Methods：Eleven obese children (9 boys and 2 girls) from 8 to 15 years of age were enrolled in this study. 3 of them were hospitalized for more over 3months and the others were outpatients for 6 months. Eight had no asthma and 2 of them had asthma in mild intermittent severity without need of controller medications. Spirometry and two forced oscillation technique (FOT) tests (MostGraph® and Master Screen IOS®) were performed to assess lung function before and after treatment of obesity (diet and exercise). Patients were divided into two groups, the success group (n=5) and the failure group (n=6), based on outcome in weight loss. Success was defined as more than 10% improvement in percentage of overweight (POW) in the observation period.
Results: In FOT, R5-R20, resonant frequency (Fres), reactance area (AX) (IOS®) and R5, Fres (MostGraph®) were significantly improved in the success group, not in the failure group. As previously reported, FEV1.0% was improved significantly in the success group, not in the counterpart.
Conclusions: Respiratory function, not only FEV1 but reactance and resistance parameters in FOT, was improved in parallel with weight loss in obese children, which may implicate functional relationship between obesity and asthma.