Lung function in school children born early. Identifying those at future risk.

This thesis has used community lung function testing in children aged 7 to 12 years to identify and understand persisting lung function deficits in those born preterm (≤34 weeks’ gestation) compared with those born at term (≥37 weeks’ gestation). I have evaluatedspirometry measures, reversibility testing and FeNO measurements. With data from 739 children, 544 preterm- and 195 term-born, it is one of the largest studies of its kind. I have described how preterm-born children continue to have significant lung function deficits. They also have greater response to 400mcg inhaled salbutamol compared with term-born controls. However, there were no differences in FeNO measurements. I evaluated the impact that CLD has on childhood lung function and discovered that pretermborn children with and without CLD have significant lung function deficits. Furthermore, exploratory analysis of early life factors identified that IUGR and gestation are significantly associated with childhood lung function deficits, but CLD is not. Evaluation of children by current %FEV1 revealed that a significant proportion of children with lung function deficits were not receiving any treatment despite having evidence of a positive bronchodilator response. Using a combination of current %FEV1 and FEV1/FVC I have identified two different respiratory phenotypes: obstructive and non-obstructive. I found that children with the obstructive phenotype have greater lung function deficits, respiratory symptoms, diagnosis of asthma and inhaler use. They also had a greater response to 400mcg salbutamol and a higher proportion of children with a FeNO >35ppb. I have successfully demonstrated that community lung function testing can assist in identifying children with ongoing lung function deficits and identify those more likely to benefit from inhaled treatments. I propose ongoing community-based surveillance in this vulnerable group of children to improve identification of ongoing lung function deficits and assist in optimising respiratory health