A Danish [removed]study[/removed] finds that children who develop asthma by age 7 have deficits in lung function and increased bronchial responsiveness as neonates. The findings appear in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
While previous research on the relationship between neonatal lung function and the development of asthma has been “conflicting,” according to the researchers, this study shows that children with asthma by age 7 “already had significant airflow deficits and increased bronchial responsiveness as neonates.” In addition, they found that lung function deficits also progressed throughout childhood, “suggesting a potential opportunity for early intervention.”
The prospective study enrolled a birth cohort of 411 at-risk children of asthmatic mothers. Spirometry was performed at 1 month in 403 (98%) children and again at age 7 in 317 (77%).
Significant neonatal airflow deficits, as measured by forced expiratory flow at 50% of vital capacity and forced expiratory volume after 0.5 seconds, were observed among the 14% of children who developed asthma by age 7. Bronchial responsiveness to methacholine, which provokes narrowing of the airways, was also significantly associated with the development of asthma. Neonatal airway reactivity was a stronger predictor of asthma than neonatal lung function.
“We found that approximately 40% of the airflow deficit that was associated with asthma in our study was present at birth, while 60% developed through early childhood along with the disease,” said Hans Bisgaard, MD, DMSci, professor of pediatrics at the University of Copenhagen and head of the Danish Pediatric Asthma Centre. “This indicates that both prenatal and early childhood mechanisms are potential intervention targets for the prevention of asthma.”
The researchers caution that the study used a homogenous study sample, which might limit extrapolation of the results to other populations.
“It seems that lung function changes associated with asthma occur very early in life and maybe even before birth,” said Bisgaard. “This may explain the lack of effect from early intervention with inhaled corticosteroids and should direct research into the pathogenesis and prevention of asthma towards the earliest phases of life.”
Source: American Thoracic Society