Trial reportThorax2004
Reduced pH and chloride levels in exhaled breath condensate of patients with chronic cough.
Trial report in Thorax, 2004. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT00451841 (Exhaled Breath Condensate pH in Patients With Cough Caused by Gastroesophageal Reflux), which is not on this map. Cited by 28 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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.
Exhaled Breath Condensate pH in Patients With Cough Caused by Gastroesophageal Reflux
Who cites it
28 citing papers in PubMed, 127 citations in OpenAlex.
- Safety of an alkalinizing buffer designed for inhaled medications in humans.Respiratory care · 2013Trial
- Breath acidification in adolescent runners exposed to atmospheric pollution: a prospective, repeated measures observational study.Environmental health : a global access science source · 2008Trial
- Exhaled breath condensate pH does not discriminate asymptomatic gastroesophageal reflux or the response to lansoprazole treatment in children with poorly controlled asthma.The journal of allergy and clinical immunology. In practiceTrial
- Chloride ions in health and disease.Bioscience reports · 2024Review
- Review
- Impact of refractory and unexplained chronic cough on disease burden: a qualitative study.BMC pulmonary medicine · 2022Article
- Cystic Fibrosis and the Cells of the Airway Epithelium: What Are Ionocytes and What Do They Do?Annual review of pathology · 2022Review
- Utility of Cough Provocation Tests in Chronic Cough and Respiratory Diseases: A Comprehensive Review and Introduction of New Reference Ranges for the Capsaicin Test.Allergy, asthma & immunology research · 2021Review
- Living near a Major Road in Beijing: Association with Lower Lung Function, Airway Acidification, and Chronic Cough.Chinese medical journal · 2016Article
- Article
- Exhaled Breath Condensate: Technical and Diagnostic Aspects.TheScientificWorldJournal · 2015Review
- Approach to chronic cough: the neuropathic basis for cough hypersensitivity syndrome.Journal of thoracic disease · 2014Review
- Review
- Exhaled breath condensate--from an analytical point of view.Biochemia medica · 2013Review
- Biomarkers for gastroesophageal reflux in respiratory diseases.Gastroenterology research and practice · 2013Article
- Exhaled breath condensate pH in patients with cystic fibrosis.Inflammation research : official journal of the European Histamine Research Society ... [et al.] · 2012Article
- Chronic cough and OSA: a new association?Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2011Review
- Cough and Asthma.Current respiratory medicine reviews · 2011Article
- Levels of Exhaled Breath Condensate pH and Fractional Exhaled Nitric Oxide in Retired Coal Miners.Toxicological research · 2010Article
- Magnesium and calcium in exhaled breath condensate of children with asthma and gastroesophageal reflux disease.Journal of clinical laboratory analysis · 2009Article
Corrections and comments
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Authors and funding
5 authors at 1 institution in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIncreased hydrogen and reduced chloride ionic environments of the airways are conducive to the stimulation of cough. However, the constituents of the local milieu of the airways of patients with chronic cough are unknown.
methodsThe pH and chloride levels in exhaled breath condensate and capsaicin cough threshold (C5) were measured in 50 patients with chronic cough and in 16 healthy controls. pH and chloride measurements were repeated after capsaicin challenge in those with cough. The cause of cough was asthma (n = 13), postnasal drip/rhinitis (n = 7), gastro-oesophageal reflux (n = 5), bronchiectasis (n = 5), but remained unidentified in 20.
resultsCompared with controls, patients with chronic cough had lower pH (mean 7.9 v 8.3, 95% CI of difference -0.5 to -0.2, p<0.0001), chloride levels (median 4 v 6 mmol/l, 95% CI -3.1 to -0.2, p = 0.007), and C5 (median 3.9 v 125 micro M, 95% CI -270.0 to -17.6, p = 0.002). The pH levels were different in the six subgroups including controls, and were reduced in all diagnostic subgroups of patients with cough compared with controls but did not differ between them. Chloride levels were significantly different in the six subgroups but were lower than controls in only the gastro-oesophageal reflux subgroup. There was a weak but significant correlation between chloride levels and C5 when all participants were analysed together, but not between pH and C5 or chloride levels. pH and chloride levels did not change after capsaicin challenge.
conclusionsThe epithelial lining fluid of patients with chronic cough has a reduced pH and reduced chloride levels which could contribute to the enhanced cough reflex.
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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.