Increased expression of serum IL-18 and IL-18R in newly diagnosed type 2 diabetes mellitus

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a heterogeneous metabolic disorder in which genetic, sedentary lifestyle, obesity, and environmental factors come together to produce insulin resistance in target tissues, leading to hy-perglycemia. Evidence reveals that inflammation may play an essential role in the pathogenesis of T2DM. Interleukin-18 (IL-18), a proinflammatory cytokine, plays a crucial role in the acute and chronic inflammatory process. The association of IL-18 levels with IL-18R expression in T2DM has not been investigated so far. The aim of this study was to compare the peripheral changes in serum IL-18 levels and its receptor (IL18R) expression in newly diagnosed T2DM and healthy controls. METHODS: A total of 35 newly diagnosed type 2 diabetic cases and 35 non-diabetic controls were enrolled after obtain-ing informed consent. Venous whole blood was taken under aseptic conditions. Biochemical parameters were estimated in an auto-analyzer. Serum IL-18 levels were calculated using ELISA, whereas IL-18R expression was determined via RT-PCR. GAPDH was used as an internal control. RESULTS: When compared to non-diabetic controls, the serum IL-18 levels were significantly higher in T2DM patients (P=0.010) along with a significant upregulation of IL18R (P=0.0018). Serum IL-18 levels in T2DM and non-diabetic controls were 669.5 (445) and 498.3 (404.9) pg/mL respectively, and IL-18R showed a fold change of 10.33. CONCLUSIONS: Both serum IL-18 and its receptor IL-18R is significantly higher in newly diagnosed T2DM patients.