Visness CM, London SJ, Daniels SJ, et al. J Allergy Clin Immunol. 2009;123(5):1163–1169, 1169.e1–1169.e4
PURPOSE OF THE STUDY. To study the association of obesity with total and allergen-specific immunoglobulin E (IgE) levels and allergy symptoms in children and adolescents.
STUDY POPULATION. A nationally representative survey of 4111 children 2 to 19 years of age enrolled in the 2005–2006 National Health and Nutrition Examination Survey.
METHODS. Eligible persons who completed both the household interview and medical examination components of the National Health and Nutrition Examination Survey and had height and weight measured were included in the study. Total serum IgE and allergen-specific IgE tests were performed depending on age. Atopy was defined as a positive response (≥0.35 kU/L) to ≥1 of the allergens tested. BMI was calculated for all study participants, and detailed questions regarding physical activity, household smoking, maternal smoking during pregnancy, and birth weight were asked.
RESULTS. Total serum IgE levels were higher among overweight and obese children versus normal-weight children, unrelated to smoking exposure, birth weight, or physical activity. The odds ratio for atopy was increased for the obese children, compared with normal-weight children. Most of the children with atopy were sensitized to foods, and there was no association seen between obesity and reported allergy symptoms and hay fever. There was a strong relationship between C-reactive protein levels and total IgE levels.
CONCLUSIONS. Overweight status in children is associated with allergic predisposition, especially to foods. Because childhood obesity continues to be an enormous health care concern facing US children, this increased risk of allergy is yet another motivating factor to combat childhood obesity.
REVIEWERS COMMENTS. The authors of this study attempted to correlate childhood obesity with increased atopy, particularly to foods. However, the definition of atopy relied on an elevated serum-specific IgE level, which may not be clinically relevant, especially for food allergy without clinical history. The study authors recognized that BMI is not the best measure of obesity because of larger bone structure and muscle mass in some children, which further confounds the classification of overweight and obese children. Studies also showed that underweight children had increased risk of atopic disease, but this was not addressed in this study. Any effort to reduce or to prevent childhood obesity is beneficial but, in terms of atopic diseases, maybe we should take the “3 bears” approach: not too skinny, not too fat; normal weight is perfect.
- Copyright © 2009 by the American Academy of Pediatrics