Effects of Body Mass on Bronchial Hyperresponsiveness and Atopy in Childhood Asthma

Lee, Seung Hun; Baek, Nam Kyung; Kang, Im Ju

Abstract

PURPOSE: For the past two decades, there has been a significant increase in the prevalence of both asthma and obesity. Obesity may be associated with increasing childhood asthma and atopy. So, we performed this study to know the effects of body mass on bronchial hyperresponsiveness (BHR) and atopy in childhood asthma.
METHODS
The subjects were, 340 children aged 6-15 years with asthma, visited the Pediatric Outpatient Clinic. There, their heights and, weights were measured and they underwent, pulmonary function tests (PFT), BHR to methacholine and skin prick tests. After determining body mass index (BMI), they were divided into four groups by BMI percentile curve based on gender and age (underweight < or =15th percentile, normal weight 15.1-85th percentile, overweight 85.1th-95th percentile, obesity > or =95.1th percentile). Atopy, allergen sensitization, BHR, respiratory symptoms, PFT were compared between each group.
RESULTS
In all subjects, there were 70 (20.6%) and 73 (21.5%) cases in the overweight and obese groups, respectively. Increasing BMI was significantly associated with a higher prevalence of snoring,(P=0.004) wheezing in the perceding three months (P=0.002) and BHR- positive,(P=0.003) but not atopy.(P=0.075) Among the groups classified by BMI percentile, there were significant differences in FEV1 and FEV1/FVC.(P=0.027, P=0.033) Being overweight and/or, obese were significant risk factor for BHR, though only among females (OR 5.1; 95% CI 1.6-16.5, 4.9; 1.8-13.4) not male (OR 1.1; 95% CI 0.5-2.1, OR 1.7; 95% CI 0.7-2.0).
CONCLUSION
Among girls, a higher BMI might be a risk factor for BHR. Higher BMI is not associated with atopy on either boys or girls.