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Completed

NCT Number: NCT04593394

Inducible Laryngeal Obstruction in Severe Asthma in Severe Asthma

The first part will be a comparative cross-sectional study to identify the frequency of ILO and other comorbidites among participants with asthma compared to a group of reference subjects without asthma, matched for age- and gender and race.

The second part will be a longitudinally observational study study following participants for one year after the cross-sectional study. The Maat-scores ILO-symptoms and asthma-outcomes longitudinally will be evaluated, .

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Key information

Conditions

Asthma Chronic Asthma Bronchial Diseases Hypersensitivity Hypersensitivity, Immediate Immune System Diseases Laryngeal Diseases Lung Diseases Lung Diseases, Obstructive Otorhinolaryngologic Diseases Respiration Disorders Respiratory Hypersensitivity Respiratory Tract Diseases Vocal Cord Dysfunction

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Haukeland University Hospital

Bergen, 5021, Norway

About this study

Inducible laryngeal obstruction (ILO) is characterized by inappropriate closure of the structures of the larynx causing reduced airflow. The symptoms are breathing difficulties that resemble those seen in asthmatic patients, such as dyspnea, coughing and stridor. ILO may be diagnosed by the continuous laryngoscopy during exercise test (CLE-test), where the larynx is visualized live on video as the patient runs to exhaustion on a treadmill whilst having a laryngoscope placed through the nose.

The prevalence of ILO in asthmatic patients will be assesed by preforming a CLE-test twice in all participants at baseline and again after one year. Participant will be given visual feedback and instructed in breathing techniques. Others common comorbidities will be assessed by questionnaires and clinical interview. All patients with asthma will have a respiratory polygraph recording.

Changes in ILO-symptoms and asthma-symptoms and outcomes will be assessed after 1 year.

Who can participate

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with severe asthma (GINA 5)
  • Patients with mild-moderate well-treated asthma (GINA step 1-4)
  • Agroup of age- and gender matched control subjects without asthma also aged 18- 70.
  • The patients must have had a stable disease the last one month before performing the CLE-test

Exclusion criteria

  • No have underlying neurologic disease.
  • No known cancer in the lung-head-neck
  • No known vocal cord pathology.
  • No history of life-threatening asthma required hospitalization.

Treatment and study plan

Continous laryngoscopy exercise test

Diagnostic Test

Participants walks on a tredmill with a a flexible naso-laryngoscope in the larynx allowing visulasion of the larynx and obstructions in the larynx at the epiglottic og glottic levels are scored

Overnight respiratory polygraphy

Diagnostic Test

Overnight respiratory polygraphy is a continuous recording of nasal airflow, thoracic and abdominal movements, heart rate and oxygen saturation during the night used to detected sleep apnoea

Primary outcomes

  1. Prevalence of ILO in the participants

    Time frame: One year

    Continues during exercise(CLE)-test score at 2 or more at glottis or supraglottic level (Score range 0 minimum -3 maximum) 3 is full closure, 0 i open.

  2. Changes in continues during exercise (CLE-)-test score

    Time frame: One year

    The absolute change from baseline CLE-score (Score range 0 minimum -3 maximum). 3 is full closure in larynx, 0 is open.

Secondary outcomes

  1. The prevalence of OSA in asthma patients with ILO.

    Time frame: One year

    Prevalence of mild ( apnea-hypopnea index (AHI )5-15 ) moderat (AHI 15-30) and severe (AHI > 30 )OSA in participents with asthma and ILO

  2. Changes in asthma-controll score (ACT)

    Time frame: One year

    Changes of 3 points of ACT-score are considered a clinical relevant change, score (score range minimum 5, maximum 25)

  3. Number of asthma-exercabations

    Time frame: One year

    Annual asthma exacerbation rate and the precentage of patients with at least one asthma exacerbation. Asthma exacerbations are defined as worsening of asthma symptoms, and in participants on stable regimen with oral glucocorticoids, a doubling of the dose for 3 or more days or the use of systemic glucocorticoids for at least 3 days or beeing hospitalized.

  4. Changes in mini-Asthma quality of life (m-AQLQ)

    Time frame: One year

    Changes of 0.5 at m-AQLQ are considered a clinical relevant change

Sponsors and collaborators

Lead sponsor

Haukeland University Hospital

Other

Registry information

Official study title

Inducible Laryngeal Obstruction in Severe Asthma

Important dates

Study start
2020
Primary completion
2024
Study completion
2024
First posted
Oct 20, 2020
Registry last updated
Nov 21, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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