SUMMARY/ABSTRACT
Introduction: Children with a history of bronchopulmonary
dysplasia (BPD) may have lower physical activity levels, but evidence to
date is based on self-report. This study compared physical activity
levels between children born extremely preterm with and without history
of BPD, and examined their associations with pulmonary magnetic
resonance imaging (MRI) and pulmonary function test (PFT) indices.
Methods: This multi-centre cross-sectional study included
children aged 7-9 years born extremely preterm, with and without BPD.
Children wore a pedometer for one week, then completed the Physical
Activity Questionnaire (PAQ), pulmonary MRI, and PFT. Spearman
correlations and multivariable linear regression modelling were
performed.
Results: Of 45 children, 28 had a history of moderate-severe
BPD. There were no differences in any physical activity outcomes by BPD
status. Higher average daily step count and higher average daily
moderate-vigorous physical activity (MVPA) were each correlated with
greater forced vital capacity (r=0.41 and 0.58), greater MRI lung proton
density at full expiration (r=0.42 and 0.49), and lower lung clearance
index (r=-0.50 and -0.41). After adjusting for MRI total proton density
and BPD status, a 5% increase in forced expiratory volume at one second
was associated with 738 (95%CI: 208, 1268) more steps per day and 0.1
(0.0, 0.2) more hours of MVPA, respectively.
Conclusion: School-aged children born extremely preterm have
similar physical activity levels to their peers, regardless of history
of BPD. MRI and PFT measures suggestive of gas trapping and/or airflow
obstruction are associated with lower physical activity levels.
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