Mediators of inflammation in children with type I diabetes mellitus: cytokines in type I diabetic children

Objectives: Recent evidence favors primary role of cellular autoimmunity and its humoral mediators in pathogenesis and following Type I diabetes mellitus (DM). The present study was carried out to investigate serum concentrations of C-reactive protein (CRP), interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)- in children with type I DM. Potential role of lipid metabolism, glycemic control, body mass index (BMI) and disease duration were evaluated.

Design and methods: Thirty-five children with type I DM and 30 age and gender matched nondiabetic controls were recruited for this study.

Results: Circulating IL-8 levels were elevated in children with type I DM (12.7 ± 1.7 pg/mL) compared with nondiabetic controls (5.5 ± 0.3 pg/mL) and the difference remained significant after adjustment for cofactors and covariates (p: 0.033). Although statistically insignificant serum CRP concentrations were slightly higher in diabetic children (p: 0.075). Serum TNF- and IL-6 levels were comparable in diabetic and nondiabetic groups. However newly diagnosed (<1 yr) cases had higher TNF- and IL-6 levels compared to cases with longer standing DM.

In diabetic children BMI was independently associated with an increase in serum IL-8 levels. Serum CRP, lipids, apolipoproteins and glycemic control were not significant predictors of cytokine concentrations in children with type I DM.

Conclusion: Circulating levels of IL-8 were elevated and were correlated with BMI in children with type I DM, hinting perhaps at adipose tissue as a site of production. Elevated systemic IL-6 and TNF- were limited to newly diagnosed cases suggesting activation of the inflammatory immune response system at early stages of the disease.