Reduced Exercise Capacity in Children Born Very Preterm

Abstract

OBJECTIVE. In the past 20 years, there has been an increase in survivors of very preterm birth, but little is known regarding their long-term respiratory and fitness outcomes. We aimed to assess the 10-year lung function and fitness outcomes for children who were born weighing <1000 g and before 32 weeks' gestation in 1992–1994. METHODS. A cross-sectional study was conducted of 126 children (mean age: 10 years) who were born at a mean gestation of 27 weeks and 34 term-born control subjects. Extensive lung function (spirometry, lung volumes, and gas exchange) and fitness (6-minute walk and 20-m shuttle run tests) assessments were conducted at a single visit according to previously validated techniques. RESULTS. The preterm group had significantly lower values for all measured spirometric parameters compared with the control group. In contrast to airflow, the preterm group had significantly higher percentage predicted values in all standard lung-volume parameters and transfer factor than the control group. The exercise capacity of the preterm group was approximately half that of the control group. There was no significant difference in the distance walked in the 6-minute walk test. CONCLUSIONS. In the largest cohort of school-aged children (born very preterm in the 1990s) to undergo extensive lung function and fitness assessments, we demonstrated significant impairment in exercise capacity despite evidence of only mild small-airway obstruction and gas trapping. Additional studies are required to evaluate the cause of this exercise limitation and whether it can be improved with a training program.