Identifying Treatable Trait of Dynamic Hyperinflation in Adults Living With Asthma Using the Glittre-ADL Test

Dynamic hyperinflation (DH) is a treatable trait that impairs activities of daily living in adults living with asthma (alwA) and should therefore be detected early. We aimed to identify DH in alwA using the Glittre-ADL test (TGlittre) and, secondarily, to assess the association of DH with small airway dysfunction (SAD) and quality of life (QoL).

Cross-sectional study in which 41 alwA underwent the TGlittre coupled with dynamic ventilation measurement, with detection of DH using inspiratory capacity (∆IC). They also underwent spirometry, impulse oscillometry (IOS), and the Mini-Asthma Quality of Life Questionnaire (Mini-AQLQ).

In TGlittre, 19 participants presented DH at the end of the test (DH group), while 22 did not (NDH group). Although participants in the DH group took longer to complete the TGlittre tasks, there were no statistical differences between the 2 groups (269.9 ± 77.1% vs. 260.1 ± 73.8% predicted, p = 0.68). While the DH and NDH groups did not show significant differences in any of the spirometric parameters, these two groups differed in various IOS parameters, with higher values for frequency response (Fres, p = 0.037) and heterogeneity of resistance between 5 and 20 Hz (R5-R20, p = 0.003) in the DH group. Although ∆IC did not show significant correlations with either spirometric or Mini-AQLQ parameters, there were several significant correlations with IOS parameters. In the multiple linear regression, Fres and R5-R20 explained 51% of IC variability.

In alwA, the TGlittre is able to detect DH in about half of the cases. Having HD does not have a negative impact on performance during TGlittre. However, there is an association between DH and SAD. Since DH can be detected even in individuals with normal spirometry and/or good performance during the TGlittre, it may be interesting to incorporate the assessment of ventilatory dynamics during the TGlittre in alwA.