Association between Body Mass Index Status and Childhood Asthma Control.

Background: The association between body mass index (BMI) status and childhood asthma control is not well understood. The aim of this study was to explore the association between BMI status and childhood asthma control. Methods: Two hundred forty-two children, aged 6-11 years, with asthma were included. The outcome variables were asthma control levels assessed by the Chinese version of the childhood asthma control test (C-ACT), asthma-related hospitalizations or emergency department (ED) visits in the past 12 months, and forced expiratory volume in 1 second (FEV1) as a percentage of the predicted value. The associations between BMI status (underweight, overweight, or obese, relative to normal weight) and the three outcome variables were estimated by ordinal logistic regression, binary logistic regression, and multiple linear regression analyses. Results: No significant association was found between BMI status and asthma control levels assessed by C-ACT, and between BMI status and asthma-related hospitalizations or ED visits in the past 12 months, after adjustment for age, sex, father's education level, mother's education level, per capita family monthly income, medical insurance, passive smoking, allergic rhinitis, course of disease, and medication compliance. A significant association between underweight and FEV1 as a percentage of the predicted value was found after adjustment for the above covariates. However, no significant association between overweight or obese and FEV1 as a percentage of the predicted value was found. Conclusions: This study shows that BMI status may not be associated with childhood asthma control. Given the inconsistency in current evidence, more studies are needed in the future to investigate this association.