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Trial details imported from

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Registration number
Ethics application status
Date submitted
Date registered
Date last updated

Titles & IDs
Public title
Reference Ranges for the Cough Responsiveness to Inhaled Mannitol
Scientific title
Reference Ranges for the Cough Responsiveness to Inhaled Mannitol
Secondary ID [1] 0 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cough 0 0
Condition category
Condition code
Respiratory 0 0 0 0
Other respiratory disorders / diseases

Study type
Description of intervention(s) / exposure
Diagnosis / Prognosis - Mannitol challenge

Experimental: Healthy persons - The responses of the healthy subjects are utilized to create reference ranges for a normal cough response to mannitol

Diagnosis / Prognosis: Mannitol challenge
Inhalation challenge with dry powder of mannitol with a maximal cumulative dose of 635 mg

Intervention code [1] 0 0
Diagnosis / Prognosis
Comparator / control treatment
Control group

Primary outcome [1] 0 0
Cough-to-dose ratio - calculated as the number of coughs per 100 mg of total cumulative dose of mannitol
Timepoint [1] 0 0
Coughs are recorded during the 60 seconds after each mannitol dose

Key inclusion criteria
- age 18 years or older

- capable to understand the purpose of the study

- female/male ratio approximately 50%/50% in both of the following age groups:

- 50% aged 18- 50 yrs, and 50 % aged 51 - 90 years
Minimum age
18 Years
Maximum age
90 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
- Current daily smoking

- Ex-smoking with a greater than 10 pack years' daily smoking history or with stopping
of daily smoking less than one year ago

- Pregnancy and breastfeeding

- A doctor's diagnosis of any respiratory diseases, including both upper and lower
airway diseases, lung parenchymal diseases and the sleep apnoea syndrome

- A doctor's diagnosis of gastro-oesophageal reflux disease or symptoms suggestive of it

- Current use of angiotensin-converting enzyme inhibitors

- Upper respiratory tract infection ('flu') within 4 weeks

- Any current (within 4 weeks) cough 8

- Chronic (over 2 months' duration) cough during the last 12 months

- Wheezing during the last 12 months

- Attacks of shortness of breath or cough at night during the last 12 months

- Symptoms of rhinitis in a prolonged fashion during the last 12 months

- Heartburn or regurgitation once a week or more often during the last 3 months

- Abnormal anatomy of the respiratory organs, which may affect the deposition of the
mannitol powder

- Any previous operations to the respiratory organs that can affect the deposition of
the mannitol powder

- Unable to provide written informed consent to participate in the study

Study design
Purpose of the study
Allocation to intervention
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 0 0
John Hunter Hospital - Newcastle
Recruitment hospital [2] 0 0
Royal Prince Alfred Hospital - Sydney
Recruitment postcode(s) [1] 0 0
2305 - Newcastle
Recruitment postcode(s) [2] 0 0
2050 - Sydney
Recruitment outside Australia
Country [1] 0 0
State/province [1] 0 0

Funding & Sponsors
Primary sponsor type
Kuopio University Hospital
Other collaborator category [1] 0 0
Name [1] 0 0
John Hunter Hospital
Address [1] 0 0
Country [1] 0 0
Other collaborator category [2] 0 0
Name [2] 0 0
Royal Prince Alfred Hospital, Sydney, Australia
Address [2] 0 0
Country [2] 0 0

Ethics approval
Ethics application status

Brief summary
Cough is the most common reason why people seek medical attention in developed countries. The
main mechanisms for prolonged cough are hypersensitivity of the cough reflex arc, sputum
production, and constriction of the airway smooth muscles. Recognition of the mechanism in
each cough patient is essential for the efficient management of prolonged cough. At present,
there are no feasible tests for everyday clinical work to recognize cough reflex arc

Mannitol test was originally developed for asthma diagnostics. We have recently shown that it
can also be used to investigate hypersensitive cough reflex arc. The purpose of the present
study is to create reference ranges for normal cough responsiveness to inhaled mannitol.
Without them, the test cannot be utilized in everyday clinical work. For that purpose we will
perform mannitol test in 140 subjects, who are at least 18 years old and without any chronic
respiratory symptoms or disorders. The subjects will be recruited in three centers:
University of Eastern Finland and two Australian hospitals: John Hunter Hospital and Royal
Prince Alfred Hospital.The material will be collected 1.9.2021-31.12.2022. We apply funding
for both personnel and material expences, to carry out this study.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Heikki O Koskela, MD
Address 0 0
Country 0 0
Phone 0 0
+358 447172795
Fax 0 0
Email 0 0
Contact person for scientific queries

Summary results
For IPD and results data, please see