Association of obesity with IgE levels and allergy symptoms in children and adolescents: Results from the National Health and Nutrition Examination Survey 2005-2006

Background: The prevalence of both obesity and allergic disease has increased among children over the last several decades. Previous literature on the relationship between obesity and allergic disease has been inconsistent. It is not known whether systemic inflammation could be a factor in this relationship. Objective: We sought to examine the association of obesity with total and allergen-specific IgE levels and allergy symptoms in US children and adolescents and to assess the role of C-reactive protein. Methods: National Health and Nutrition Examination Survey data from 2005-2006 included measurement of total and allergen-specific IgE levels and allergy questions. Overweight was defined as the 85th or greater to less than the 95th percentile of body mass index for age, and obesity was defined as the 95th percentile or greater. Linear and logistic regression models were used to examine the association of weight categories with total IgE levels, atopy, allergen-specific IgE levels, and allergy symptoms among youth aged 2 to 19 years. Results: Geometric mean total IgE levels were higher among obese (geometric mean ratio, 1.31; 95% CI, 1.10-1.57) and overweight (ratio, 1.25; 95% CI, 1.02-1.54) children than among normal-weight children. The odds ratio (OR) for atopy (any positive specific IgE measurement) was increased in the obese children compared with that seen in those of normal weight; this association was driven largely by allergic sensitization to foods (OR for atopy, 1.26 [95% CI, 1.03-1.55]; OR for food sensitization, 1.59 [95% CI, 1.28-1.98]). C-reactive protein levels were associated with total IgE levels, atopy, and food sensitization. Conclusions: Obesity might be a contributor to the increased prevalence of allergic disease in children, particularly food allergy. Systemic inflammation might play a role in the development of allergic disease. (J Allergy Clin Immunol 2009;123:1163-9.)