Frequent episodes of bronchitis during childhood increase the risk of lung diseases such as asthma, pneumonia during adulthood, suggests a recent Australian study reported in BMJ Open Respiratory Research.¹

Researchers set out to explore the association between childhood bronchitis and respiratory outcomes i.e., pulmonary function and lung conditions, later on in life. For this, they recruited 3202 residents of Tasmania, who were born in 1961 and underwent their first check-up at 7 years of age, from the Tasmanian Longitudinal Health Study cohort. The participants were followed up for 46 years on average.

Out of the 3202 participants, mean age 53 years, included in the study, 47.5% were found to have experienced one or more episodes of bronchitis in childhood. They were further categorized as non-recurrent bronchitis (28.1%), recurrent non-protracted bronchitis (18.1%) and recurrent-protracted bronchitis (1.3%) based on severity with recurrent-protracted bronchitis being the most severe category. The prevalence of physician-diagnosed asthma, pneumonia and chronic bronchitis was higher at 53 years of age corresponding to the severity of bronchitis in childhood.

Compared to those with no history of childhood bronchitis, individuals in the recurrent-protracted bronchitis were most at risk. The likelihood of having current asthma at 53 years was nearly 5-folds higher with odds ratio of 4.54. This association with asthma was seen even in participants who did not have childhood asthma/wheezing at 7 years of age. This, the authors say, could be an outcome of the damage sustained by the airways due to frequent bronchitis episodes during childhood along with airway narrowing as a result of remodeling, which hampers normal development of airways.

Similarly, the probability of pneumonia diagnosis was also increased with  OR of 2.18. However, an increase in transfer factor for carbon monoxide (TLCO) or diffusing capacity for carbon monoxide (DLCO) was noted for this group of participants.

This long-term prospective study sheds light on the “natural history of childhood bronchitis into middle-age”. Nearly half of the participants had experienced at least one episode of bronchitis in their childhood. All categories of bronchitis were associated with odds of serious lung diseases such as asthma and pneumonia in adulthood. But the association was strongest for recurrent-protracted bronchitis, even though it was less prevalent. This study has clinical implications. Children with frequent bouts of protracted bronchitis should be closely monitored, up to middle age, for timely detection of subsequent asthma, pneumonia and complications such as bronchiectasis.

Reference

1. Jennifer L Perret, et al. Childhood bronchitis and respiratory outcomes in middle-age: a prospective cohort study from age 7 to 53 years. BMJ Open Respir Res. 2022 Jun;9(1):e001212. doi: 10.1136/bmjresp-2022-001212.