Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control.

Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control.

Clin Exp Allergy. 2017 Sep 21;:

Authors: Heijkenskjöld-Rentzhog C, Janson C, Berglund L, Borres MP, Nordvall L, Alving K, Malinovschi A

Abstract
BACKGROUND: Classic spirometry is effort-dependent and of limited value in assessing small airways. Peripheral airway involvement, and relation to poor control, in asthma, has been highlighted recently. Forced oscillation technique (FOT) offers an effort-independent assessment of overall and peripheral lung mechanics. We studied the association between lung function variables, obtained either by spirometry or multi-frequency (5, 11 and 19 Hz) FOT, and asthma diagnosis and control.
METHODS: Spirometry measures, resistance at 5 (R5) and 19 Hz (R19), reactance at 5 Hz (X5), resonant frequency (fres ), resistance difference between 5-19 Hz (R5-R19) and Asthma Control Test scores were determined in 234 asthmatic and 60 healthy subjects (aged 13-39 years). We used standardised lung function variables in logistic regression analyses, unadjusted and adjusted for age, height, gender, weight.
RESULTS: Lower FEV1 /FVC (OR (95% CI) 0.47 (0.32, 0.69)) and FEF50 (0.62 (0.46, 0.85)) per standard deviation increase, and higher R5 (3.31 (1.95, 5.62)) and R19 (2.54 (1.65, 3.91)) were associated with asthma diagnosis. Independent predictive effects of FEV1 /FVC and R5 or R19, respectively, were found for asthma diagnosis. Lower FEV1 /FVC and altered peripheral FOT measures (X5, fres and R5-R19) were associated with uncontrolled asthma (p-values < 0.05).
CONCLUSIONS: Resistance FOT measures were equally informative as spirometry, related to asthma diagnosis, and furthermore, offered additive information to FEV1 /FVC, supporting a complementary role for FOT. Asthma control was related to FOT measures of peripheral airways, suggesting a potential use in identifying such involvement. Further studies are needed to determine a clinical value, and relevant reference values in children, for the multi-frequency FOT measurements. This article is protected by copyright. All rights reserved.

PMID: 28940832 [PubMed - as supplied by publisher]

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