Air trapping in mild and moderate asthma: Effect of inhaled corticosteroids

doi:10.1016/j.jaci.2006.11.005

Journal of Allergy and Clinical Immunology

Volume 119, Issue 3, March 2007, Pages 583-590

https://doi.org/10.1016/j.jaci.2006.11.005 Get rights and content

Background

Air trapping reflects small airway obstruction in asthma and can be assessed quantitatively by high-resolution computed tomography (HRCT). Hydrofluoroalkane-beclomethasone dipropionate (HFA-BDP) is deposited across all sizes of airways, including the small ones. However, its long-term effect on air trapping remains unknown in uncontrolled asthma.

Objectives

To compare the effect of inhaled corticosteroids of different particle size—HFA-BDP and fluticasone propionate (FP)—on lung attenuation in mild-to-moderate uncontrolled asthma.

Methods

A randomized study was performed to analyze the effect of HFA-BDP (400 μg/d) or FP (500 μg/d) given over a period of 3 months to patients with uncontrolled mild-to-moderate asthma. HRCT was performed with spirometric gating, and lung attenuation was measured at residual volume and at pulmonary total capacity. The difference between inspiratory and expiratory attenuation was calculated as an air trapping index.

Results

Twenty-five out of 58 patients had abnormal air trapping and could be included in the study. Lung attenuation significantly diminished in the posterior zones of the lung after a 3-month treatment with HFA-BDP or FP, but the difference between the groups was not significant. Adjusted mean variations of the air trapping index from baseline to treatment completion were 34.3 (11.2, 57.3) and 27.3 (6.4, 48.2) for the HFA-BDP and FP groups, respectively. However, the reduction of air trapping area was more pronounced in the group treated with HFA-BDP.

Conclusion

Inhaled corticosteroids decrease air trapping in uncontrolled asthma regardless of their particle size.

Clinical implications

In mild-to-moderate asthma, air trapping assessed by HRCT may be a new outcome related to the control of the disease.

Section snippets

Patients

We consecutively enrolled 58 patients with mild or moderate asthma according to Global Initiative for Asthma guidelines.¹⁷ Selection criteria at screening visit included asthma diagnosis according to the American Thoracic Society (ie, either demonstration of airflow impairment reversibility of more than 12% after 400 μg salbutamol or, when FEV₁ was more than 70% of predicted value, demonstration of hyperresponsiveness after a methacholine challenge); uncontrolled asthma defined as, during the

Results

Thirty-three patients were randomized out of the 58 patients screened for the study (Fig 1). Among the nonrandomized patients, 20 had no AT, 3 withdrew consent during the study, and 1 required ear, nose, and throat surgery during the protocol. Six of the 33 randomized patients were excluded from the full analysis set because they did not perform the final visit. Two patients were excluded from the per protocol population because of major deviation: one had a treatment compliance of 3%, and the

Discussion

In the current study, we provide evidence that a prolonged treatment with ICS decreases AT in patients with mild-to-moderate uncontrolled asthma. Our results also show that an ATi based on the measurement of LA difference between inspiration and expiration by HRCT is significantly improved independently of any change in clinical or functional outcomes. The comparison of HFA-BDP with FP showed a similar effect in terms of LA, suggesting that factors other than the particle size must be taken

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: Disclosure of potential conflict of interest: A. Basset-Merle is employed by Synarc. P. Chanez is on the advisory board for 3M France and GlaxoSmithKline. The rest of the authors have declared that they have no conflict of interest.

View full text

Asthma diagnosis and treatmentAir trapping in mild and moderate asthma: Effect of inhaled corticosteroids

Background

Objectives

Methods

Results

Conclusion

Clinical implications

Section snippets

Patients

Results

Discussion

J Allergy Clin Immunol

J Allergy Clin Immunol

Chest

J Allergy Clin Immunol

Clin Radiol

J Allergy Clin Immunol

Site of airway obstruction in pulmonary disease: direct measurement of intrabronchial pressure

J Appl Physiol

The distal airways: are they important in asthma?

Eur Respir J

The structure of large and small airways in nonfatal and fatal asthma

Am Rev Respir Dis

Lymphocyte and eosinophil influx into alveolar tissue in nocturnal asthma

Am J Respir Crit Care Med

Transbronchial biopsy as a tool to evaluate small airways in asthma

Eur Respir J

Obliterative bronchiolitis: individual CT signs of small airways disease and functional correlation

Radiology

Computed tomography of the lungs in asthma: influence of disease severity and etiology

Am J Respir Crit Care Med

Uncomplicated asthma in adults: comparison of CT appearance of the lungs in asthmatic and healthy subjects

Radiology

Abnormalities of the airways and lung parenchyma in asthmatics: CT observations in 50 patients and inter- and intraobserver variability

Eur Radiol

Functional significance of air trapping detected in moderate asthma

Eur Radiol

Airway hyperreactivity: assessment with helical thin-section CT

Radiology

Comparative effects of hydrofluoroalkane and chlorofluorocarbon beclomethasone dipropionate inhalation on small airways: assessment with functional helical thin-section computed tomography

J Allergy Clin Immunol

Montelukast improves regional air-trapping due to small airways obstruction in asthma

Eur Respir J

Glossary of terms for CT of the lungs: recommendations of the Nomenclature Committee of the Fleischner Society

Radiology

Asthma diagnosis and treatment
Air trapping in mild and moderate asthma: Effect of inhaled corticosteroids