Effect of Inhaled Steroids on Lung Function in Young Children: A Cohort Study

Abstract

Devulapalli CS, Haaland G, Pettersen M, Carlsen KH, Lodrup Carlsen KC. Eur Respir J. 2004;23:869–875To determine the use of inhaled corticosteroids (ICSs) for treating recurrent bronchial obstruction in young children up to 2 years of age and to assess possible modifying effects of ICSs on lung function in young children with recurrent bronchial obstruction.Observational, noninterventional birth cohort of 3754 newborn children (3697 with complete questionnaire data by 2 years of age); 306 children with documented recurrent bronchial obstruction by 2 years old were identified along with 306 matched controls.Two tidal-flow/volume measurements were taken (1 at presentation of disease [children were steroid naive] and 1 at 2 years of age [mean ages: 11.2 and 25.6 months, respectively]) from 21 subjects who subsequently received ICS (ICS+), 33 who did not receive ICS (ICS−), and 15 controls. The mean ± SD duration of ICS treatment was 10.3 ± 6.5 months. The main outcomes were treatment with ICS and baseline ratio of time to peak expiratory flow otal expiratory time (tPTEF/tE).From the entire cohort, 77 children (2.1%) and 64 of 306 children (21%) with recurrent bronchial obstruction had received ICS by 2 years of age. Baseline tPTEF/tE was significantly lower at the first visit in ICS+ subjects, as compared with ICS− subjects, as well as in ICS+ and ICS− subjects as compared with controls. The mean difference in baseline tPTEF/tE from the first to second visit was borderline statistically significant in the ICS+ group only and correlated significantly with the duration of ICS treatment.The present observational cohort study demonstrated that one fifth of young children with recurrent bronchial obstruction had received ICSs. Early ICS treatment improved lung function by the age of 2 years, mostly in those with the longest duration of treatment.There is little information available concerning how often inhaled steroids are used during the first 2 years of life in the treatment of obstructive airway disease and limited information on the modifying effects of ICSs on the development of lung function in early life. As expected, infants with recurrent bronchial obstruction and lower lung function were treated more often with ICS compared with matched controls. Improvement in lung function in these children increased with increasing duration of treatment. This study suggests that the choice of medical therapy is often determined by the clinical state of the child, and once started, it may be a factor that can influence later outcome. More studies such as this are desirable to fully understand the role of ICSs in early life.