PURPOSE: Combination inhaled corticosteroid/long acting bronchodilator (ICS/LABA) therapy reduces the exacerbation rate and improves spirometry and quality of life in COPD. Forced oscillation technique (FOT) is used to measure small airway function. We hypothesized that ICS/LABA therapy improves small airway function.
METHODS: 10 subjects with COPD were commenced on Seretide combination therapy for 3 months. At the baseline visit, subjects completed the St George Respiratory Questionnaire (SGRQ) and underwent spirometry, FOT measures of reactance (Xrs), resistance (Rrs) at 6 Hz, expiratory flow limitation defined as the difference between mean inspiratory and expiratory Xrs (Δ Xrs), DLCO, and plethysmography. All tests were repeated at the completion of 3 months of Seretide therapy.
RESULTS: Subjects were of mean (SD) age 68.1 years (8.0), BMI 29.6 (6.7), pack years 49 (20.3), post FEV1 % predicted 68.3(19.8).FEV1/FVC 60.0 % (9.28), TLC % predicted 109.9 (19.7), FRC % predicted 121.6 (32.7), RV/TLC 54.3 (7.5). Mean (SD) Reactance (Xrs) was -3.86 (2.37) cmH2O/l/sec, expiratory flow limitation Δ Xrs) 3.78 (2.8) cmH2O/(l/sec), Rrs 5.6 (1.08). After 3 months of Seretide therapy, there were improvements in SGRQ score (-11.19 p=0.002), despite no significant change in FEV1 (+90ml p 0.14). There were improvements in Xrs (+1.2 cmH2O/l/sec, p 0.02), Δ Xrs (-1.44 cmH2O/l/sec, p=0.02), and Rrs (-0.57 cmH2O/l/sec, p=0.002). Hyperinflation also improved: TLC -233ml (p=0.02), FRC -291ml (p=0.03), and RV -228ml (p=0.03). The change in reactance was significantly associated with change in FRC (r=0.66, p=0.04). The improvements in SGRQ were not associated with changes in any of the lung function parameters.
CONCLUSIONS: Combination therapy is associated with improvements in small airways function and hyperinflation in COPD, despite an absence of change in FEV1.
CLINICAL IMPLICATIONS: FOT may be a clinically useful marker of small airway function in COPD that is responsive to treatment
DISCLOSURE: Sophie Timmins: Grant monies (from industry related sources): Boehringer Ingelheim & Pfizer Travel Grant to attend the ACCP, Grant monies (from sources other than industry): Cooperative Research Centre for Airways and Asthma PHD Top-Up Scholarship, Grant monies (from sources other than industry): Australian Lung Foundation PHD Scholarship
Norbert Berend: Consultant fee, speaker bureau, advisory committee, etc.: Norbert Berend serves on advisory boards for GSK, AstraZeneca, Boehringer Ingelheim, Pfizer and Nycomed , Other: Norbert Berend has accepted travel grants from GSK, AstraZeneca, Boehringer Ingelheim, Pfizer, Bayer and Nycomed., Grant monies (from sources other than industry): Norbert Berend is the Director of the Woolcock Institute of Medical Research which has conducted contract clinical trials with AstraZeneca, Biota, Boehringer Ingelheim, Cephalon, GSK, Covance, Novartis, Pfizer, Pharmaxis, Sanofi Aventis, Servier, Vanda. as well as conducting studies for the NSW State Government, Consultant fee, speaker bureau, advisory committee, etc.: The Woolcock has or has had consultancy agreements with GSK, AstraZeneca , Boehringer Ingelheim and Pfizer
Cheryl Salome: Grant monies (from industry related sources): Cheryl Salome has received research funding from Astra-Zeneca, Boehringer Ingelheim and GSK., Other: Cheryl Salome has received travel grants from Astra-Zeneca, Boehringer Ingelheim and GSK.
Gregory King: University grant monies: YES. PhD Students who I supervise receive scholarships. Yearly from 2007 onwards, $20K/scholarship., Grant monies (from industry related sources): YES. Yearly from 2008 onwards. Dr King’s research group received monies to support salaries and conduct research projects both directly from industry and as an allocation from unrestricted grants across all groups within the Institution, provided to The Woolcock Institute of Medical Research (Boehringer Ingelheim, Pfizer, Glaxo-Smith Kline, AstraZeneca, Pharmaxis). $200K/year for the Woolcock Institute as a whole., Grant monies (from sources other than industry): YES. Yearly from 2008 onwards. The Cooperative Research Centre for Asthma and Airways, National Health & Medical Research Council grants and scholarships, Foundation grants including local hospital and Asthma Foundations, Australian Lung Foundation and scholarships which are used for Dr King’s salary, research group salaries and project costs. $500K/year., Consultant fee, speaker bureau, advisory committee, etc.: Yes. Dr King is part of a Consultancy Agreement of The Woolcock Institute of Medical Research and Industry. An allocation of monies received for consultancy work is allocated to his research group. , Consultant fee, speaker bureau, advisory committee, etc.: Yes. From 2008 onwards. Dr King speaks at industry organized functions and meetings. (Boehringer Ingelheim, Pfizer, Glaxo-Smith Kline, AstraZeneca and Novartis). Honoraria are paid to The Woolcock Institute of Medical Research, from which his research group receives an allocation. $1000-2000/year., Other: YES. Yearly from 2008 onwards. Travel and accommodation costs paid for from industry sources (Boehringer Ingelheim, Pfizer, Glaxo-Smith Kline, AstraZeneca) The amount varies from $10-20K/year.
The following authors have nothing to disclose: Chantale Diba, Catherine Farrow
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