The EPICure study: maximal exercise and physical activity in school children born extremely preterm.
BACKGROUND
Evidence regarding exercise capacity and physical activity in children born extremely preterm (EP) is limited. Since survivors remain at high risk for developing bronchopulmonary dysplasia (BPD) and long-term pulmonary sequelae, reductions in exercise capacity and activity levels may be present.


OBJECTIVE
To compare maximal exercise ventilation characteristics and physical activity levels at 11 years of age in children born EP (<25 completed weeks gestation) with those of full-term controls.


METHODS
Participants performed spirometry, body plethysmography and gas transfer testing. A peak exercise test was performed on a cycle ergometer. Physical activity was monitored by accelerometry for 7 days.


RESULTS
Lung function and exercise results were obtained in 38 EP children (71% prior BPD) and 38 controls. Those born EP had significantly lower Z-scores (mean (95% CI) of difference) for forced expiratory volume in 1 s (FEV(1); -1.74 (-2.25 to -1.23) and gas transfer (-0.73 (-1.31 to -0.17), and significantly greater Z-scores for residual volume (RV; 0.58 (0.10 to 1.10)) and RV/total lung capacity (TLC; 0.74 (0.29 to 1.19)). EP birth was associated with a significant reduction in peak oxygen consumption. EP children employed greater breathing frequencies and lower tidal volumes during peak exercise. No differences were observed in physical activity between groups.


CONCLUSIONS
The reduction in peak oxygen consumption in children born EP, and alterations in ventilatory adaptations during peak exercise were not explained by differences in physical activity, but probably reflects the long-term pathophysiological impact of EP birth.
Welsh
Liam
L
Portex Unit: Respiratory Medicine and Physiology, UCL, Institute of Child Health, London, UK.
Kirkby
Jane
J
Lum
Sooky
S
Odendaal
Dolf
D
Marlow
Neil
N
Derrick
Graham
G
Stocks
Janet
J
D000886:Anthropometry / Q000379:methods; D002648:Child; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D052577:Infant, Extremely Low Birth Weight / Q000502:physiology*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods; D015656:Respiratory Mechanics / Q000502:physiology