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Lung function trajectories and determinants from birth to 6 years in an African birth cohort: extending trajectories
Diane M Gray1, Anhar Ullah2, Shaakira Chaya3
1Department of Paediatrics and Child Health, and SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa diane.gray@uct.ac.za.
Insights
Early childhood lung function trajectories impact lifelong health. Identifying specific patterns and risk factors like prematurity and RSV-LRTI can guide interventions for better lung development.
Area of Science:
- Pediatric respiratory health
- Developmental pediatrics
- Public health
Background:
- Childhood lung function trajectories are linked to lifelong health risks.
- Data on infant and preschool lung function development is limited.
- Early childhood is a critical period for lung growth and potential intervention.
Purpose of the Study:
- To investigate lung function trajectories from birth to age six.
- To identify determinants of these trajectories in an African birth cohort.
- To understand early life impacts on respiratory health.
Main Methods:
- Longitudinal intra-breath oscillometry measurements from six weeks to six years.
- Group-based multi-trajectory modeling of respiratory system impedance (Ree, Xee).
- Comprehensive collection of antenatal and childhood exposure data.
Main Results:
- Five distinct lung function trajectories identified: Normal, Persistent low, Early normal-declines, Early low-catch up, and Decline and recovery.
- 11% of children exhibited persistently low lung function, associated with RSV-LRTI, prematurity, and maternal distress.
- 19% showed catch-up to normal lung function by age six.
Conclusions:
- Early life lung function trajectories are crucial for healthy lung development and recovery.
- Factors like prematurity, RSV-LRTI, and maternal psychological distress negatively influence lung trajectories.
- Identifying specific trajectories can inform targeted interventions for improved pediatric respiratory health.
Background:
Impaired lung function trajectories in childhood are associated with lifelong health risk. However, data are lacking on trajectories in infancy and preschool years, a time of critical lung growth with potential for interventions. We investigated lung function trajectories from birth through 6 years, and their determinants, in the Drakenstein Child Health study, an African birth cohort.
Methods:
Children were followed from birth, with lung function (intra-breath oscillometry) measured at six time points (6 weeks to 6 years). Comprehensive exposure information was longitudinally collected from the antenatal period through childhood. Longitudinal data on end-expiratory resistance and end-expiratory reactance were jointly modelled using group-based multi-trajectory modelling to derive trajectories of respiratory system impedance.
Results:
830 children with two or more lung function measures were included. A model comprising five trajectories was the optimal solution: normal (70.2%); persistent low (2.4%); early normal-decline (8.4%); early low-catch-up (5.8%); and decline and recovery (13.1%). 90 children (11%) had low trajectories (persistent low or early normal-decline). Risk factors were respiratory syncytial virus-lower respiratory tract infection, preterm birth and postnatal maternal psychological distress. 157 children (19%) showed catch-up to normal lung function (early low-catch-up or decline and recovery) through 6 years. Spirometry at 6 years differed by trajectory: children in the normal trajectory had the highest forced expiratory volume in 1 s and forced vital capacity, and those in the persistent low trajectory had the lowest.
Conclusion:
Specific early-life lung function trajectories show potential for healthy lung development and recovery in early childhood. Modifiable factors including prematurity, respiratory syncytial virus-lower respiratory tract infection and maternal psychological distress negatively affect lung trajectories.
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