[Impact of obesity on response to therapy and pulmonary function in children with asthma]

To investigate the effects of obesity on response to therapy and pulmonary function in children with asthma who receive inhaled corticosteroid (ICS) treatment.

A total of 129 children with asthma were divided into two groups according to their body mass index: normal weight group (n=64) and obese group (n=65). The asthma control status and pulmonary function were compared between the two groups after one year of ICS treatment. The pulmonary function was expressed as percent forced expiratory volume in 1 second (FEV1%), percent predicted forced vital capacity (FVC%), peak expiratory flow (PEF), peak expiratory flow at 25% of vital capacity (PEF25), and peak expiratory flow at 50% of vital capacity (PEF50). The asthma control status was expressed as complete control rate, partial control rate, and uncontrolled rate. Sixty-eight healthy children were selected as the healthy control group.

There were significant differences in the indices of pulmonary function between the three groups before treatment (P<0.01); the healthy control group had the best values of pulmonary function, while the obese group had the worst values. After 1 year of treatment, the normal weight group showed significantly more improvements in FEV1% and FVC% than the obese group (P<0.01). However, there were no significant differences in improvements in PEF, PEF25, and PEF50 between the two groups. The complete control rate, partial control rate, and uncontrolled rate in the normal weight group were 72%, 19%, and 9%, respectively, while the rates in the obese group were 28%, 51%, and 22%, respectively; the normal weight group had a significantly better asthma control status than the obese group (P<0.01).

The asthmatic children with obesity have a significantly less improvement in large airway function and a poorer asthma control status after ICS treatment than those with the normal weight.