Trial reportAmerican journal of respiratory and critical care medicine2012
Bronchoconstriction triggered by breathing hot humid air in patients with asthma: role of cholinergic reflex.
Trial report in American journal of respiratory and critical care medicine, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 74 papers, 3 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
74 citing papers in PubMed, 3 syntheses or guidelines pooled it, 173 citations in OpenAlex.
- Association between short-term ambient temperature variability (TV, DTR, and TCN) and asthma-related healthcare visit risk in children and adolescents: a systematic review and meta-analysis.Frontiers in public health · 2026Pooled it
- The association between ambient temperature and childhood asthma: a systematic review.International journal of biometeorology · 2018Pooled it
- Pooled it
- Effects of Using the Surgical Mask and FFP2 during the 6-Min Walking Test. A Randomized Controlled Trial.International journal of environmental research and public health · 2021Trial
- Climate Change-Mediated Temperature Extremes: Effects on the Immune System and Associations with Immune-Related Diseases.Clinical reviews in allergy & immunology · 2026Review
- Short-term exposure to heat associated with lower lung function in older adults: analysis of the Lung VITAL cohort.BMJ open respiratory research · 2026Article
- Climate change, environmental exposures, and pediatric asthma exacerbations: air pollution, temperature, and relative humidity.Pediatric research · 2026Review
- Associations of meteorological factors and obesity on pediatric asthma hospitalization.Pediatric research · 2026Article
- Quantifying the effects of air pollution on respiratory ill health treated in primary care when the locations of the populations at risk are partially unknown.Statistical methods in medical research · 2026Article
- Article
- Association between ambient temperature and respiratory health.Journal of thoracic disease · 2026Article
- Climate change and respiratory health: implications for respiratory clinicians in primary and specialist care.NPJ primary care respiratory medicine · 2026Review
- Climate change: a critical time for respiratory health.Respiratory research & clinical practice · 2026Review
- Article
- Pulmonary function responses to extreme heat exposure in younger and older adults.American journal of physiology. Regulatory, integrative and comparative physiology · 2025Article
- Impact of PMAnnals of medicine · 2025Article
- A heterogeneous-structure facial mask for thermal and humidity regulation in cold environments.Nature communications · 2025Article
- Heat Exposure Changes Lung Function, Biomarkers of Airway Injury, and Airway Microbiota: A Randomized, Crossover Trial.Environment & health (Washington, D.C.) · 2025Article
- Nasopharyngeal Airspace Temperature During Rhinothermy.Respiratory care · 2025Article
- Exercise Recommendations and Practical Considerations for Asthma Management-An EAACI Position Paper.Allergy · 2025Article
14 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 1 country.
Funding
Abstract
rationaleHyperventilation of hot humid air induces transient bronchoconstriction in patients with asthma; the underlying mechanism is not known. Recent studies showed that an increase in temperature activates vagal bronchopulmonary C-fiber sensory nerves, which upon activation can elicit reflex bronchoconstriction.
objectivesThis study was designed to test the hypothesis that the bronchoconstriction induced by increasing airway temperature in patients with asthma is mediated through cholinergic reflex resulting from activation of these airway sensory nerves.
methodsSpecific airway resistance (SR(aw)) and pulmonary function were measured to determine the airway responses to isocapnic hyperventilation of humidified air at hot (49°C; HA) and room temperature (20-22°C; RA) for 4 minutes in six patients with mild asthma and six healthy subjects. A double-blind design was used to compare the effects between pretreatments with ipratropium bromide and placebo aerosols on the airway responses to HA challenge in these patients. MEASUREMENTS AND MAIN
resultsSR(aw) increased by 112% immediately after hyperventilation of HA and by only 38% after RA in patients with asthma. Breathing HA, but not RA, triggered coughs in these patients. In contrast, hyperventilation of HA did not cause cough and increased SR(aw) by only 22% in healthy subjects; there was no difference between their SR(aw) responses to HA and RA challenges. More importantly, pretreatment with ipratropium completely prevented the HA-induced bronchoconstriction in patients with asthma.
conclusionsBronchoconstriction induced by increasing airway temperature in patients with asthma is mediated through the cholinergic reflex pathway. The concomitant increase in cough response further indicates an involvement of airway sensory nerves, presumably the thermosensitive C-fiber afferents.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.