Obstructive Sleep ApneaNCT05335083
CPAP and Glucose Metabolism in Non-Diabetic OSA Subjects
A study testing CPAP in people with Obstructive Sleep Apnea and Pre-diabetes, run by Woolcock Institute of Medical Research at 2 sites in Australia.
Trial summary
The purpose of the current study is to investigate whether alleviation of OSA by CPAP positively impacts glucose metabolism in non-diabetic patients. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obstructive Sleep Apnea, Pre-diabetes
- What is being tested?
- CPAP
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 2 sitesAustralia
- Study dates
- 1 Jul 2025to 28 Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Community dwelling adult males and females aged 18-65 years
- Polysomnography confirmed moderate to severe OSA with apnea hypopnea index (AHI) ≥15/hr within the past 60 months
- Able to give written informed consent
- Proficient in English
- 6. Diagnosed non-diabetic as defined by the American Diabetes Association as any of the following recent (<3 months) findings:
- Fasting glucose with a BGL <7.0 mmol/L
- Glucose tolerance with a 2-hour BGL of < 11.1 mmol/L after a formal 75g Oral Glucose Tolerance Test (OGTT)
- HbA1C of ≤ 6.5% 7. Possession or regular access to a mobile telephone with capability to download and run the Withings Sleep Anlayser App.
Who cannot join
- Clinically significant co-morbidity (e.g. myocardial infarction, congestive heart failure, stroke, arrythmia, chronic kidney or liver disease, epilepsy, head injury)
- Severe mental health disorders (e.g. current major depressive disorder, schizophrenia, bipolar disorder) that in the opinion of the investigator is not adequately treated or will significantly affect their participation in the study.
- Regular (>2 times per month) use of sleep-affecting medication (e.g. benzodiazepines, opioids, antidepressants)
- Regular night shift work or travel overseas within the last 2 weeks
- Sleep physician has advised against CPAP withdrawal
- Pregnancy
Show all 11Show fewer
- Active smoking or routine alcohol use (more than 2 standard drinks a day) or excessive caffeine intake (>300 mg a day) or recent (in the past month) use of illicit drugs
- Current or previous diagnosis of diabetes mellitus (previous gestational diabetes mellitus not excluded)
- Current or recent (<3 months) use of hypoglycaemic agents
- Undergoing a weight loss programme
- Contraindications for use of the FreeStyle Libre Pro Sensor. E.g. Known hypersensitivity to skin adhesives such as those used to attach the sensor to the arm.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Australia2 sites
Royal Prince Alfred Hospital
Camperdown, New South Wales, 2050
Estelle Ali, +61 468805641, estelle.ali@health.nsw.gov.au
Professor Brendon Yee
Woolcock Institute of Medical Research
Macquarie Park, New South Wales, 2113
Grigori Kaplan, PhD, +61 9114 0412, grigori.kaplan@sydney.edu.au
Craig Phillips, PhD
About this study
Official title: The Impact of CPAP on Glucose Metabolism in Moderate-Severe Obstructive Sleep Apnoea Patients Without Diabetes - An Observational Study
The purpose of the current study is to investigate whether alleviation of OSA by CPAP positively impacts glucose metabolism in non-diabetic patients.
Read the detailed description
Glucose metabolism in patients newly diagnosed with moderate-severe OSA and without diabetes will be monitored for two weeks prior to commencement of CPAP using a CGM. They will consume a 75g oral glucose drink fasted on waking twice during the two-week monitoring period, having consumed a standardised meal the evening prior. After establishing CPAP use for at least four weeks they will undergo the same protocol as for the observation period prior to commencing CPAP. Glucose metabolism will be monitored using an interstitial (skin based) glucose monitor.
- Conditions
- Obstructive Sleep Apnea, Pre-diabetes
- Being tested
- CPAP
- Medical subject headings
- Sleep Apnea, Obstructive, Glucose Intolerance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CPAPDevice
A positive CPAP intervention
| Study group | Role | What they receive |
|---|---|---|
| CPAP off condition | No intervention | Participants will be monitored for a two-week period prior to commencing CPAP. |
| CPAP on condition | Experimental | Participants will be monitored for a two-week period at least four weeks following commencement of CPAP. Receives: Device: CPAP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean 24 hour glucose difference between the CPAP on and CPAP off conditions
Average 24 hour glucose difference between CPAP on and CPAP off conditions
Measured: 2 weeks
Secondary outcomes (28)
Mean daytime glucose difference between the CPAP on and CPAP off conditions
Mean Daytime (6:00 AM - 10:00 PM) glucose difference between the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 weeks
Mean night time glucose
Mean Night-time (10:00 PM - 6:00 AM) glucose difference between the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 weeks
Glucose tolerance
Difference in glucose tolerance as measured by peak 2-hour post 75g glucose load administered twice during each two-week observation period using a CGM
Measured: 2 weeks
Coefficient of Variation
Percentage CV intraday (i.e. within 24h) and interday (i.e. over multiple days) between the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
SD of Mean Glucose
SD of Mean Glucose (daily) during the CPAP on and CPAP off conditions during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time in Range (TIR)
Percentage of TIR (3.9-10.0 mmol/L) (hours and minutes) during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time Below Range (TBR)
Percentage of TBR (3.9 mmol/L including readings of <3 .0 mmol/L) during the the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time below Range <3.0 mmol/L
Percentage of TBR <3.0 mmol/L (hours and minutes) during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time Above Range (TAR)
Percentage of TAR (>10.0 mmol/L, including readings >13.9 mmol/L) (hours and minutes) during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time Above Range >13.9 mmol/L
Percentage of TAR >13.9 mmol/L (hours and minutes) during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Time in Tight Range (TITR)
Percentage of TITR (3.9-7.8 mmol/L) (hours and minutes) during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Change in Glucose Management Indicator
Absolute main change in mmol/L or percentage during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Extended hypoglycaemic event rate
Number of events with sensor glucose <3.9 mmol/L lasting at least 120 min, event ends when glucose returns to at least 3.9 mmol/L for at least 15 minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Extended hyperglycaemic event
Number of events with sensor glucose >13.9 mmol/L lasting at least 120 min; event ends when glucose returns to 10 mmol/L or less for at least 15 minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TIR >70%
Proportion of participants with TIR 3.9-10.0 mmol/L for >70% of the day during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TIR improvement at least 5%
Proportion of participants with TIR 3.9-10.0 mmol/L with at least a 5% improvement from baseline during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TIR improvement at least 10%
Proportion of participants with TIR 3.9-10.0 mmol/L with at least a 10% improvement from baseline during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TBR <3.9 mmol/L <4%
Proportion of participants with TBR <3.9 mmol/L for <4% of each day during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TBR <3.0 mmol/L <1%
Proportion of participants with TBR <3.0 mmol/L for <1% of each day during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TAR >10.0 mmol/L >25%
Proportion of participants with a TAR >10.0 mmol/L for <25% of each day during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
TAR >13.9 mmol/L <5%
Proportion of participants with TAR >13.9 mmol/L for <5% of each day during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Hypoglycaemia
Number of times CGM sensor values are <3.9 mmol/L (including readings of <3.0 mmol/L) for at least 15 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods. The event ends when there is at least 15 consecutive minutes with a CGM sensor value at least 3.9 mmol/L.
Measured: 2 Weeks
Hypoglycaemia Alert Value (Level 1)
Number of times CGM sensor values are 3.0-3.9 mmol/L for at least 15 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods. The event ends when there is at least 15 consecutive minutes with a CGM sensor value at least 3.9 mmol/L.
Measured: 2 Weeks
Clinically Significant Hypoglycaemia (Level 2)
Number of times CGM sensor values are <3.0 mmol/L for at least 15 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods. The event ends when there is at least 15 consecutive minutes with a CGM sensor value at least 3.0 mmol/L.
Measured: 2 Weeks
Extended Hypoglycaemia
Number of times CGM sensor values are <3.9 mmol/L for at least 120 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
High Glucose Level (Level 1)
Number of times CGM sensor values are 10.1-13.9 mmol/L for at least 15 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods. The event ends when there is at least 15 consecutive minutes with a CGM sensor value at or below 10 mmol/L.
Measured: 2 Weeks
Very High Glucose (Level 2)
Number of times CGM sensor values are >13.9 mmol/L for at least 15 consecutive minutes during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods. The event ends when there is at least 15 consecutive minutes with a CGM sensor value at or below 13.9 mmol/L.
Measured: 2 Weeks
Extended Hyperglycaemia
Number of times CGM sensor values are >13.9 mmol/L for at least 90 consecutive minutes within a 120-minute period during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.
Measured: 2 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Apr 2022
- Study start1 Jul 2025 (estimated)
- Primary completion28 Feb 2027 (estimated)
- Study completion28 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obstructive Sleep ApneaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Woolcock Institute of Medical Research
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Craig L Phillips, PhD, Principal investigator, Woolcock Institute of Medical Research
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05335083
- Sponsor's protocol ID
- 2021/ETH12082
- Status last verified
- Mar 2025
- First submitted
- 12 Apr 2022
- Last updated
- 1 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: All data will be deidentified using a unique study ID.
Study at a glance
From the registry record, last updated by the sponsor on 1 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Impact of CPAP on Glucose Metabolism in Moderate-Severe Obstructive Sleep Apnoea Patients Without Diabetes - An Observational Study
- ClinicalTrials.gov ID
- NCT05335083
- Acronym / sponsor ID
- 2021/ETH12082
- Conditions
- Obstructive Sleep Apnea, Pre-diabetes
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Woolcock Institute of Medical ResearchUniversity, hospital or other
- Study start
- 1 Jul 2025 (estimated)
- Primary completion
- 28 Feb 2027 (estimated)
- Study completion
- 28 Feb 2027 (estimated)
- First posted
- 19 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the current study is to investigate whether alleviation of OSA by CPAP positively impacts glucose metabolism in non-diabetic patients.
Detailed description
Glucose metabolism in patients newly diagnosed with moderate-severe OSA and without diabetes will be monitored for two weeks prior to commencement of CPAP using a CGM. They will consume a 75g oral glucose drink fasted on waking twice during the two-week monitoring period, having consumed a standardised meal the evening prior. After establishing CPAP use for at least four weeks they will undergo the same protocol as for the observation period prior to commencing CPAP. Glucose metabolism will be monitored using an interstitial (skin based) glucose monitor.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CPAP off condition | No intervention | –Participants will be monitored for a two-week period prior to commencing CPAP. |
| CPAP on condition | Experimental | Device: CPAPParticipants will be monitored for a two-week period at least four weeks following commencement of CPAP. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Community dwelling adult males and females aged 18-65 years
- Polysomnography confirmed moderate to severe OSA with apnea hypopnea index (AHI) ≥15/hr within the past 60 months
- Able to give written informed consent
- Proficient in English
- 6. Diagnosed non-diabetic as defined by the American Diabetes Association as any of the following recent (<3 months) findings:
Key exclusion criteria (11 listed)
- Clinically significant co-morbidity (e.g. myocardial infarction, congestive heart failure, stroke, arrythmia, chronic kidney or liver disease, epilepsy, head injury)
- Severe mental health disorders (e.g. current major depressive disorder, schizophrenia, bipolar disorder) that in the opinion of the investigator is not adequately treated or will significantly affect their participation in the study.
- Regular (>2 times per month) use of sleep-affecting medication (e.g. benzodiazepines, opioids, antidepressants)
- Regular night shift work or travel overseas within the last 2 weeks
- Sleep physician has advised against CPAP withdrawal
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CPAPA positive CPAP intervention | Device | CPAP on condition |
Primary outcome
Mean 24 hour glucose difference between the CPAP on and CPAP off conditions
Time frame: 2 weeks
Average 24 hour glucose difference between CPAP on and CPAP off conditions
28 secondary outcomes
Mean daytime glucose difference between the CPAP on and CPAP off conditions
Time frame: 2 weeks
Mean night time glucose
Time frame: 2 weeks
Glucose tolerance
Time frame: 2 weeks
Coefficient of Variation
Time frame: 2 Weeks
SD of Mean Glucose
Time frame: 2 Weeks
Time in Range (TIR)
Time frame: 2 Weeks
Time Below Range (TBR)
Time frame: 2 Weeks
Time below Range <3.0 mmol/L
Time frame: 2 Weeks
Time Above Range (TAR)
Time frame: 2 Weeks
Time Above Range >13.9 mmol/L
Time frame: 2 Weeks
Time in Tight Range (TITR)
Time frame: 2 Weeks
Change in Glucose Management Indicator
Time frame: 2 Weeks
Extended hypoglycaemic event rate
Time frame: 2 Weeks
Extended hyperglycaemic event
Time frame: 2 Weeks
TIR >70%
Time frame: 2 Weeks
TIR improvement at least 5%
Time frame: 2 Weeks
TIR improvement at least 10%
Time frame: 2 Weeks
TBR <3.9 mmol/L <4%
Time frame: 2 Weeks
TBR <3.0 mmol/L <1%
Time frame: 2 Weeks
TAR >10.0 mmol/L >25%
Time frame: 2 Weeks
TAR >13.9 mmol/L <5%
Time frame: 2 Weeks
Hypoglycaemia
Time frame: 2 Weeks
Hypoglycaemia Alert Value (Level 1)
Time frame: 2 Weeks
Clinically Significant Hypoglycaemia (Level 2)
Time frame: 2 Weeks
Extended Hypoglycaemia
Time frame: 2 Weeks
High Glucose Level (Level 1)
Time frame: 2 Weeks
Very High Glucose (Level 2)
Time frame: 2 Weeks
Extended Hyperglycaemia
Time frame: 2 Weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Apr 2025.
- Individual participant dataSharing planned: No. All data will be deidentified using a unique study ID.
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A Study to Learn About the Monthly Dosing Study Medicine Called Berobenatide in Adults With Breathing Problems During Sleep and Overweight or Obesity Who Do Not Use a Breathing Machine (PAP) (VESPER-OSA 2)
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Supplemental Oxygen for Sleep-Disordered Breathing in Adults With Chronic Opioid Use.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Craig L Phillips, PhD principal investigator
Woolcock Institute of Medical Research
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CPAP in people with Obstructive Sleep Apnea and Pre-diabetes, run by Woolcock Institute of Medical Research at 2 sites in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 1 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact David J Sherring, MBBS, DClinD (0407886698, dshe7670@uni.sydney.edu.au), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean 24 hour glucose difference between the CPAP on and CPAP off conditions (time frame: 2 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Apr 2025.