Condition category
Respiratory
Date applied
27/07/2020
Date assigned
24/08/2020
Last edited
24/08/2020
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Exercise-induced dyspnea (shortness of breath) in athletes is common and is often attributed to asthma. However, all wheeze is not due to asthma and diagnosis and treatment should be based on careful clinical evaluation. Exercise-induced laryngeal obstruction (EILO) is an important differential diagnosis to asthma in athletes. In EILO, the larynx (voice box) is transiently obstructed during exercise resulting in decreased airflow and airway symptoms, typically with a sudden onset followed by rapid cessation when exercise is stopped. EILO is diagnosed with a continuous laryngoscopy during exercise (CLE) test, in which larynx is continuously visualized during peak exercise. This study aims to estimate the prevalence of EILO among athletes and to describe the natural history of EILO. Secondary aims of the study are to describe the prevalence of asthma and to what extent the conditions coexist.

Who can participate?
Healthy athletes at competitive level, 15-35 years of age

What does the study involve?
Participation in the study involves one or two visits at the Clinical Research Centre, where testing is done. Each visit includes a clinical examination by a physician, spirometry (lung function tests), asthma provocation test with a eucapnic voluntary hyperventilation test (EVH), skin prick test (only first visit), questionnaire, and continuous laryngoscopy during exercise (CLE) test.

What are the possible benefits and risks of participating?
The participants receive financial compensation of about £90 (SEK 1000). The pre-test requires exercise to exhaustion which may be uncomfortable for participants who do not frequently undertake high-intensity exercise. Oxygen uptake is measured using a mouthpiece and nose clip that might cause a little discomfort during exercise. Exposure to sub-zero temperatures is expected to cause short-lived cold-related symptoms. Blood sampling causes short-lived pain at the site of vein puncture. The lung function tests involve several large exhalations which may feel exhaustive in the moment.

Where is the study run from?
Clinical Research Centre, Östersund Hospital (Sweden)

When is the study starting and how long is it expected to run for?
April 2014 to November 2017

Who is funding the study?
1. VISARE NORR Fund, Northern Country Councils Regional Federation (Sweden)
2. Unit of Research, Education and Development, Region Jämtland Härjedalen (Sweden)

Who is the main contact?
1. Dr Tommie Irewall (public)
tommie.irewall@umu.se
2. Dr Nikolai Stenfors (scientific)
nikolai.stenfors@umu.se

Trial website

Contact information

Type

Public

Primary contact

Dr Tommie Irewall

ORCID ID

https://orcid.org/0000-0002-8821-2352

Contact details

Östersund Hospital
Kyrkgatan 16
Östersund
83183
Sweden
+46 (0)63 153000
tommie.irewall@umu.se

Type

Scientific

Additional contact

Dr Nikolai Stenfors

ORCID ID

https://orcid.org/0000-0002-1684-1301

Contact details

Östersund Hospital
Kyrkgatan 16
Östersund
83183
Sweden
+46 (0)63 153000
nikolai.stenfors@umu.se

Additional identifiers

EudraCT number

Nil known

ClinicalTrials.gov number

Nil known

Protocol/serial number

EILO hos konditionsidrottare.

Study information

Scientific title

Prevalence of exercise-induced laryngeal obstruction and asthma among athletes

Acronym

Study hypothesis

Athletes have a high prevalence of exercise-induced laryngeal obstruction (EILO).

Ethics approval

Approved 26/03/2015, Regional Ethical Review Board Umea (Samverkanshuset Universitetsområdet, 901 87 Umeå, Sweden; +46 (0)90 786 7252; epn@adm.umu.se), ref: Dnr 2015-43-31M

Study design

Single-center longitudinal cohort study

Primary study design

Observational

Secondary study design

Cohort study

Trial setting

Hospitals

Trial type

Screening

Patient information sheet

Not available in web format, please use the contact details to request a participant information sheet

Condition

Prevalence of exercise-induced laryngeal obstruction (EILO) in athletes

Intervention

Participants undergo a clinical examination by the study physician, dynamic spirometry, eucapnic voluntary hyperventilation test, skin prick test, and continuous laryngoscopy during exercise test (CLE). CLE test includes running on a treadmill at incrementing speed to >90% maximum heart rate, while video recording larynx with a nasal fiberscope.

Intervention type

Other

Phase

Drug names

Primary outcome measure

Prevalence and natural history of exercise-induced laryngeal obstruction (EILO), defined as laryngeal obstruction at glottic or supraglottic level using a visual scoring system, assessed with continuous laryngoscopy during exercise test (CLE), at the first and second visit (summer or winter season)

Secondary outcome measures

1. Current asthma, defined as a) physician-diagnosed asthma, and b) use of asthma medication in the last 12 months, evaluated by questionnaire at first visit
2. Bronchial hyperreactivity, defined as 10% decrease in FEV1 after EVH test, measured at the first and second visit (summer or winter season)
3. Allergy, defined as a) reaction with >2 mm wheal to skin prick test, and b) self-reported allergic symptoms, measured at first visit

Overall trial start date

26/04/2014

Overall trial end date

28/11/2017

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

1. Competitive athlete ( i.e. not at recreational level)
2. Age 15-35 years

Participant type

Healthy volunteer

Age group

Mixed

Gender

Both

Target number of participants

100

Total final enrolment

111

Participant exclusion criteria

1. Pregnancy
2. FEV1 <50% of expected value at spirometry
3. Blood pressure (mmHg) > 200 systolic or >100 diastolic at rest
4. Aortic aneurysm
5. Previous heart attack or stroke

Recruitment start date

07/04/2015

Recruitment end date

28/11/2017

Locations

Countries of recruitment

Sweden

Trial participating centre

Clinical Research Centre, Östersund Hospital
Kyrkgatan 16
Östersund
831 83
Sweden

Sponsor information

Organisation

Umeå University

Sponsor details

Umeå
Umeå
SE-901 87
Sweden
+46 (0)90 786 50 00
umea.universitet@umu.se

Sponsor type

University/education

Website

http://www.umu.se/english

Funders

Funder type

Government

Funder name

VISARE NORR Fund, Northern Country Councils Regional Federation

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Unit of Research, Education and Development, Region Jämtland Härjedalen

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Planned publications in peer-reviewed journals. Additional documents may be made available upon request.

IPD sharing statement
The data generated during and/or analysed during the current study are not expected to be made available due to a requirement in the ethical approval, where there is a statement that the data will not be shared with unauthorized persons. The data will be held in a server at Umeå University.

Intention to publish date

30/10/2020

Participant level data

Not expected to be available

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

28/07/2020: Trial's existence confirmed by Regional Ethical Review Board Umea.