PURPOSE OF THE STUDY.
Children with asthma have reduced lung function. This study addresses the question: Are they born that way?
Prospective birth cohort of 411 children from Denmark whose mothers had a physician’s diagnosis of asthma.
At age 1 month, subjects’ spirometric and bronchial responsiveness to methacholine was obtained by thoracic compression technique. At age 7 years, subjects’ lung function was measured by using spirometry. Asthma was diagnosed prospectively, from daily diary cards and clinic visits every 6 months, if the following were noted: recurrent episodes of troublesome lung symptoms typical of asthma, need for rescue use of inhaled β2-agonist, and response to inhaled corticosteroids.
Children with asthma by age 7 years (14%) already had a significant airflow deficit as neonates (forced expiratory flow at 50% reduced by 0.34, z score, P = .03), which progressed (0.82 z score, P < .0001) by age 7 years, suggesting that ∼40% of the airflow deficit associated with asthma is present at birth, whereas 60% develops with clinical disease. Bronchial responsiveness to methacholine in neonates was associated with the development of asthma (P = .01).
Children developing asthma by 7 years of age had a lung function deficit and increased bronchial responsiveness as neonates. This lung function deficit progressed to age 7 years.
Our interventions to try to prevent or to treat asthma may have to begin even before birth because it seems that children who go on to have asthma are born with decreased lung function. Furthermore, we will need more effective treatments because the loss of lung function progressed throughout childhood despite treatment with inhaled corticosteroids.
- Copyright © 2013 by the American Academy of Pediatrics