Respiratory health in prematurely born preschool children with and without bronchopulmonary dysplasia.

Objective To investigate the respiratory health of preterm infants with bronchopulmonary dysplasia (BPD) at preschool age and to determine whether lung function (measured by forced oscillation technique (FOT) and interruption technique (Rint) is affected by BPD in preterm infants compared with preterm infants without BPD. Study design Participants: 3 to 5 years of age born preterm with BPD (N = 40, mean gestational age 28 weeks, mean birth weight 1051 g), and without BPD (N = 36, mean gestational age 29 weeks, mean birth weight 1179 g). Outcome variables: prevalence of symptoms determined by European Community Respiratory Health Survey and lung function measured by FOT and Rint. Results A large percentage of infants in both preterm groups reported respiratory symptoms during the last 12 months. Lung function measurements showed higher resonant frequency (Hz) in BPD compared with non-BPD (mean 26.8 vs 22.7, P 4-24 (hPa.s/l)(–3.0 vs –1.9, P = .005). No differences were found in respiratory resistance between the groups, although the mean values of both groups were increased compared with reference values. Conclusion Preterm birth affects respiratory health at 3 to 5 years of age. Children with BPD could be distinguished from children without BPD based on a higher resonant frequency and a lower mean reactance.