Interleukin-18 promoter −137 G/C polymorphism (rs187238) is associated with biochemical markers of renal function and cardiovascular disease in type 2 diabetes patients

[Display omitted] •Association between −137G/C IL-18 gene polymorphism and cardiovascular disease in T2DM Brazilian population.•An increased IL-18 production in carriers of CC −137 genotype for the −137G/C polymorphism compared to the GG or GC carriers.•High creatinine and albuminuria levels were associated with CC −137 genotype. Interleukin-18 (IL-18), a proinflammatory and proatherogenic cytokine, has been associated with type 2 diabetes, metabolic syndrome, stroke and coronary artery disease. Some studies have indicated that the IL-18 promoter −137 G/C polymorphism seems to be associated with changes in the IL-18 expression and may contribute to the development of cardiovascular disease (CVD). The aim of this study was to evaluate the association between −137 G/C polymorphism and the levels of IL-18, biochemical markers for cardiovascular disorders, anthropometric profile and cardiovascular disease in Brazilian patients with type 2 diabetes (T2DM). Design & Methods. Study subjects comprised 125 T2DM patients undergoing follow-up at a reference endocrinology service in northeastern Brazil. The −137G/C polymorphism in the IL-18 gene and serum IL-18 levels were determined by using allele-specific polymerase chain reaction (PCR) and enzyme-linked immune assay (ELISA), respectively. The anthropometric parameters were assessed using a Body Composition Monitor with Scale, and the laboratory data were measured using an automatic analyzer as well as spectrophotometric analysis. Results. The genotype distribution of IL-18 –137 G/C genetic polymorphism was significantly different among T2DM patients with and without CVD. The results show an association between the CC genotype of −137G/C polymorphism and CVD in T2DM patients (p