Airway responsiveness: associated features in infants with recurrent respiratory symptoms

• Published in: The European respiratory journal Vol. 30; no. 6; pp. 1150 - 1157
• Main Authors: Kotaniemi-Syrjanen, A, Malmberg, L. P, Pelkonen, A. S, Malmstrom, K, Makela, M. J
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.12.2007; Maney
• Subjects: Biological and medical sciences; Bronchial Provocation Tests; Female; Humans; Infant; Lung - physiopathology; Male; Medical sciences; Methacholine Chloride; Pneumology; Recurrence; Respiration Disorders - complications; Respiration Disorders - prevention & control; Respiratory Hypersensitivity - complications; Human; Relapse; Hyperreactivity; bronchial provocation tests; Methacholine chloride; Bronchus; Infant; Recurrent; Respiratory system; Respiratory tract; Symptomatology; Association; Lung function; Airways hyperreactivity; pulmonary function tests; Pneumology; Provocation test
• DOI: 10.1183/09031936.00158106
• ISSN: 0903-1936

Increased airway responsiveness (AR) is one of the main pathophysiological manifestations of asthma. The present study aimed to define the clinical features associated with increased AR in infants with recurrent lower respiratory tract symptoms. AR was evaluated by performing a novel dosimetric methacholine challenge test. Increased AR to methacholine, defined as a methacholine dose of < or =0.90 mg producing a 40% fall (PD(40)) in the maximal flow at functional residual capacity (V'(max,FRC)), was associated with atopy (odds ratio (OR) 4.1; 95% confidence interval (CI) 1.3-13.3), a history of physician-confirmed wheezing with respiratory syncytial virus (OR 32.9; 95% CI 2.5-428.8) or of a nonspecified aetiology (OR 4.9; 95% CI 1.1-22.5), functional residual capacity z-score > or =2 (OR 36.8; 95% CI 2.9-472.6), and V'(max,FRC) z-score (OR 0.5; 95% CI 0.2-0.9) at baseline, when compared with infants with only mild or no responsiveness to methacholine (PD(40) V'(max,FRC) >0.90 mg). In conclusion, in recurrently symptomatic infants, increased airway responsiveness is associated with reduced baseline lung function, an atopic trait of the child, a history of physician-confirmed wheeze and viral aetiology of wheeze. Future intervention studies are needed to confirm the role of airway responsiveness in respiratory morbidity during infancy.