Plain English Summary
Background and study aims
Asthma is a common condition of variable airway obstruction due to inflammation, often caused by certain triggers. Obstructive sleep apnoea (OSA) is a condition in which the airway at the back of the throat is obstructed during sleep causing sufferers to snore and stop breathing. There are frequent awakenings and they never achieve a full night of good sleep. Severe sleepiness can impact enormously on their quality of life. Although both asthma and OSA are common and it would be inevitable that some patients will have both conditions, the overlap between the two seems to be more that would be expected by chance alone. This observation suggests there may be some link, possibly causative, between the two. This project aims to examine the feasibility of studying the overlap between asthma and (OSA); could asthma cause or worsen OSA? Could OSA cause or worsen asthma? We will describe various hypothetical physiological links between asthma and OSA. In addition, we will examine whether CPAP (a treatment for OSA) could have a beneficial effect on asthma?
Who can participate?
There are four groups of participant, all of which have to be at least 18: patients with OSA and asthma, asthma alone, OSA alone and healthy people with neither condition (‘control subjects’).
What does the study involve?
Patients receive appropriate standard treatment for their particular condition, which includes inhaled medication for asthma and continuous positive airways pressure (CPAP) delivered via a fitted mask over the nose at night for patients with OSA. They all have a number of breathing tests done, are asked to donate a saliva sample and complete a questionnaire about symptoms. These investigations are performed at the time of recruitment to the study for all participants. All participants are then treated with CPAP for one hour. The breathing tests are repeated one hour after the CPAP. For patients in whom it is clinically indicated (patients with OSA, with or without asthma) there is also a one month period of treatment with home CPAP. For these patients, the breathing tests and questionnaires are repeated once more after the treatment period.
What are the possible benefits and risks of participating?
The participants will not receive any immediate and direct benefits. The assessment by a specialist may lead to treatment being offered for the improvement of patients which may improve the long term lung function and thus the patient’s quality of life. In future guidelines for asthma control, it is hoped that screening for OSA in asthmatics can help in better treatment and control for asthma. There are no extra risks involved in taking part in the study, since the tests are routine and generally regarded as safe. Pulmonary function tests (PFT) are usually safe for most people. Many patients undergo the PFT without experiencing any complications. However, because the test may require patients to inhale and exhale rapidly, some patients may experience a feeling of lightheadedness. CPAP is a commonly used treatment to treat OSA in the Sleep clinic.. Side effects and other problems are usually minor, and they can be treated or fixed. Minor cases of dry mouth, nose congestion, runny nose, sneezing and sinusitis can occur. If they do the problem can usually be helped or resolved by adding a heated humidifier to the CPAP machine. All the procedures will be carried out following the current guidelines and performed only by the Respiratory and sleep consultants.
Where is the study run from?
Royal Victoria Infirmary and Freeman Hospital (UK)
When is study starting and how long is it expected to run for?
March 2015 to August 2017
Who is the main contact?
Dr. Graham Burns
Dr Graham Burns
The Chest Unit- Royal Victoria Infirmary
Queen Victoria Rd
Newcastle upon Tyne
+44 (0)191 282 0161
REC reference: 16/NE/0021, IRAS project ID: 170309
Asthma and obstructive sleep apnea. The association, physiological inter-relation and impact of therapy.
Asthma is associated with Obstructive Sleep Apnea (OSA) and the overlap between both diseases can worsen the state of patients clinically. CPAP improves OSA and can help people with asthma and OSA. We hypothesized that CPAP will improve airway physiology in people with asthma, this is because of improvements in airway physiology and/or acid reflux.
North East - Newcastle & North Tyneside 2 Research Ethics Committee, 22/03/2016, ref: 16/NE/0021
Feasibility, observational cohort study
Primary study design
Secondary study design
Feasibility, Cohort study
Patient information sheet
Not available in web format, please use contact details to request a patient information sheet
Asthma and obstructive sleep apnea (OSA)
This study aims to examine various postulated physiological links between asthma and obstructive sleep apnea.
There will be four groups of participant recruited from Respiratory and Sleep Clinics - patients with OSA and asthma, asthma alone, OSA alone and healthy people with neither condition (‘control subjects’)
Patients receive appropriate standard treatment for their particular condition: inhaled medication for asthma, continuous positive airways pressure (CPAP) delivered via a fitted mask over the nose at night for patients with OSA. Subjects will also undergo a number of breathing tests and complete a questionnaire about symptoms. For (patients with OSA, with or without asthma) there will be a one month period of treatment with home CPAP and then the breathing tests and questionnaires will be repeated.
At recruitment (for all groups (asthma only, OSA only, Asthma and OSA and healthy control)
1. Assessment of reflux symptoms
1.1. Leicester cough questionnaire
1.2. Reflux Symptoms Index Questionnaire
1.3. Saliva pepsin test
2. Lung function tests:
2.1. Exhaled Nitric Oxide
2.2. Specific airway conductance (SGaw)
2.3. Forced Expiratory Volume in 1 second ( FEV1)
2.4. Forced Expiratory Volume in 1 second Per Forced Vital Capacity (FEV1/FVC)
2.5. Forced Expiratory Flow at 50% (FEF50)
2.6. Forced Expiratory Flow at 25-75% (FEF2575)
2.7. SGaw ratio (the ratio of SGaw preceded by a deep inspiration and that without a prior deep inspiration)
3. CPAP (one hour)
4. Repeat lung function tests
For those with OSA (with or without asthma)
5. Home treatment with CPAP at night for one month. The average nightly CPAP compliance will be obtained from downloading a data card in the CPAP machine. Whilst patients are advised to aim for >4 hours a night, this may be less in the first month. Correlations of variables with CPAP compliance can be made.
One month later (only in those who have had Home CPAP). Repeat investigations
6. Assessment of reflux symptoms
6.1. Leicester cough questionnaire
6.2. Reflux Symptoms Index Questionnaire
6.3. Saliva pepsin test
7. Lung function tests:
Exhaled Nitric Oxide
7.1. Specific airway conductance (SGaw)
7.6. SGaw ratio (the ratio of SGaw preceded by a deep inspiration and that without a prior deep inspiration)
Primary outcome measure
1. The number of patients who were eligible for the study
2. The number invited to take part in the study
3. The number that entered the study
4. The number that completed the study
5. The number of patients where all observations were obtained
This information is obtained and updated at each study visit up to the end of the study.
Secondary outcome measures
1. Change in Forced Expiratory Flow 25-75 (FEF 25-75) , Specific Airway Conductance (SGaW) post 1 hour Continuous Positive Airway Pressure (CPAP) in the patient groups. Spirometry done by body plethysmography is used to calculate FEF 25-75 and SGaW. • CPAP is administered by Resmed AirSense CPAP machine. Outcomes will be measured before and after 1 hour treatment with Continuous Positive Airway Pressure (CPAP) for all participants.
2. Change in Forced Expiratory Flow 25-75 (FEF 25-75), Specific Airway Conductance (SGaW) after one month treatment with Continuous Positive Airway Pressure (CPAP) in patients receiving CPAP. Spirometry done by body plethysmography is used to calculate FEF 25-75 and SGaW. • CPAP is done by Resmed AirSense CPAP machine. Outcomes will be measured before and after 1 month treatment with Continuous Positive Airway Pressure (CPAP) for patients who will have home CPAP (i.e., patients with Obstructive Sleep Apnea (OSA) with and without asthma).
3. The prevalence of reflux; salivary pepsin, Reflux Symptom Index (RSI) questionnaire and cough (Leicester cough questionnaire) in the patient groups. • Salivary pepsin is measured by a PEPTEST (a lateral flow, near patient measurement device that measures salivary pepsin). • Reflux Symptom Index is measured by the Reflux Symptom Index questionnaire. Cough is measured by the Leicester cough questionnaire. Outcomes will be measured at recruitment for all participants. For patients who have home CPAP (i.e. patients with Obstructive Sleep Apnea (OSA) with and without asthma). Outcomes will be measured after 1 month treatment with Continuous Positive Airway Pressure (CPAP)
4. Difference in Small airway function Forced Expiratory Flow 25-75 (FEF 25-75 (Specific Airway Conductance (SGaW) between the patient groups. Spirometry done by body plethysmography is used to calculate FEF 25-75 and SGaW. Outcomes will be measured at recruitments and after 1 hour Continuous Positive Airway Pressure (CPAP) treatments for all participants. Then, they will be measured after 1 month treatment with (CPAP) for patients who will have home CPAP (i.e., patients with Obstructive Sleep Apnea (OSA) with and without asthma).
5. Fraction Exhaled Nitric Oxide (FeNO) as an index of inflammation. FeNO (Fraction Exhaled Nitric Oxide) measurements are performed with an electrochemical analyser. Outcomes will be measured at recruitment and after 1 hour Continuous Positive Airway Pressure (CPAP) treatments for all participants. They will then be measured after 1 month treatment with (CPAP) for patients who will have home CPAP (i.e., patients with Obstructive Sleep Apnea (OSA) with and without asthma).
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Control group:
1.1. Normal males or females, who are 18 years or older.
1.2. No asthma on spirometry and no bronchodilator reversibility.
1.3. No OSA on sleep study and
1.4. No other known significant clinical condition according to the clinical assessment of Dr West/Dr Burns
2. OSA group:
2.1. Males or females, who are 18 years or older.
2.2. Significant OSA on sleep study,
2.3. having empirical CPAP clinically,
2.4. no asthma on spirometry and no bronchodilator reversibility.
2.5. No other known significant clinical condition according to the clinical assessment of Dr. West/Dr. Burns
3. Asthma group:
3.1. Males or females, who are 18 years or older who have a hospital corroborated clinical diagnosis of asthma.
4. Asthma with OSA group:
4.1. Males or females, who are 18 years or older
4.2. Confirmed asthma and confirmed OSA
1. “No asthma” means: no history of asthma, normal spirometry and no bronchodilator response
2. “Asthma” means: hospital specialist respiratory physician diagnosis, with history consistent with asthma, previous obstructive spirometry, ratio <70%, minimal smoking history or normal TLCO, (± bronchodilator response if documented previously) without evidence of chronic obstructive pulmonary disease (COPD) i.e. normal gas transfer
3. Significant OSA” means: oxygen desaturation index of >10 per hour or AHI of >15 per hour on overnight sleep study
Target number of participants
Participant exclusion criteria
For all groups
1. Inability to give written informed consent in English.
2. Where a participant is already involved in other research studies or medical intervention, which might have contraindications for this study.
3. Patients regarded unfit for any other clinical reason by their respiratory or sleep physician
4. As the study involve the use of a Pulmonary Function Test (PFT), some individuals with certain conditions should not take a PFT, as it can cause problems. These conditions include:
4.1. Recent heart attack
4.2. Heart disease
4.3. Recent eye surgery
4.4. Recent chest or abdominal surgery
4.5. Respiratory infections
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
The Chest Unit- Royal Victoria Infirmary
Queen Victoria Rd
Newecastle upon tyne
Trial participating centre
Newcastle Regional Sleep Centre, Freeman Hospital
Newcastle upon Tyne
The Newcastle Upon Tyne Hospitals NHS Foundation Trusts
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Data and findings from this trial will be disseminated as widely as possible at the end of the trial. There are no plans for an interim analysis in this study.
Results will be presented in abstract form at national and international conferences to a respiratory audience e.g at the British Thoracic Society Conferences, European Respiratory Society Congress, and American Thoracic Society Conference. Following on from this we will seek to publish the research in peer reviewed medical journals. Where possible this will utilise Open Access publication strategies, to ensure a wide clinical and academic audience is reached to inform clinicians of the results and to inform future research.
IPD sharing plan
Participant level data is available on request from Dr Graham Burns (firstname.lastname@example.org)
Intention to publish date
Participant level data
Available on request
Basic results (scientific)