The influence of gender and atopy in the relationship between obesity and asthma in childhood.
BACKGROUND
The objective of the study was to examine the relationship between asthma and overweight-obesity in Spanish children and adolescents and to determine whether this relationship was affected by gender and atopy.


METHODS
The study involves 8607 Spanish children and adolescents from the International Study of Asthma and Allergies in Childhood phase III. Unconditional logistic regression was used to obtain adjusted odds ratios (OR) and 95% confidence intervals (95% CI) for the association between asthma symptoms and overweight-obesity in the two groups. Afterwards, it was stratified by sex and rhinoconjunctivitis.


RESULTS
The prevalence of overweight and obesity in 6-7-year-old children was 18.6% and 5.2% respectively and in 13-14 year-old teenagers was 11.4% and 1.1% respectively. Only the obese children, not the overweight children, of the 6-7 year old group had a higher risk of any asthma symptoms (wheezing ever: OR 1.68 [1.15-2.47], asthma ever: OR 2.29 [1.43-3.68], current asthma 2.56 [1.54-4.28], severe asthma 3.18 [1.50-6.73], exercise-induced asthma 2.71 [1.45-5.05]). The obese girls had an increased risk of suffering any asthma symptoms (wheezing ever: OR 1.73 [1.05-2.91], asthma ever: OR 3.12 [1.67-5.82], current asthma 3.20 [1.65-6.19], severe asthma 4.83[1.94-12.04], exercise-induced asthma 3.68 [1.67-8.08]). The obese children without rhinoconjunctivitis had a higher risk of asthma symptoms.


CONCLUSIONS
Obesity and asthma symptoms were associated in 6-7 year-old children but not in 13-14 year-old teenagers. The association was stronger in non-atopic children and obese girls.