Determinants of baseline lung function and bronchodilator response in 4-year-old children

Abstract

The prolonged period required for maturation of the respiratory system makes it vulnerable to environmental exposure. This study aimed to investigate the association between early-life factors and lung function in preschool children.Children aged 4 years, who were included in a prospective birth cohort, underwent lung function testing at baseline (n5535) and after bronchodilation (n5498) by forced oscillations. Information on symptoms and exposures was collected through half-yearly questionnaires. Allergen-specific serum IgE was quantified at 1 and 4 years.Multiple linear regression analysis showed that the baseline respiratory resistance and reactance area were larger in the children with previous wheeze, those with early-onset sensitisation to inhalant allergens and those who were smaller. Furthermore, children with previous lower respiratory tract infections exhibited higher baseline resistance values. The baseline resistance was the only independent determinant of the bronchodilator-induced change in resistance, whereas current height and baseline reactance area were independently associated with the change in reactance area.In conclusion, previous lower respiratory tract infections, the timing of previous wheeze, inhalant sensitisation and current height independently influence the baseline lung function of 4-year-old children, whereas baseline lung function is the principal determinant of the bronchodilator response. @ERSpublications Height, LRTIs, wheeze and sensitisation to inhalant allergens are determinants of lung function in preschool children

Bronchodilator response in wheezing infants assessed by the raised volume rapid thoracic compression technique

“…Infants from the WG had worse lung function when compared to the CG, as expected. The reduction in lung function seems to be associated with the number of episodes of wheezing and lower respiratory tract infections [14]. Almost half of the patients evaluated in the WG reported previous hospitalization.…”

Lung function testing and inflammation markers for wheezing preschool children: A systematic review for the EAACI Clinical Practice Recommendations on Diagnostics of Preschool Wheeze

“…4,36,37 According to these studies, height was found to be the most influential variable on respiratory system resistance (Rrs) and reactance (Xrs), the components of respiratory impedance (Zrs) ( Table 1) The studies evaluating the oscillometric technique's ability to classify lung function in wheezing and healthy children have been contradictory. Depending on the patient selection, both significant differences [40][41][42][43] and lack of differences 12,44 have been reported.…”

“…The studies evaluating the oscillometric technique's ability to classify lung function in wheezing and healthy children have been contradictory. Depending on the patient selection, both significant differences 40–43 and lack of differences 12,44 have been reported. Apparent changes in resistance at low frequencies (Rrs at 5 Hz) may suggest small airway involvement and predict loss of asthma control 45,46 …”

“…38 The studies evaluating the oscillometric technique's ability to classify lung function in wheezing and healthy children have been contradictory. Depending on the patient selection, both significant differences [40][41][42][43] and lack of differences 12,44 have been reported.…”

Systems physiology of the airways in health and obstructive pulmonary disease

“…Also, they cannot be measured in individuals unable to perform forced expiratory maneuvers on command, such as very young children and some infirmed adults. For these reasons, the measurement of impedance with the forced oscillation technique has been gaining increasing acceptance as a clinical means of assessing lung function 39,50,51 ; impedance can be measured without the need for specialized breathing maneuvers, and it can be related, in principle, to lung structure on the basis of physiologically meaningful mathematical models of the lung. 4,39 V T = 800 ml V T = 700 ml Long-term treatment with inhaled corticosteroids can bring baseline lung function back into the normal range in many asthmatic individuals.…”