BackgroundIntra-breath oscillometry has been proposed as a sensitive means of detecting
airway obstruction in young children. We aimed to assess the impact of early life
wheezing and lower respiratory tract illness on lung function, using both standard
and intra-breath oscillometry in 3 year old children.MethodsHistory of doctor-diagnosed
asthma, wheezing, bronchiolitis and bronchitis and hospitalisation for respiratory
problems were assessed by questionnaires in 384 population-based children. Association
of respiratory history with standard and intra-breath oscillometry parameters, including
resistance at 7 Hz (R7), frequency-dependence of resistance (R7 - 19), reactance at
7 Hz (X7), area of the reactance curve (AX), end-inspiratory and end-expiratory R
(ReI, ReE) and X (XeI, XeE), and volume-dependence of resistance (Delta R = ReE-ReI)
was estimated by linear regression adjusted on confounders.ResultsAmong the 320 children
who accepted the oscillometry test, 281 (88%) performed 3 technically acceptable and
reproducible standard oscillometry measurements and 251 children also performed one
intra-breath oscillometry measurement. Asthma was associated with higher ReI, ReE,
Delta R and R7 and wheezing was associated with higher Delta R. Bronchiolitis was
associated with higher R7 and AX and lower XeI and bronchitis with higher ReI. No
statistically significant association was observed for hospitalisation.ConclusionsOur
findings confirm the good success rate of oscillometry in 3-year-old children and
indicate an association between a history of early-life wheezing and lower respiratory
tract illness and lower lung function as assessed by both standard and intra-breath
oscillometry. Our study supports the relevance of using intra-breath oscillometry
parameters as sensitive outcome measures in preschool children in epidemiological
cohorts.
