title: Effects of indacaterol versus tiotropium on respiratory mechanics assessed by the forced oscillation technique in patients with chronic obstructive pulmonary disease.
abstract: The forced oscillation technique (FOT) can measure respiratory mechanics and has attracted attention in chronic obstructive pulmonary disease (COPD). We aimed to evaluate the effects of only indacaterol and tiotropium monotherapies on airflow limitation and respiratory impedance. Pulmonary function tests, COPD assessment test (CAT), and multifrequency FOT with MostGraph-01 were performed at the beginning and after 8 weeks of treatment with indacaterol or tiotropium. The resistance index, resistance at 5 Hz (R5), resistance at 20 Hz (R20), reactance index, reactance at 5 Hz (X5), resonant frequency (Fres), and low-frequency reactance area (ALX) were determined at whole-breath, inspiratory, and expiratory phases. Eighty-two patients (mean age: 73 years; mean forced expiratory volume in 1 second (FEV1): 61.6%±19.0% predicted) were randomized to indacaterol or tiotropium treatment. Both bronchodilators improved airflow limitation, with mean trough improvements in FEV1 of 165 mL and 80 mL in the indacaterol and tiotropium groups, respectively. The CAT score decreased in the indacaterol group (P<0.001; 11.2±6.6 to 7.5±5.6). Compared with tiotropium, indacaterol significantly improved FEV1, percent predicted FEV1, and CAT score (P=0.042, P=0.008, and P=0.027, respectively). For respiratory impedance, indacaterol and tiotropium changed R5, X5, Fres, and ALX at whole-breath, inspiratory, and expiratory phases. In the indacaterol group, the changes in R5, R5-R20, X5, Fres, and ALX were significantly correlated with the changes in FEV1. The use of the FOT may enable the evaluation of the effects of bronchodilators in addition to FEV1-indicated therapeutic effects in COPD.
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan ; Department of Clinical Pharmacology and Therapeutics, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Inui
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Sayomi
authors.initials: S
authors.lastname: Matsushima
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Shinpei
authors.initials: S
authors.lastname: Kato
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yasui
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kono
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Enomoto
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Department of Respiratory Medicine, Hamamatsu Rosai Hospital, Shougen-cho, Hamamatsu, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Toyoshima
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D000403:Airway Resistance / Q000187:drug effects; D001993:Bronchodilator Agents / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007189:Indans / Q000009:adverse effects / Q000627:therapeutic use*; D007564:Japan; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D009991:Oscillometry; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D015363:Quinolones / Q000009:adverse effects / Q000627:therapeutic use*; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics / Q000187:drug effects*; D013997:Time Factors; D000069447:Tiotropium Bromide / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014797:Vital Capacity
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D001993:Bronchodilator Agents; D007189:Indans; D018727:Muscarinic Antagonists; D015363:Quinolones; C510790:indacaterol; D000069447:Tiotropium Bromide
keywords: MostGraph-01; chronic obstructive pulmonary disease; forced oscillation technique; indacaterol; monotherapy; reactance; resistance; tiotropium