Perception of airway narrowing during reduction of inhaled corticosteroids and asthma exacerbation

• Published in: Thorax Vol. 58; no. 12; pp. 1042 - 1047
• Main Authors: Salome, C M, Leuppi, J D, Freed, R, Marks, G B
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Thoracic Society 01.12.2003; BMJ; BMJ Publishing Group Ltd; BMJ Publishing Group LTD; BMJ Group
• Subjects: Administration, Inhalation; Adrenal Cortex Hormones - administration & dosage; Adult; Airway management; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Asthma; Asthma - drug therapy; Asthma - physiopathology; Biological and medical sciences; Bronchi - drug effects; Bronchial Hyperreactivity - physiopathology; Bronchial Provocation Tests; Bronchitis - etiology; Bronchitis - physiopathology; Cardiology. Vascular system; Chronic obstructive pulmonary disease, asthma; corticosteroid dose; Dyspnea - etiology; Dyspnea - psychology; Female; Forced Expiratory Volume - drug effects; Humans; Inflammation; Male; Medical sciences; Middle Aged; Nitric Oxide - analysis; Perception; perception of airway narrowing; Pneumology; Sputum - cytology; Steroids; United Kingdom > UK; Lung disease; Corticosteroid; Respiratory disease; Narrowing; Asthma; Inhalation; Reduction; Bronchus disease; Anesthesia; Perception; Obstructive pulmonary disease; Circulatory system; Cardiology
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thorax.58.12.1042

Background: The perception of airway narrowing is reduced in subjects with severe asthma and may be related to the severity of airway inflammation. A study was undertaken to determine if the perception of airway narrowing changes during the reduction of inhaled corticosteroid (ICS) dose or during an asthma exacerbation. Methods: Forty two asthmatic subjects with well controlled asthma had their daily ICS dose halved every 2 months until they were weaned off ICS or they developed an exacerbation. Perception was measured at baseline and at monthly intervals during bronchial challenge with mannitol as the slope and intercept of the regression of the Borg score and percentage fall in forced expiratory volume in 1 second (FEV1), and as the Borg score at 20% fall in FEV1 (PS20FEV1). Sputum was collected for measurement of inflammatory cell numbers. Results: In 33 subjects who successfully halved their ICS dose without exacerbation there were significant reductions in slope (p = 0.01), intercept (p = 0.01), and PS20FEV1 (p = 0.003). Sputum eosinophils and airway hyperresponsiveness increased significantly but, in 14 subjects from whom sputum was obtained, changes in eosinophils were not correlated with changes in perception. Change in airway hyperresponsiveness correlated with change in PS20FEV1 (r = −0.40, p = 0.025). In 27 subjects who developed an exacerbation, slope decreased (p = 0.02) and intercept increased (p = 0.01) compared with the visit before the exacerbation. Changes in intercept correlated with changes in resting FEV1 (r = −0.57, p = 0.002). Conclusions: Perception of airway narrowing decreases during ICS dose reduction and decreases further during a mild asthma exacerbation. These changes are related to concurrent changes in airway hyperresponsiveness and resting lung function. The effect of changes in airway inflammation on perception is unclear.