Association between Asthma and Body Mass Index in Children

Obesity has been reported to be associated with an increase in asthma in children. If there is any association, it could be attributed to an effect of obesity on lung volume and thus airway's obstruction. Data from 2413 children aged 7-12 years in Isfahan were analyzed. The subjects were included in this study if data were available for: height, weight, age, lung volume, and any measure of asthma, including history of diagnosed asthma, wheeze, chronic cough, and medication as obtained by questionnaire. Body mass index (BMI) percentiles, divided into quintiles per year age, were used as a measure of standardized weight.After adjusting for, sex, age, smoking and family history, BMI was a significant risk factor for wheeze ever (p = 0.000) and asthma ever (p = 0.000), diagnosed asthma (P=0.000) and current asthma (p = 0.000). There was no significant correlation between BMI and obstructive spirometry. Increased BMI was significantly associated with an increased airway resistance.Despite the fact that higher BMI is a risk factor for, wheeze ever, wheeze and dyspnea in the last 12 months, and diagnosed asthma, higher BMI is not a risk factor for obstructive pattern in pulmonary function test.