Altered breathing mechanics and ventilatory response during exercise in children born extremely preterm

Area of Science:

• Pediatric Pulmonology
• Neonatal Intensive Care
• Exercise Physiology

Background:

• Extreme preterm birth (EP) is linked to long-term lung function and exercise capacity deficits.
• Factors contributing to exercise limitation in EP survivors are not well understood.
• This study investigates respiratory mechanics and ventilatory responses during exercise in EP children.

Purpose of the Study:

• To examine respiratory mechanics and ventilatory response during exercise in children born extremely preterm (EP).
• To compare EP children with and without moderate/severe bronchopulmonary dysplasia (BPD) to controls.

Main Methods:

• A cohort study of children aged 8-12 years born EP (≤28 weeks gestation).
• EP children categorized into no/mild BPD (n=53) and moderate/severe BPD (n=50) groups.
• Age-matched full-term control children (n=65) included for comparison.
• Lung function and cardiopulmonary exercise testing were performed on all participants.

Main Results:

• EP children exhibited lower airway flows and diffusion capacity than controls, with preserved total lung capacity.
• Moderate/severe BPD group showed gas trapping and significantly reduced exercise capacity (VO2 % predicted).
• Moderate/severe BPD group displayed potentiated ventilatory response and higher prevalence of expiratory flow limitation during exercise.

Conclusions:

• Expiratory flow limitation and exaggerated ventilatory response are key factors limiting exercise in EP children with moderate/severe BPD.
• These findings highlight specific physiological challenges affecting exercise capacity in this vulnerable population.