Late Breaking Abstract - Lung function trajectories and determinants from birth to 6 years in an African birth cohort: Group-based multi-trajectory modelling

<bold>Background:</bold> Low or worsening lung function trajectories from childhood are associated with lifelong health risk. Data is lacking on trajectories in infancy and preschool years, a time of critical lung growth with potential for interventions. <bold>Aim:</bold> Describe lung function trajectories and determinants from birth through 6 years in the Drakenstein Child Health study, an African birth cohort. <bold>Methodology:</bold> Children were followed from birth, with lung function (intra-breath oscillometry) measured at 6 timepoints (6 wks to 6 yrs), comprehensive exposure information was collected from the antenatal period through childhood. Longitudinal resistance (Ree) and reactance (Xee) at end expiration were modelled using Group-based multi-trajectory modelling to describe joint trajectories of Ree and Xee. <bold>Results:</bold> 830 children with ≥ 2 measures were included. Five trajectories were described (Figure 1). 11% had low trajectories (persistent abnormal or deviating from average): risk factors were preterm birth or RSV-lower respiratory tract infection.19% showed catch-up to average (early abnormal-catch-up or transient deviation). <bold>Conclusion:</bold> Specific early life lung function trajectories show potential for recovery in early childhood. RSV-LRTI and preterm birth are important risk factors for persistently low or worsening trajectories. <bold>Funding:</bold> Bill & Melinda Gates Foundation, SA-MRC, UK-MRC, Wellcome Trust <fig><object-id>erj;64/suppl_68/PA3457/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>