Clinically remitted childhood asthma is a risk factor for airflow obstruction in middle-aged adults

Background: Although several reports have investigated lung function in young adults after remission of childhood asthma, it remains unclear whether remitted childhood asthma is a risk factor for airflow obstruction in middle-aged adults. Method: A total of 10,002 subjects from 5 health check-up centers (a mean age of 49.0, range 35-60 years) were included. According to self-administered questionnaires about the presence or absence of doctor-diagnosed childhood/adulthood asthma and respiratory symptoms, subjects were classified into four categories: healthy control (HC, n=9254), remitted childhood asthma (CA, n=291), adulthood-onset asthma (AA, n=356), asthma from childhood to adulthood (CAA, n=101). Spirometric data and the prevalence of respiratory symptoms were compared between these groups. Results: The mean values of %FEV 1 and FEV 1 /FVC were significantly lower in CA, AA, and CAA groups compared with those in HC group. The prevalence of airflow obstruction were significantly higher in CA, AA and CAA groups (5.2%, 14.3%, 16.8%) when compared with HC group (2.2%). Multivariate analysis showed that remitted childhood asthma, as well as adulthood asthma, is associated with airflow obstruction. Ever-smokers of CA group had significantly reduced FEV 1 /FVC than never-smokers of CA group. Cough, sputum, dyspnea and palpitations were more frequently seen in AA and CAA groups, but not CA group, when compared with HC group. Conclusion: Clinically remitted childhood asthma, especially in smokers, is related with reduced lung function in middle-aged adults. This result suggests that childhood asthma, even when it is clinically remitted, is a risk factor of COPD.