Frequency of exacerbation and degree of required asthma medication can characterize childhood longitudinal asthma trajectories

Early childhood lower-airway symptoms and airway hyperresponsiveness linked to school-age small-airway dysfunction

Background

The role of early airway hyperresponsiveness (AHR) in the subsequent small-airway lung function remains unclear.

Objective

We assessed via a prospective follow-up study the small-airway lung function of schoolchildren with early childhood lower-airway symptoms and AHR to methacholine and compared the findings to the measurements of reference children with no previous or current lung diseases.

Methods

During 2004-11, we measured atopic markers, lung function, and airway responsiveness to methacholine in 193 symptomatic children <3 years old. In 2016-18, a follow-up sample of 84 schoolchildren and 40 reference children were assessed for atopic parameters, spirometry, and small-airway lung function. Analysis was performed on the basis of early childhood AHR, early childhood atopy (defined as a positive skin prick test result), and exposure to parental smoking reported in a questionnaire. All the results were compared with those of the reference group.

Results

Schoolchildren with early childhood lower-airway symptoms and AHR had higher prebronchodilator area under the reactance curve (AX) z score, lower forced expiratory flow at 50% of forced vital capacity (FEF50%) z score, and higher lung clearance index (LCI) 2.5% compared with those without early childhood AHR and reference children. Moreover, AX and FEF50% z scores only partly improved after bronchodilation. Early childhood atopy and exposure to parental smoking were not associated with school-age small-airway dysfunction.

Conclusion

AHR in symptomatic young children associated with subsequent persistent small-airway dysfunction. Further studies with larger samples of symptomatic young children are warranted to determine whether this connection predicts the development of asthma or other obstructive pulmonary diseases as the children grow.

Trends in the Prevalence of Asthma in Korean Children: A Population-Based Study From 1995 to 2022

PURPOSE

We investigated the prevalence of asthma and its risk factors in Korean children in 2022, comparing the prevalence with previous data to identify trends in the prevalence of childhood asthma over time.

METHODS

This nationwide cross-sectional study enrolled 4,038 children aged 6-7 years and 4,269 children aged 12-13 years from 213 randomly selected elementary schools in 2022. The prevalence of asthma in 2022 was compared with those in 1995, 2000, and 2010, with subgroup comparisons classified by gender. A modified International Study of Asthma and Allergies in Childhood questionnaire assessed asthma prevalence with environmental factors.

RESULTS

The prevalence of ''asthma diagnosis ever' in children aged 6-7 years was 9.1%, 9.4%, and 10.4% in 1995, 2000, and 2010, respectively, which was decreased in 2022 (2.1%, P < 0.001). The prevalence of 'current asthma' in children aged 6-7 years showed fluctuations (3.5%, 2.0%, 4.2%, and 0.6% in 1995, 2000, 2010, and 2022, respectively) without showing a significant trend. The prevalence of 'asthma diagnosis ever' and 'current asthma' in children aged 6-7 years was significantly higher in males than in females. The prevalence of 'asthma diagnosis ever' in children aged 12-13 years was 3.1% in 1995, with a significant increasing trend in 2000 (5.8%) and 2010 (7.5%), followed by a decrease in 2022 (3.4%). Male sex, a history of bronchiolitis in early life, allergic rhinitis diagnosis ever, and atopic dermatitis diagnosis ever were associated with 'asthma diagnosis ever' in children aged 6-7 years. For children aged 12-13 years, male sex and history of bronchiolitis in early life were independently associated with 'asthma diagnosis ever.'

CONCLUSIONS

Childhood asthma prevalence has decreased, varying by asthma definition. The study's findings provide important information for establishing prevention and management strategies of childhood asthma.

Association of Wheezing Requiring Hospitalization Before 2 Years of Age With Autoimmune Diseases During Childhood: A 15-Year Follow-up Study From Birth

PURPOSE

Wheezing in early life is most frequently caused by viral lower respiratory tract illnesses, constituting a significant disease burden in children. This study aimed to investigate the association of wheezing in early life with autoimmune diseases throughout childhood.

METHODS

A population-matched retrospective cohort study was conducted in Korea between 2002 and 2017. The cohort comprised 34,959 children admitted with viral wheezing before 2 years of age and an equal number of the matched unexposed children born in 2002 and 2003. Exposed infants were defined as those hospitalized for bronchiolitis or bronchial asthma before the age of 2. Unexposed controls were matched by sex and birth year at a 1:1 ratio, using incidence density sampling. A Cox proportional hazard model controlled for multiple risk factors was employed.

RESULTS

The median age at hospitalization for wheeze was 9 months (interquartile range, 5-15 months), and 63% of the exposed infants were male. Over the mean 15-year follow-up period, the incidence rate of autoimmune diseases was 74.0 and 62.2 per 10,000 person-years in the exposed and matched unexposed cohorts, respectively. The adjusted hazard ratio for any autoimmune disease in the exposed cohort was 1.15 (95% confidence interval, 1.09-1.23) in comparison with the unexposed cohort. The exposed cohort revealed an augmented risk for specific autoimmune diseases, including juvenile idiopathic arthritis, Kawasaki disease, Henoch-Schönlein purpura, psoriasis, idiopathic thrombocytopenic purpura, and immunoglobulin A nephropathy. Risks were heightened for children with multiple wheezing episodes or a persistent wheezing episode after the age of 2 years.

CONCLUSIONS

This research identifies associations between early-life wheeze and the development of autoimmune diseases in childhood. Understanding these relationships can aid in recognizing the underlying pathophysiology of early-life wheeze and childhood autoimmune diseases, contributing to management strategies for these conditions.