Exposure to very dry air collapses airway mucus, but an inhaled magnesium mist could help protect the respiratory tract.
RT’s Three Key Takeaways:
- Airway Mucus Collapse: Very dry atmospheric air causes protective airway mucus to collapse onto cilia, triggering cough sensitivity in a manner similar to chronic respiratory diseases such as cystic fibrosis and asthma.
- Clinical Trial Results: In a randomized, double-blind, placebo-controlled study of patients with refractory chronic cough, an alkaline magnesium salt aerosol produced a 59% placebo-adjusted reduction in daily cough episodes, with relief persisting for one to three weeks.
- Nonpharmacological Treatment Strategy: Targeted rehydration of the respiratory tract using optimized mineral salt aerosols presents a potential nondrug intervention to mitigate cough and protect vulnerable patient populations during periods of severe aridity and heatwaves.
Extremely dry air during heatwaves can heighten airway sensitivity and trigger coughing by dehydrating mucus, but a nonpharmacological magnesium salt aerosol may provide sustained relief, according to a study published in Nature Scientific Reports.
The study, led by researchers at the University of North Carolina (UNC) School of Medicine in collaboration with SC Therapeutics, Imperial College London, and Boston University, examined the physical impact of atmospheric aridity on respiratory health.
Investigators observed that very dry air causes mucus in the airway passages to collapse directly onto cilia, the microscopic hair-like structures responsible for airway clearance, the study authors reported. This mucosal collapse resembles the pathology observed in chronic lung conditions, including cystic fibrosis and asthma, which heightens cough sensitivity and can worsen respiratory distress in hot, arid weather and low-humidity indoor environments.
Rehydrating Airway Mucus
To reverse this dehydration, researchers evaluated an alkaline aerosol formulated with magnesium salts designed to rehydrate airway mucus. Inhalation of the aerosol successfully reversed mucus collapse for several hours and reduced overall cough sensitivity.
The researchers evaluated the therapy in a randomized, double-blind, placebo-controlled trial of 10 patients diagnosed with refractory chronic cough, where the magnesium salt aerosol demonstrated a placebo-adjusted reduction in daily cough episodes of 59% (P = .03), the study reported. Clinical benefits continued for one to three weeks following the treatment period.
“Hypertonic salts have long been used to treat cystic fibrosis, a genetic condition of dehydrated airways,” said Brian Button, PhD, professor of biochemistry and biophysics at the UNC School of Medicine, in a news release. “This study gives evidence that new kinds of hypertonic salts, longer acting and rendered therapeutic by optimization of rehydration processes within mucus we are only beginning to discover, might provide prophylaxis and treatment options for a human population previously spared the damages of mucosal dehydration.”
Environmental Aridity and Clinical Implications
The findings indicate that exposure to dehydrated air is increasingly frequent due to urbanization, indoor climate control, and rising heatwave occurrences, according to the study authors. While air pollution typically triggers respiratory inflammation through toxic chemical gases and fine particulates, atmospheric dryness induces inflammation directly through rapid mucosal water loss.
Targeted airway rehydration using optimized magnesium salt aerosols could provide healthcare providers with a nondrug approach to manage chronic coughing and protect vulnerable respiratory patients during periods of severe environmental dryness, the authors concluded.
