Correlations of forced oscillometric bronchodilator response with airway inflammation and disease duration in asthma

概要

1

Correlations of forced oscillometric bronchodilator response with airway
inflammation and disease duration in asthma

Naoko Higaki 1, Hiroshi Iwamoto 1*, Kakuhiro Yamaguchi 1, Shinjiro Sakamoto 1, Yasushi
Horimasu 1, Takeshi Masuda 1, Shintaro Miyamoto 1, Taku Nakashima 1, Shinichiro Ohshimo
2
1

, Kazunori Fujitaka 1, Hironobu Hamada 3, Noboru Hattori 1
Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health

Sciences, Hiroshima University, Hiroshima, Japan
2

Department of Emergency and Critical Care Medicine, Graduate School of Biomedical and

Health Sciences, Hiroshima University, Hiroshima, Japan
3

Department of Physical Analysis and Therapeutic Sciences, Graduate School of Biomedical

and Health Sciences, Hiroshima University, Hiroshima, Japan

*Corresponding author:
Hiroshi Iwamoto, Department of Molecular and Internal Medicine, Graduate School of
Biomedical and Health Sciences, Hiroshima University
1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
E-mail address: iwamotohiroshig@gmail.com
Phone: +81-82-257-5196

Fax: +81-82-255-7360

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Abstract
Introduction: Airway resistance and reactance, measured by forced oscillometry, are used to
measure airway obstruction in patients with asthma.
Objectives: This study aimed to investigate oscillometric bronchodilator responses in treated
and untreated asthma and evaluate its association with airway inflammation and disease
duration.
Methods: This study included 30 non-smoking patients with mild to moderate treated
asthma, 25 patients with newly diagnosed untreated asthma, and 29 control subjects.
Spirometric and oscillometric measurements were performed before and after inhalation of
400 µg salbutamol. Disease duration was defined as the number of years since asthma
diagnosis.
Results: At airway resistance of 5 Hz (R5) and 20 Hz (R20), bronchodilator responses in
patients with untreated and treated asthma were greater than those in control subjects. In
patients with untreated asthma, higher fractional exhaled nitric oxide concentration (FeNO)
levels were strongly correlated with greater reversibility of R20 (rs=-0.621, p<0.001). In
patients with treated asthma, there was no significant association between FeNO and
oscillometric reversibility, whereas longer disease duration was significantly associated with
lesser bronchodilator response at R20 (rs=0.441, p<0.05). Treated asthma patients with longer
disease duration (≥10 years) showed significantly higher post-bronchodilator R5 and R20
than treated asthma patients with shorter disease duration (<10 years).
Conclusion: The present study provides further evidence of an association between airway
inflammation and variable airway obstruction in asthma patients and indicates that long-term
disease duration could be related to poorly reversible airway resistance in patients with mild
to moderate asthma.