A novel approach to childhood obesity: circulating chemokines and growth factors as biomarkers of insulin resistance.

BACKGROUND: Insulin resistance (IR) in children with obesity constitutes a risk factor that should be precisely diagnosed to prevent further comorbidities. OBJECTIVE: Chemokines were evaluated to identify novel predictors of IR with clinical application. METHODS: We analysed the levels of cytokines (tumour necrosis factor [TNF] α and interleukins [ILs] 1ß, 4, 6 and 10), chemokines (stromal cell derived factor 1α, monocyte chemoattract protein [MCP] 1, eotaxin and fractalkine) and growth factors (brain-derived neurotrophic factor, pro-fibrotic platelet-derived growth factor [PDGF-BB] and insulin-like growth factor 1) in serum of prepubertal children with obesity (61 girls/59 boys, 50% IR and 50% non-IR) and 32 controls. Factor analysis, correlation, binary logistic regression and receiver operating characteristic analysis of combined biomarkers were used to validate their capability for preventive interventions of IR. RESULTS: Changes in MCP1, eotaxin, IL1ß and PDGF-BB were observed in IR children with obesity. Bivariate correlation between stromal cell derived factor 1α, MCP1, eotaxin, TNFα, brain-derived neurotrophic factor and/or PDGF-BB explained the high variance (65.9%) defined by three components related to inflammation and growth that contribute towards IR. The combination of leptin, triglyceride/high-density lipoprotein, insulin-like growth factor 1, TNFα, MCP1 and PDGF-BB showed a sensitivity and specificity of 93.2% for the identification of IR. The percentage of correct predictions was 89.6. CONCLUSIONS: Combined set of cytokines, adipokines and chemokines constitutes a model that predicts IR, suggesting a potential application in clinical practice as biomarkers to identify children with obesity and hyperinsulinaemia.