Clinical trial NCT04593394: Inducible Laryngeal Obstruction in Severe Asthma in Severe Asthma
Official title: Inducible Laryngeal Obstruction in Severe Asthma
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Asthma Chronic
Vocal Cord Dysfunction
Keywords: Inducible laryngeal dysfunction, Severe asthma,
Lead sponsor: Haukeland University Hospital
Sponsor class: OTHER
First posted: 2020-10-20
Enrollment: 160
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The sample size of the cohort with severe asthma will be: All patients with severe asthma followed in our clinic for severe asthma estimated to be around 80 participants, of them, we hope to recruit at least 40 to perform the CLE-test, and we plan to recruit 40 participants with mild asthma and 40 age- and gender matched control subjects without asthma

Brief summary: 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, .

Detailed description: 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Prevalence of ILO in the participants
timeFrame: One year
measure: Changes in continues during exercise (CLE-)-test score
timeFrame: One year
Secondary outcomes:
measure: The prevalence of OSA in asthma patients with ILO.
timeFrame: One year
measure: Changes in asthma-controll score (ACT)
timeFrame: One year
measure: Number of asthma-exercabations
timeFrame: One year
measure: Changes in mini-Asthma quality of life (m-AQLQ)
timeFrame: One year
Other outcomes:
Locations:
city: Bergen
country: Norway
facility: Haukeland University Hospital
Study officials:
affiliation: Haukeland University Hospital
name: Sverre Lehmann, PhD
role: PRINCIPAL_INVESTIGATOR
References: