ArticlesPoor airway function in early infancy and lung function by age 22 years: a non-selective longitudinal cohort study
Introduction
30 years ago, Burrows and coworkers made the seminal observation that adults with a history of paediatric respiratory illness had lower levels of lung function and were more likely to develop obstructive lung disease than those without such a history.1 One plausible interpretation of this finding is that respiratory infections can damage the lung and predispose to obstructive lung disease. However, events before any respiratory illness could also possibly predispose individuals both to these early illnesses and to subsequent chronic impairment of lung function.2 Our findings and those of others3, 4, 5, 6 supported this contention, by showing that children who presented with illnesses of the lower respiratory tract during their first years of life had lower maximal expiratory flows than others shortly after birth and before any such illnesses developed. These results suggest the hypothesis that chronic obstructive pulmonary disease has origins in fetal life, and specifically in the factors that determine intrauterine growth of lungs and airways.
Longitudinal studies have suggested that a substantial proportion of deficits in lung function that present during the third decade of life, and especially those in individuals who have a diagnosis of asthma, persist into late adulthood and predispose for the development of chronic obstructive pulmonary disease.7 We aimed to assess to what degree these deficits in lung function are already present in the early postneonatal period.
Section snippets
Participants
We enrolled 1246 healthy infants at birth, between 1980 and 1984, in the Tucson Children's Respiratory Study, a longitudinal non-selected cohort study.8 We developed a chest-compression technique, for assessment of pulmonary function in infancy, as the last 376 infants were enrolled in the study. Of these 376 eligible infants, 20 could not be contacted within the testing time, 111 did not have the consent of their parents, 27 had a lower respiratory infection, 35 did not fall asleep, seven were
Results
The 123 participants included in our study had more educated mothers (p=0·02) and more fathers with asthma (p=0·01) than the other 1123 children enrolled in the Children's Respiratory Study (table 1). Other than that, the baseline characteristics of the two groups did not differ.
Length-adjusted infant VmaxFRC did not seem to be associated with potential confounders such as birthweight or type of delivery, or parental ethnicity, asthma, smoking, age, or level of education (webtable 1). These
Discussion
We showed that up to 14% of the variance in measurements of airway function (FEV1, FEV1/FVC ratio, and FEF25–75) in young adults was related to the maximal flows at functional residual capacity (VmaxFRC), measured in the same individuals at 2 months. Infant lung function was correlated with all measurements of airway function at ages 11–22 years, but more strongly with measurements taken before bronchodilator use than with those after bronchodilation. Moreover, individuals who had low airway
References (45)
- et al.
Respiratory syncytial virus in early life and risk of wheeze and allergy by age 13 years
Lancet
(1999) - et al.
Flow limitation in infants with bronchopulmonary dysplasia and respiratory function at school age
Lancet
(2003) - et al.
Terminal bronchiolar duct ending number does not increase post-natally in normal infants
Early Hum Dev
(2000) Environmental factors and developmental outcomes in the lung
Pharmacol Ther
(2007)- et al.
Alternative projections of mortality and disability by cause 1990-2020: Global Burden of Disease Study
Lancet
(1997) - et al.
The relationship of childhood respiratory illness to adult obstructive airway disease
Am Rev Respir Dis
(1977) - et al.
The relationship between respiratory illness in childhood and chronic air-flow obstruction in adulthood
Am Rev Respir Dis
(1983) - et al.
Diminished lung function as a predisposing factor for wheezing respiratory illness in infants
N Engl J Med
(1988) - et al.
Asthma and wheezing in the first six years of life. The Group Health Medical Associates
N Engl J Med
(1995) - et al.
Lung function, pre- and post-natal smoke exposure, and wheezing in the first year of life
Am Rev Respir Dis
(1993)