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The relationship between respiratory system impedance and lung function in asthmatics: A prospective observational
Takahiro Kamada1, Masahiro Kaneko1, Hiromi Tomioka1
1Department of Respiratory Medicine, Kobe City Medical Center West Hospital, Kobe, Japan.
Respiratory Physiology & Neurobiology
|February 13, 2017
Summary
Annual changes in respiratory system resistance, measured by forced oscillation technique (FOT), significantly correlate with lung function changes in asthma patients. This suggests FOT parameters can help assess asthma progression.
Area of Science:
- Respiratory Medicine
- Pulmonology
- Medical Technology
Background:
- Asthma management requires accurate monitoring of lung function.
- Forced oscillation technique (FOT) measures respiratory system impedance.
- Understanding FOT parameter changes in relation to lung function is crucial for asthma assessment.
Purpose of the Study:
- To investigate the relationship between annual changes in respiratory system impedance (measured by FOT) and standard lung function tests in asthma patients.
- To determine if FOT parameters can serve as reliable indicators of lung function changes over time in asthma.
Main Methods:
- Recruited asthma outpatients from March 2011 to March 2012.
- Conducted lung function tests and FOT every 6 months until March 2016.
- Analyzed the relationships between annual parameter changes in 64 patients over a median follow-up of 55 months.
Main Results:
- At enrollment, respiratory reactance showed moderate correlations with parameters like X5, Fres, and ALX.
- Annual changes in airway resistance at 5Hz (R5) demonstrated a strong and significant association with changes in forced expiratory volume in one second (%FEV1).
- The correlation between annual R5 change and %FEV1 change was r=-0.564 (r²=0.318, p<0.001).
Conclusions:
- Longitudinal changes in airway resistance and reactance, as measured by FOT, are potentially valuable for assessing lung function in asthma patients.
- FOT offers a non-invasive method to track respiratory impedance changes relevant to asthma progression.
- These findings support the utility of FOT in the clinical management of asthma.
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