Keywords:
Bronchopulmonary dysplasia; exercise; lung function; preterm birth; wheeze
Abstract:
OBJECTIVE: To determine the relationships between respiratory symptoms, lung function, and neonatal events in young preterm children.
METHODS: Preterm children (<32 w gestation), classified as bronchopulmonary dysplasia (BPD) or non-BPD, and healthy term controls were studied. Lung function was measured by forced oscillation technique (respiratory resistance [Rrs] and reactance [Xrs]) and spirometry. Respiratory symptom questionnaires were administered.
RESULTS: One hundred and fifty children (74 BPD, 44 non-BPD, 32 controls) 4-8 years were studied. Lung function (median Z-score [10,90th centile]) was significantly impaired in preterm children compared to controls for FVC (0.00 [-1.18, 1.76], 0.69 [-0.17,1.86]), FEV1 (-0.44 [-1.94, 1.11], 0.49 [-0.83, 2.51]), Xrs (-1.26 [-3.31, 0.11], -0.11 [-0.97, 0.73]), and Rrs (0.55 [-0.48, 1.82], 0.28 [-0.99, 0.96]). Only Xrs differed between the BPD and non-BPD (-1.51 [-3.59, -0.41], -0.89 [-2.64, 0.52]). The prevalence of recent respiratory symptoms (range: 32-36%) did not differ between BPD and non-BPD children. Supplemental O2 in hospital was positively associated with worsening Xrs and FEV1 .
CONCLUSION: Preterm children have worse lung function than healthy controls. Only respiratory reactance differentiated between preterm children with and without BPD and was influenced by days of O2 in hospital.