“Early growth characteristics and the risk of reduced lung function and asthma”
Younger gestational age, smaller size for gestational age and greater infant weight gain are associated with reduced childhood lung function. This reduced lung function partly explains the risk of childhood asthma.
These are the study conclusions of combined data from 24 European cohorts, including the Guipuzkoa, Menorca, Sabadell and Valencia INMA cohorts, which gathered results from almost 25000 children that were between 3.9 and 19.1 years old.
Children born preterm or with a low birth weight have more respiratory diseases during the first days of life. Furthermore, studies suggest that they also have an increased risk of respiratory diseases in adulthood. Recent studies suggest that preterm birth and small size of the baby for the gestational age could increase the risk of childhood asthma. However, the mechanisms which lead to this higher risk are not yet known. One explanation for the relationship between early growth and asthma relates to the development of the lungs and airways. These early growth characteristics would produce narrow airways, resulting in airway obstruction, which predisposes to asthma. A reduced airway calibre is reflected by lower lung function values. So far, studies focussing on birth weight and childhood lung function have reported inconsistent results.
The current study assessed this question for the first time. To this end, the relationship between preterm birth, smaller size for gestational age, and greater infant weight with lung function and childhood asthma was assessed. Then, it was explored whether the relationship of early growth characteristics with asthma was explained by lung function outcomes.
The results of this study imply that early growth characteristics might persistently affect lung function and thereby contribute to the risk of obstructive respiratory diseases later life. Further studies are needed to identify the developmental adaptations of the lungs and immune system that might explain the effect of lung function on the relationship between early growth characteristics and childhood asthma. Identification of avoidable exposures might lead to development of future preventive strategies against childhood asthma.
Reference: den Dekker HT, Sonnenschein-van der Voort AM, de Jongste JC, Anessi-Maesano I, Arshad SH, Barros H, Beardsmore CS, Bisgaard H, Phar SC, Craig L, Devereux G, van der Ent CK, Esplugues A, Fantini MP, Flexeder C, Frey U, Forastiere F, Gehring U, Gori D, van der Gugten AC, Henderson AJ, Heude B, Ibarluzea J, Inskip HM, Keil T, Kogevinas M, Kreiner-Møller E, Kuehni CE, Lau S, Mélen E, Mommers M, Morales E, Penders J, Pike KC, Porta D, Reiss IK, Roberts G, Schmidt A, Schultz ES, Schulz H, Sunyer J, Torrent M, Vassilaki M, Wijga AH, Zabaleta C, Jaddoe VW, Duijts L. Early growth characteristics and the risk of reduced lung function and asthma: A meta-analysis of 25,000 children. J Allergy Clin Immunol. 2016 Apr;137(4):1026-35.