ABSTRACT
<p><b>OBJECTIVE</b>To study the association between gender and lung function in obese asthmatic children before and after inhaling corticosteroids (ICS).</p><p><b>METHODS</b>A total of 102 asthmatic boys (including 57 normal-weight and 45 obese boys) and 88 asthmatic girls (including 46 normal-weight and 42 obese girls) received ICS treatment for one year. Pulmonary functions were evaluated before and after the treatment for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), maximal expiratory flow 25 (MEF25) and maximal expiratory flow 50 (MEF50).</p><p><b>RESULTS</b>The asthmatic children in the 4 subgroups showed similar pulmonary functions before the treatment. After inhalation of methacholine, FVC% and FEV1% were improved in both normal-weight boys and normal-weight girls; FVC% and FEV1% in obese boys were improved after the treatment, but the obese girls showed improvement only in FVC%.</p><p><b>CONCLUSION</b>Inhalation of methacholine can improve large airway function in asthmatic children, and gender affects the improvement to a lesser extent in normal-weight children. In obese asthmatic children, methacholine inhalation better improves lung functions in boys than in girls.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To study the association between body mass index (BMI) and lung function of asthmatic children after inhaling corticosteroids (ICS).</p><p><b>METHODS</b>One hundred and fifty-seven children with asthma were classified into obese (46 cases), over-weight (50 cases) and normal-weight groups (61 cases) based on BMI. All of the children received ICS for one year. Pulmonary functions were evaluated before and after treatment. Large airway function includes forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%). Small airway function includes maximal expiratory flow 25 (MEF25%) and maximal expiratory flow 50 (MEF50%).</p><p><b>RESULTS</b>The bronchial provocation test before treatment showed that the decline rate of pulmonary function (FVC%, FEV1%, MEF25% and MEF50%) in the obese group was higher than the normal-weight group after methacholine inhalation. After salbutamol inhalation, the improvement rate of the large airway (FVC%) and small airway (MEF25% and MEF50%) functions in the obese group was lower than the normal-weight group, and the improvement rate of small airway (MEF25% and MEF50%) function in the over-weight group was lower than in the normal-weight group. After treatment with ICS for one year, large airway function (FVC% and FEV1%) in the normal-weight group was higher than pre-treatment, however only FVC% in the normal-weight and obese groups was higher than pre-treatment. There was no significant difference in small airway function before and after treatment in all three groups.</p><p><b>CONCLUSIONS</b>Obesity can increase the sensitivity to methacholine and restrain the sensitivity to tosalbutamol in children with asthma. ICS can improve the large airway function in asthmatic children with normal body weight, but has no effect on small airway function. Obesity can restrain the effect of ICS on asthmatic children.</p>