Inhomogeneity of lung ventilation in children with obesity and its potential role in worsening asthma

<p dir="ltr">Asthma is more frequent and severe in individuals with obesity compared to those with normal weight. While inhomogeneity of lung ventilation due to distal airway obstruction is a key feature in asthma, the effect of obesity on ventilation homogeneity is unclear. We conducted a cross‐sectional study comparing lung clearance index (LCI) using multiple breath nitrogen washout technique between children with normal weight and asthma (<i>n</i> = 97), overweight/obesity and asthma (<i>n</i> = 100), overweight/obesity and no asthma (<i>n</i> = 100), and children with normal weight and no asthma (<i>n</i> = 67). Spirometry, lung volumes, and fractional exhaled nitric oxide (FeNO) were obtained for comparison. Results showed no significant difference in LCI between overweight/obesity groups and normal weight groups and no significant correlation between LCI and body mass index (BMI). However, LCI was higher in the asthma groups compared to non‐asthma groups (<i>p</i> = 0.017, <i>p</i> = 0.003). There was a significant negative correlation between LCI and FEV1% predicted, FEV1/FVC, and FEF25–75% predicted (<i>r </i>= −0.24, <i>p</i> < 0.001; <i>r </i>= −0.26, p< 0.001; r = −0.23, <i>p</i> < 0.001), and a positive correlation with RV/TLC (<i>r</i> = 0.17, p = 0.003) and FeNO (<i>r</i> = 0.29, <i>p</i>< 0.001). These findings indicate that obesity does not affect the homogeneity of lung ventilation. Therefore, alternative mechanisms should be considered to explain the association between asthma and obesity.</p><h2>Other Information</h2><p dir="ltr">Published in: Physiological Reports<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.14814/phy2.70257" target="_blank">https://dx.doi.org/10.14814/phy2.70257</a></p>