BACKGROUND: It is unclear in which periods of life lung function deficits develop, and if these are affected by risk factors such as asthma, bronchial hyperresponsiveness (BHR) and allergic comorbidity. The goal of this systematic review is to identify temporal associations of asthma, BHR and allergic comorbidity with large and small lung function development from birth until peak function in early adulthood.
METHODS: We searched Medline, EMBASE, Web of Science and CINHAHL for papers published before 01.01.2020 on risk factors and lung function measurements of large and small airways. Studies were required to report lung function at any timepoint or interval from birth until peak lung function (age 21-26) and include at least one candidate risk factor.
RESULTS: Of the 45 papers identified, 44 investigated cohorts and one was a clinical trial with follow-up. Asthma, wheezing, BHR and allergic sensitization early in life and to multiple allergens were associated with a lower lung function growth of large and small airways during early childhood compared to the control populations. Lung function development after childhood in subjects with asthma or persistent wheeze, although continuing to grow at a lower level, largely tracked parallel to non-affected individuals until peak function was attained.
CLINICAL IMPLICATIONS AND FUTURE RESEARCH: Deficits in lung function growth develop in early childhood, and children with asthma, BHR and early life IgE (poly)-sensitization are at risk. This period is possibly a critical window of opportunity to identify at risk subjects and provide treatment aimed at preventing long-term sequalae of lung function.