Belgrave DCM, et al. - Considering the significance of maximal lung function in early adulthood as a determinant of mortality and COPD, whether or not distinct trajectories of lung function are present during childhood and whether or not these extend to adulthood and infancy were investigated. Findings suggested that the risk of diminished lung function in early adulthood could be reduced via reducing childhood smoke exposure and minimizing the risk of early-life sensitisation and wheezing exacerbations.

Methods

• Two population-based birth cohorts (MAAS and ALSPAC) were studied with repeat spirometry from childhood into early adulthood (1046 participants from 5–16 years and 1390 participants from 8–24 years) to assess the trajectories of FEV₁.
• To investigate if these childhood trajectories extend from early life, a third cohort (PIAF) with repeat lung function measures in infancy (V'_maxFRC) and childhood (FEV₁; 196 participants from 1 month to 18 years of age) was used.
• Using latent profile modelling, trajectories were identified.
• An allele score was created to investigate genetic associations of trajectories, and a multivariable model was constructed to identify their early-life predictors.

Results

• Four childhood FEV₁ trajectories were identified: persistently high, normal, below average, and persistently low.
• Persistent wheezing and asthma were noted in association with the persistently low trajectory (129 [5%] of 2436 participants) throughout the follow-up.
• Genetic analysis revealed that the pooled relative risk ratio per allele was 0·96 (95% CI 0·92–1·01; p=0·13) for persistently high, 1·01 (0·99–1·02; p=0·49) for below average, and 1·05 (0·98–1·13; p=0·13) for persistently low compared with the normal trajectory.
• Researchers observed no progression of most children in the low V'_maxFRC trajectory in infancy to the low FEV₁ trajectory in childhood.
• Recurrent wheeze with severe wheezing exacerbations, early allergic sensitisation, and tobacco smoke exposure were noted to be the early-life factors associated with the persistently low trajectory.