Researchers in Australia measured forced vital capacity and forced expiratory flows at 75% of exhaled vital capacity on 68 babies with cystic fibrosis and 49 without, aged between six weeks and 30 months.
The infants were assessed 48 hours later for pulmonary infection and inflammation.
Results showed scores did not differ between babies with cystic fibrosis and health controls less than six months of age.
However forced vital capacity score was lower by 1.15 in infants with CF who were older than six months compared with healthy infants.
Authors wrote: ‘Lung function, measured by forced expiration, is normal in infants with CF at the time of diagnosis by newborn screening but is diminished in older infants.
'These findings suggest that in CF the optimal timing of therapeutic interventions aimed at preserving lung function may be within the first 6 months of life.’
American Journal of Respiratory and Critical Care Medicine (2008) 178:1238-1244