Background. It has not clear in prepubertal children how cytokines, body mass, as well as asthma condition are interrelated. The aim of this study was to explore the relation between circulating levels of some cytokines with body mass index, local inflammation and symptoms manifestation in asthmatic and non asthmatic children in a longitudinal study. Material and methods. From a cohort of 50 obese adolescents (30 asthmatics (A) and 20 non-asthmatic (NA)) who was subjected to a program with nutritional counseling to reduce weight, we assessed the possible interaction between BMI and asthma in the systemic inflammatory response (cytokines proinflamatiorias), pulmonary function, nitric oxide in exhaled air and symptoms manifestation. The analysis was carried out using repeated measures mixed model. Results. The Th1 and Th2 responses were higher in asthmatic patients than in non-asthmatics (IL2: A = 1.35 vs NA = 0.77 ug / dl; IL6:. A = 0.49, 0.30). IL6 increased as BMI increased, showing a significant interaction between obesity and asthma. A relationship between blood concentrations of IL6 and lung function (FEV1) and FENOx (negative and positive respectively) was observed, being higher in asthmatic patients than no asthmatic, opposite relationship between blood IL2 concentrations and lung function (FEV1 ) and FENOx (positive and negative respectively) was observed being higher in asthmatics than non-asthmatics. Symptoms were major in obesity group with asthma.

Conclusions. Obesity may be a low-grade systemic inflammatory disease It is probable that part of the systemic inflammatory response has a direct effect on the local inflammatory response from a chronic inflammatory state. The Th1 response may play an important role in this mechanism.