 levels and severity of CAD in Chinese individuals without diabetes. Methods: We performed a case-control study in 149 Chinese non-diabetic subjects, including 80 patients with CAD and 69 controls. The Gensini stenosis scoring system was used to assess the severity of CAD. Circulating full-length ANGPTL8 levels were measured by an enzyme-linked immunosorbent assay kit. The associations between circulating full-length ANGPTL8 levels and CAD were determined by multivariate logistic regression analysis. The association between ANGPTL8 levels and Gensini scores was determined by multivariate linear regression analysis. Results: Circulating full-length ANGPTL8 levels were significantly higher in Chinese non-diabetic patients with CAD compared with controls (665.90 +/- 243.49 vs 462.27 +/- 151.85 pg/ml, P <0.001). After adjusting for confounding factors, we found that circulating full-length ANGPTL8 levels were an independent risk factor for CAD (odds ratio = 2.002/100 pg ANGPTL8, 95% CI 1.430-2.803, P <0.001) and circulating ANGPTL8 levels were positively associated with the Gensini score (beta = 5.701/100 pg ANGPTL8, 95% CI 1.306-10.096, P=0.012). Conclusions: This study shows that the circulating ANGPTL8 levels are significantly increased in patients with CAD compared with controls in Chinese non-diabetic individuals. Circulating full-length ANGPTL8 levels are an independent risk factor for CAD and they are positively associated with the severity of CAD.