Study of interleukin-18 ( IL18 ) and high sensitive C - reactive protein ( CRP ) in type 2 diabetes ( T2D ) with or without obesity

Background: Both diabetes and obesity are associated with chronic low-grade inflammation. IL-18 is a cytokine that stimulates various cell types and has pleiotropic functions. It is elevated in obesity, metabolic syndrome and type 2 diabetes (T2D). Aim of study: to test the hypothesis that serum level of IL-18 and high sensitive C-reactive protein can be used as markers for presence of chronic low-grade inflammation in type 2 diabetes more than in obesity per se. Subjects and methods: The study recruited 80 subjects. They comprised 20 diabetic obese cases (DM-OB group), 20 diabetic non-obese cases (DM-NOB group), : 20 non-diabetic obese cases (NDM-OB group) and 20 non-diabetic non-obese subjects (NDM-NOB group). All participants were submitted to careful history taking, through clinical investigations and laboratory assessment Results: hs-CRP was significantly highest in DMOB group (3.4±0.5 mg/dl) followed by NDM-OB group (2.9±0.4 mg/dl) followed by DM-NOB group (2.3±0.3 mg/dl) and least in NDM-NOB (0.8±0.3 mg/dl). Also, it was found that serum IL-18 was significantly highest in DMOB group (397.8±33.9 pg/mL) followed by NDM-OB (368.8±26.7 pg/mL) group followed by DM-NOB group (335.9±18.4 pg/mL) and least in NDM-NOB group (281.1±22.9 pg/mL). Serum IL-18 levels are directly correlated with BMI, waist circumference, hip circumference and waist/hip ratio in all the studied groups and with HbA1c in the diabetic groups. Conclusions: Serum IL-18 and hs-CRP are related to diabetes and obesity. They are associated with dyslipidemia, poor glycemic control, insulin resistance and impaired liver and renal functions.