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.