Long-term effects of bronchopulmonary dysplasia on lung function: a pilot study in preschool children's cohort

Introduction: Although the long term negative effects of bronchopulmonary dysplasia (BPD) are well known, follow-up studies of preterm infants with BPD into childhood are lacking.Methods: Forty-two preschool children (age range 3-6 years) who were born before 32 weeks of gestational age and affected by BPD were enrolled. Pre-, peri-, and post-natal data were collected. During the follow up appointment complete physical examination and lung function (impulse oscillometry (IOS)) were recorded. The European Community Respiratory Health Survey (ECRHS) questionnaire was administered to all enrolled subjects.Results: Thirty patients were included in the final analysis. The BPD group did not differ in comparison to the non-BPD group in terms of lung function (p > 0.05). By comparing all subjects enrolled, We detected extremely low-birth-weight (ELBW) infants with height-, weight-, and gender-related reference values and a significant trend of increasing resistance values (R5Hz, R5-20 Hz) and respiratory impedance (Z5Hz) (p < 0.05). No significant difference in bronchial reversibility test was observed among BPD non-BPD groups (p < 0.05). The frequency of gastroesophageal reflux disease was significantly higher in patients with BPD when compared to non-BPD group (p < 0.05). Significant differences in gestational age, oxygen supplementation (days), mechanical ventilation therapy (days), and sepsis between BPD and non-BPD groups were also observed (p < 0.05). There were no significant differences in the prevalence of family and personal history of atopy and/or allergic diseases, tobacco exposure, respiratory symptoms, respiratory syncytial virus bronchiolitis, exercise induced dyspnea, treatment with ß-2 bronchodilators and inhaled corticosteroids among the groups (p > 0.05).Conclusions: The respiratory function in preschool children born with ELBW is characterized by an increase in impedance and resistance of small airways. No statistically significant differences were found between ELBW children with BPD and without BPD. With regards to the smallest gestational age, the longer duration of O₂ therapy during hospitalization, and sepsis significantly resulted in a worse respiratory function.

Keywords: Bronchopulmonary dysplasia; impulse oscillometry; long-term outcomes; prematurity; preschool children.