494 Pulmonary Oxygen Uptake Capacity is Reduced in School-Aged Children After Bronchopulmonary Dysplasia (BPD)

Abstract

Background: Disturbed pulmonary vascularization and alveolar development are hallmarks of BPD in the era of surfactant therapy and antenatal steroids. Data on long-term functional consequences of these changes are scarce. The objective of our study was to assess aerobic fitness of formerly very low birth weight infants (VLBW) with and without BPD compared with children born at term and to identify factors accounting for group differences.Methods: Fourty children aged 7.9-12.9 years volunteered for this study. Ten children had BPD, 15 were VLBW without BPD (non-BPD) and 15 formerly term infants served as controls (CON). Aerobic fitness was assessed as peak oxygen uptake, allometrically adjusted for body mass (VO2peakadj), during an incremental cycling task to volitional fatigue. Physical activity (PA) was expressed as relative time in moderate-and-vigorous PA (MVPA).Results: The 3 groups did not differ in anthropometric indices. Although heart rate and respiratory exchange ratio at the end of exercise were identical among groups, VO2peakadj was lower in the BPD group (1329±149 ml/min) compared with non-BPD (1526±152 ml/min) and CON (1536±197 ml/min). MVPA was lower in VLBW (BPD 1.7±1.1%, non-BPD 2.2.±0.9%) compared with CON (4.4±1.1%). The difference in aerobic fitness was not explained by differences in PA. Several lung function parameters were decreased in BPD. Only adjustment for diffusion capacity abrogated the association of BPD with decreased aerobic fitness.Conclusions: The impaired diffusion capacity and aerobic fitness of school-aged children with BPD indicate a long-term functional consequence of disturbed pulmonary vascular and alveolar development in the disease.