Childhood asthma and reduced lung function : What comes first?

Abstract

The associations between early life lung function and obstructive airway disease and lung function development through childhood are still unsettled. The main aim of the thesis was to determine the overall association between lung function and asthma through childhood and it is based upon data from the prospective birth cohort study “the Environment and Childhood Asthma Study” including lung function measurement at birth and follow up until 10 years of age. <br> Children with reduced lung function at birth measured by tidal flow volume loops or passive respiratory mechanics had a doubling risk of asthma at ten years of age. Children who had reduced lung function measured by both methods represented a high risk group with a four doubling risk of asthma. Among the 10 years old children a lifetime prevalence of asthma of 20% and current asthma in 11% was found. Lung function through childhood was highly associated with lung function at birth and found to be independent of atopic disease and lower respiratory tract infections the first two years of life. In contrast to the previous belief that it is the first two years of life that are the most vulnerable in the development of the lungs, the results of the thesis point to pre natal factors as decisive for later obstructive airway disease and lung function development.