Abstract
Preterm birth, low birth weight and high infant weight gain are associated with increased risks of childhood asthma. An important underlying pathway might be smaller airways and subsequent lower lung function. We examined the association of early growth characteristics with the risk of lower lung function, using data from 24,715 children of 24 European birth cohorts.
Studies were eligible if they included children from 1989 onwards, had information on gestational age, birth weight or infant weight gain, and lung function (FEV1, FVC, FEF25-75, FEF75) at age 4-18 years. Random-effect meta-analyses were used with individual participant data and pooled effect estimates.
Younger gestational age and lower birth weight were associated with lower lung function values (p-values < 0.05). We observed the strongest independent effects for preterm birth (<37 vs. ≥37 weeks) on FEV1/FVC and FEF75 (-0.15 (-0.22, -0.09) and -0.14 (-0.22, -0.07) pooled Z-scores), and for low birth weight (<2500 vs. ≥2500 grams) on FEV1, FVC and FEF25-75 (-0.26 (-0.33, -0.19), -0.20 (-0.28, -0.12), and -0.20 (-0.28, -0.12) pooled Z-scores). Higher infant weight gain, independent of birth characteristics, was associated with higher FVC, and lower FEV1/FVC ratio, FEF25-75 and FEF75 Z-scores (p-values < 0.05). These associations were not explained by respiratory tract infections, allergy, eczema, asthma, or use of asthma medication.
Younger gestational age, lower weight at birth and higher infant weight gain are associated with lower lung function in childhood. Smaller airways might be partly responsible for associations of early growth characteristics with asthma.
- © 2014 ERS
