Lung function and exercise capacity in prematurely born young people

Abstract

Objectives: To determine if lung function abnormalities in young people born very prematurely routinely exposed to antenatal corticosteroids and postnatal surfactant were associated with reduced exercise capacity.

Working hypothesis: In the current era, lung function abnormalities would not be associated with exercise intolerance STUDY DESIGN: Follow-up of young people from the United Kingdom Oscillation study (UKOS).

Patient-subject selection: One hundred twenty-six young people of 797 recruited to UKOS, born at a mean gestational age of 27 weeks were assessed at a mean age of 17 years.

Methodology: Forced expiratory flow at 75% of the expired vital capacity (FEF₇₅ ), forced expiratory volume in 1 second (FEV₁ ) and lung volumes (forced vital capacity [FVC]) and residual volume (RV) and functional residual capacity (FRC_pleth ) were assessed. Abnormal lung function was below the fifth centile and very abnormal lung function below the 2.5th centile. Exercise capacity was assessed using a modified shuttle sprint test and self-reported hours of exercise.

Results: Thirty-nine young people had an abnormal FEF₇₅ with an adjusted reduction in sprint distance of 114 m (P = .018) and an adjusted difference in self-reported exercise of 0.73 hours (P = .036). Twenty-seven young people had a very abnormal FEF₇₅ with an adjusted reduction in sprint distance of 159 m (P = .002) and adjusted reduction in self-reported exercise of 1.15 hours (P = .002).

Conclusion: Very prematurely born young people with abnormal airway function had a significant reduction in exercise capacity.

Keywords: antenatal corticosteroids; spirometry; surfactant.