Investigating air cleaner benefits for overweight versus normal weight asthma
Published online July 3, 2025
With children spending as much as 90% of their time indoors, poor indoor air quality poses a major risk to the respiratory health of children with asthma. Observational studies have suggested that overweight and obese children are more susceptible to the harms of indoor air pollution than normal weight children. Targeted interventions to improve home air quality may be a strategy to improve asthma management. Prior clinical studies have explored using air cleaners with high efficiency particulate air filters (HEPA) to reduce indoor air pollution, and many studies have reported that air cleaner use is associated with improvement in asthma symptoms. In a recently published article in The Journal of Allergy and Clinical Immunology: In Practice, Qiu et al. sought to explore the relationship of body weight and susceptibility to air pollution and to determine if overweight children derive a greater benefit from air cleaners compared to normal weight children.
The AIRWEIGHS study is a randomized, placebo-controlled clinical trial that was conducted in Baltimore, MD with children ages 8-17 years with asthma. 164 normal weight and overweight/obese children, classified by body mass index (BMI), were randomly assigned to receive either air cleaners with working HEPA filters or air cleaners with placebo filters to place in their homes to use continuously for 12 weeks. Indoor air pollution levels and asthma questionnaires that assess asthma symptoms and control were collected at baseline and after 12 weeks of the intervention.
The study showed that using home air cleaners with HEPA filters for 12 weeks led to lower levels of many indoor air pollutants. Ultrafine and fine particles were reduced by over 50% in the HEPA air cleaner group. On average, all children demonstrated improved asthma symptoms over the 12-week course of the study. However, there were no difference in asthma status between children who received HEPA filter air cleaners compared to children who received placebo air cleaners. Moreover, there was no difference in asthma outcomes between overweight children and normal weight children. The authors propose that many factors, such as the short length of 12 weeks and a small sample size, may have obscured the positive benefit of air cleaners that previous studies reported. Clinicians can make recommendations for home air cleaner use in asthma patients on an individual basis. This study highlights the importance of future research on the relationship between the negative impact of air pollution and body weight, and the need for thoughtfully designed air cleaner trials to explore the benefit for patients with asthma.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
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