Reduced Diffusing Capacity in Humidifier Disinfectant-Associated Asthma Versus Typical Asthma: A Retrospective Case...

Area of Science:

• Pulmonary Medicine
• Toxicology
• Occupational Health

Background:

• Humidifier disinfectant-related lung injury (HDLI) is severe lung damage from guanidine-based compounds in humidifier disinfectants (HD).
• HD-associated asthma (HDA) presents with asthma-like symptoms, likely due to airway injury from HD exposure.
• This study investigates diffusing capacity of the lung for carbon monoxide (DLCO) in HDA patients compared to those with pre-existing asthma without HD exposure.

Purpose of the Study:

• To compare DLCO values between patients with HDA and a control group of asthma patients without HD exposure.
• To identify the relationship between HD exposure and DLCO levels.
• To explore the role of forced vital capacity (FVC) in mediating the effect of HD exposure on DLCO.

Main Methods:

• Retrospective comparison of DLCO data from 70 HDA patients and 79 control asthma patients.
• Multivariable and logistic regression analyses to assess the association between HD exposure and DLCO, controlling for confounders.
• Correlation analysis to evaluate the relationship between DLCO and indicators of HD exposure.

Main Results:

• Mean DLCO was significantly lower in the HDA group (81.9%) compared to controls (88.6%) (P=0.021).
• Lower DLCO was observed with increasing HD exposure severity (P for trend = 0.002).
• HDA patients had 2.1-fold higher likelihood of lower DLCO, with a 5.8% decrease in DLCO in multivariable models; decreased FVC partially mediated this effect.

Conclusions:

• Patients with HDA exhibit significantly reduced DLCO compared to asthma patients without HD exposure.
• Decreased FVC plays a partial role in the reduced DLCO observed in HDA.
• DLCO monitoring is a potentially valuable tool for early HDA diagnosis in at-risk individuals.