Relation of body mass index with IgE levels, allergic sensitization and lung function in asthmatic children: our experience and revision of literature

In recent decades, there has been an increase in the prevalence of asthma and obesity in pediatric age. In this regard several studies have provided controversial data to demonstrate the link between Body Mass Index (BMI) and asthma, both in adults and in children. In this prospective study we evaluated the relationship between body mass index value, total IgE immunoglobulin E levels, skin prick test (SPT) sensitization and lung function in children affected by asthma. According to the analysis of data on the comparison of normal-weight patients versus overweight/obese patients, there was no significant difference in the values of FEV1 (86%±12 vs 90% ± 19), FVC (81% ± 11 vs 88% ± 18), skin prick tests (22.72% vs 36.66%) and total IgE values (192.22±368.28 vs 503±914.04). We carried out a sub-analysis to study the difference between three groups of patients: normal weight, overweight and obese. Obese patients showed higher total IgE values than normal-weight patients with a statistically significant difference. Conversely, there was no significant difference between the normal weight group and the obese group in the respiratory function tests and the SPT. Moreover, we found a higher value of total IgE in female overweight/obese compared with normal weight, while there was no significant difference in relation to parameters of lung function and SPT. However, the same analysis in the male sample did not show any statistically significant difference. This study confirms the higher incidence of atopy in obese children, especially in female gender, but not a direct relationship with either allergens sensitization or abnormal lung function