Prenatal urban exposome and asthma up to adolescence ? a multicentre study (DataSHIELD)

Asthma and wheeze have been associated with several prenatal environmental exposures including tobacco smoke and traffic pollution (Gilliland et al, 2001; Hehua et al, 2017). Most studies conducted so far focused on single exposure or single family of exposure while individuals are continuously exposed to multiple factors in daily life. It is therefore relevant to consider in a single approach a large range of exposures, especially in the context of diseases with multifactorial etiology such as asthma.
Until now, studies investigating the role of environmental factors on asthma were mostly based on
population of children (Abellan et al., 2024; Guillien et al., 2023) or adults (Guillien et al., 2020 and 2022),
while the literature regarding population of adolescents, remains scarce. However, studying respiratory
health up-to adolescents is crucial because this period is a key developmental stage where respiratory
functions peak, ultimately influencing respiratory health in adulthood. Using longitudinal study over a long
period of time, events are not necessarily observed across the entire population, thus we have truncated (or
right-censored) data given the attrition over time. Most of previous studies have used logistic regression
model, although survival models, which are able to account for all data even if they are not “complete”, are
the model of choice when analyzing time-to-event data in long-term longitudinal cohort.
The objective is to study associations between the prenatal outdoor exposomes and the development of
asthma up to adolescence using the ATHLETE birth cohorts.

Outdoor exposome:
As we will investigate the age at which asthma developed, which could occur in early-childhood, we will focus
on the prenatal window of exposure (average during pregnancy). Sub-analyses on the different trimesters
can be performed to elucidate which trimester might be most important for disease development up to
adolescence.
Health outcomes:
– Asthma ever
– Asthma last 12 months
– Wheezing ever
– Wheezing last 12 months
Covariates:
Covariates to be included in the final statistical models will be decided by using a directed acyclic graph (DAG) approach.