Open AccessGestational Age and Cardiorespiratory Fitness in Individuals Born At Term: A Life Course Study
Author(s) -
Ferreira Isabel,
Gbatu Pei T.,
Boreham Colin A.
Publication year - 2017
Publication title -
journal of the american heart association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.494
H-Index - 85
ISSN - 2047-9980
DOI - 10.1161/jaha.117.006467
Subject(s) - medicine , cardiorespiratory fitness , confidence interval , gestational age , confounding , young adult , longitudinal study , pediatrics , gestation , incidence (geometry) , demography , pregnancy , genetics , physics , pathology , sociology , optics , biology
Background In contrast to the effects of preterm birth, the extent to which shorter gestational age affects the cardiorespiratory fitness ( CRF ) levels of individuals who were born at term (ie, between 37 and 42 weeks) is largely unknown. The aim of this study was to examine whether life‐course CRF levels varied across different gestational ages within the at‐term range. Methods and Results The association between gestational age (in weeks) obtained from Child Health Services records and CRF , estimated from field and laboratory tests and expressed by maximal oxygen uptake level through adolescence to young adulthood, was examined in 791 participants in the Northern Ireland Young Hearts Study, all singletons born at term. Longitudinal data were analyzed with generalized estimating equations, accounting for important potential confounders. Mean levels of CRF were 45.6, 43.7, and 33.0 mL/kg per minute when participants were aged 12, 15, and 22 years, respectively. After adjustment for confounders, each week increase in gestational age was associated with 0.46 mL/kg per minute (95% confidence interval , 0.14–0.79) in CRF . Compared with individuals born full term (39–40 weeks, n=533) or late term (41–42 weeks, n=148), those who were born early term (37–38 weeks, n=110) had a higher incidence of poor CRF (risk ratio, 1.57; 95% confidence interval , 1.14–2.16). The changes in CRF through adolescence to young adulthood were similar across groups, with those born early term consistently displaying the lowest CRF. Conclusions These findings suggest that early‐term births within the at‐term range are linked to poorer CRF through adolescence to young adulthood, and may have important clinical and public health implications for policies about (avoidable) early‐term deliveries given their recent increasing trends.