Exercise capacity after extremely preterm birth. Development from adolescence to adulthood.

RATIONALE

Extremely preterm (EP) birth is associated with a series of adverse health outcomes, some of which may be alleviated by improved physical fitness. However, EP-born subjects are reportedly less physically active than term-born peers. Exercise capacity is poorly described in this group, and longitudinal data are needed.

OBJECTIVES

To compare exercise capacity of adults born EP and at term, and to address developmental patterns from adolescence to adulthood.

METHODS

An area-based cohort of adults, born in 1982-1985 at gestational age 28 weeks or earlier, or with birth weight of 1,000 g or less, originally examined at 18 years of age, were re-examined at 25 years of age together with individually matched term-born control subjects, using an identical maximal cardiopulmonary treadmill exercise test and validated questionnaires.

MEASUREMENTS AND MAIN RESULTS

A total of 34 (76%) eligible preterm and 33 (85%) term control subjects successfully completed the exercise test at age 25 years. In the two groups, average (95% confidence interval) peak oxygen consumption was 40.7 (37.9-43.5) and 44.2 (41.0-47.4) ml ⋅ kg(-1)⋅min(-1), respectively, whereas the distance completed on the treadmill was 910 (827-993) m and 1,020 (927-1,113) m. Peak oxygen consumption was unrelated to neonatal factors and current FEV1, but was positively associated with leisure-time physical activity and negatively associated with age at examination. Values obtained at age 18 and 25 years were strongly correlated and within normal range at both examinations.

CONCLUSIONS

Exercise capacity was modestly reduced in EP-born adults; however, values were within a normal range, positively associated with self-reported physical activity and unrelated to neonatal factors and current airway obstruction.