School-age obese asthmatic children have distinct lung function measures from lean asthmatics and obese children

Abstract

Background

The lung functions of children with obese asthma seem to be distinct from those of obese children or lean asthmatics.

Aim

To measure baseline lung function, exercise-induced bronchoconstriction (EIB), and bronchial hyperreactivity (BHR) in school-age obese asthmatics (OA group) and to compare the data with obese children (O group), lean asthmatics (A group), and healthy controls (H group).

Methods

One hundred seventy school-age children were enrolled in this prospective cross-sectional study. Baseline fractionated exhaled nitric oxide (FeNO), and baseline, post-exercise (post-E), and post-bronchodilation (post-BD) impulse oscillometry (IOS) and spirometry tests were performed. EIB and BHR were evaluated based on the difference (Δ) in post-E - baseline, and post-BD – baseline values.

Results

The mean FeNO level was higher in the OA group than in the other groups (p = 0.002). Baseline zR5 and R5-20 were higher (p = 0.013 and p = 0.044), but zFEF25-75 was lower (p < 0.01), in the OA group. ΔPost-E – baseline zFEV1 was lower in the A group (p = 0.003) but was higher in the OA group (p = 0.014) than the other groups. ΔPost-BD – baseline zFEV1 was lower in the H group compared to the other three groups (p = 0.004), but no significant difference was observed among the O, A, and OA groups (p > 0.05).

Conclusion

Higher airway inflammation (high FeNO), peripheral airway resistance (high zR5 and zR5-20) and a lower peripheral airway flow (low FEF25-75) were observed at baseline measurement in school-age obese asthmatics compared to lean asthmatics and obese children. Obese asthmatics had no EIB but exhibited a similar BHR to that of asthmatics.

Keywords:

• Asthma
• child
• fractional exhaled nitric oxide
• impulse oscillometry
• spirometry
• obesity
• pediatrics

Acknowledgment

The authors are indebted to specialist nurse Nuray Aydın for her work in the measurement of lung function and the care provided for the children, and to the children themselves, and their parents.

Declaration of interest

The authors have no conflicts of interest to declare.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.