Rationale: Exposure to humidifier disinfectants (HDs) can increase the risk of asthma, but the characteristics of HD-related asthma are currently unclear. Polyhexamethylene guanidine (PHMG)-containing HD was the most commonly used and the most frequently associated with HD-associated lung injury. Objectives: To investigate the characteristics of PHMG-induced asthma. Methods: This general population-based birth cohort study used data from the Panel Study of Korean Children from 2008 (n = 846). Spirometry, bronchial provocation tests, detailed history recording, and physical examinations were performed on 7-year-old patients (n = 362). Exploratory analysis of plasma proteomics was performed. Results: Compared with the healthy control group, forced expiratory volume in 1 second was the lowest in PHMG-exposed asthma group (z-score = -0.806; 95% confidence interval, -1.492 to -0.119). The positive rate of bronchial hyperresponsiveness was lower in children with PHMG-exposed asthma compared with children with asthma without HD exposure (13.3% vs. 47.4%). Long-term exposure to low-intensity PHMG before the age of 3 years was associated with asthma symptoms. Periostin was higher in subjects with asthma without HD exposure compared with the healthy control subjects. The inducible T-cell costimulator ligand and hepatocyte growth factor activator were lower in PHMG-exposed asthma compared with asthma without exposure. Hepatocyte growth factor activator had a positive correlation with forced vital capacity (z-score) in asthma with PHMG exposure (r = 0.78; P < 0.01). Conclusions: The asthma associated with low-intensity exposure to PHMG is characterized by lower lung function, lower positive rates of bronchial hyperresponsiveness, and varied distributions of plasma proteins. These findings suggest that asthma related to PHMG exposure may constitute a different mechanism of asthma pathophysiology.
Keywords: children; environmental exposure; lung function; proteomics.