Gene polymorphism and serum levels of interleukin-18 in patients with coronary artery disease and type 2 diabetes mellitus

Background Circulating concentrations of interleukin-18 (IL-18) were shown to be correlated with the vascular events in patients with coronary artery disease (CAD). Objectives To assess the serum levels of IL-18 and its gene polymorphism in CAD and diabetic patients and correlate these findings with clinical, echocardiographic, laboratory, and coronary angiographic findings. Patients and methods This cross-sectional observational study included 180 patients, who were divided according to presence or absence of CAD and type 2 diabetes mellitus into four groups: group I (41 patients), nondiabetic patients without CAD; group II (51 patients), nondiabetic patients with CAD; group III (40 patients), diabetic patients without CAD; and group IV (48 patients), diabetic patients with CAD. Serum levels of IL-18 and its genotyping distributions were measured in all groups and correlated with the angiographic coronary scoring systems. Results Serum IL-18 level was higher significantly in patients with CAD (groups II and IV) than in patients without CAD (groups I and III) (P Conclusion IL-18 is a novel and independent risk factor for CAD, and it is associated with its extent and severity. IL-18 gene polymorphism at 137 G/C site could be a risk factor for development of CAD, presumably by increasing serum IL-18 levels. Individuals carrying the G allele and the G/G genotype of IL-18 have an increased risk to develop CAD.