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NCT Number: NCT05335083

CPAP and Glucose Metabolism in Non-Diabetic OSA Subjects

The purpose of the current study is to investigate whether alleviation of OSA by CPAP positively impacts glucose metabolism in non-diabetic patients.

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Key information

Conditions

Obstructive Sleep Apnea Apnea Dyssomnias Glucose Intolerance Glucose Metabolism Disorders Hyperglycemia Metabolic Diseases Nervous System Diseases Nutritional and Metabolic Diseases Pre-diabetes Respiration Disorders Respiratory Tract Diseases Sleep Apnea Syndromes Sleep Apnea, Obstructive Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia

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About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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
  • 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.

Exclusion criteria

  • 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
  • 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.

Treatment and study plan

CPAP

Device

A positive CPAP intervention

Primary outcomes

  1. 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

Secondary outcomes

  1. Mean daytime glucose difference between the CPAP on and CPAP off conditions

    Time frame: 2 weeks

    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.

  2. Mean night time glucose

    Time frame: 2 weeks

    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.

  3. Glucose tolerance

    Time frame: 2 weeks

    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

  4. Coefficient of Variation

    Time frame: 2 Weeks

    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.

  5. SD of Mean Glucose

    Time frame: 2 Weeks

    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.

  6. Time in Range (TIR)

    Time frame: 2 Weeks

    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.

  7. Time Below Range (TBR)

    Time frame: 2 Weeks

    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.

  8. Time below Range <3.0 mmol/L

    Time frame: 2 Weeks

    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.

  9. Time Above Range (TAR)

    Time frame: 2 Weeks

    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.

  10. Time Above Range >13.9 mmol/L

    Time frame: 2 Weeks

    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.

  11. Time in Tight Range (TITR)

    Time frame: 2 Weeks

    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.

  12. Change in Glucose Management Indicator

    Time frame: 2 Weeks

    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.

  13. Extended hypoglycaemic event rate

    Time frame: 2 Weeks

    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.

  14. Extended hyperglycaemic event

    Time frame: 2 Weeks

    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.

  15. TIR >70%

    Time frame: 2 Weeks

    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.

  16. TIR improvement at least 5%

    Time frame: 2 Weeks

    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.

  17. TIR improvement at least 10%

    Time frame: 2 Weeks

    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.

  18. TBR <3.9 mmol/L <4%

    Time frame: 2 Weeks

    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.

  19. TBR <3.0 mmol/L <1%

    Time frame: 2 Weeks

    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.

  20. TAR >10.0 mmol/L >25%

    Time frame: 2 Weeks

    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.

  21. TAR >13.9 mmol/L <5%

    Time frame: 2 Weeks

    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.

  22. Hypoglycaemia

    Time frame: 2 Weeks

    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.

  23. Hypoglycaemia Alert Value (Level 1)

    Time frame: 2 Weeks

    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.

  24. Clinically Significant Hypoglycaemia (Level 2)

    Time frame: 2 Weeks

    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.

  25. Extended Hypoglycaemia

    Time frame: 2 Weeks

    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.

  26. High Glucose Level (Level 1)

    Time frame: 2 Weeks

    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.

  27. Very High Glucose (Level 2)

    Time frame: 2 Weeks

    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.

  28. Extended Hyperglycaemia

    Time frame: 2 Weeks

    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.

Other outcomes

  1. TIR Improvement >10% and <0.5% increase in TBR <3.0 mmol/L

    Time frame: 2 Weeks

    Proportion of participants with >10% improvement in percentage of TIR 3.9-10.0 mmol/L without an increase in the TBR <3.0 mmol/L of >0.5% during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.

  2. Mean Glucose <8.6 mmol/L and <1% TBR <3.0 mmol/L

    Time frame: 2 Weeks

    Proportion of participants with Mean Glucose <8.6 mmol/L and < 1% TBR <3.0 mmol/L during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.

  3. TIR >70% and <1% TBR <3.9 mmol/L

    Time frame: 2 Weeks

    Proportion of participants with >70% TIR 3.9-10.0mmol/L and <4% TBR <3.9 mmol/L during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.

  4. TIR >70% and < 1% TBR <3.0 mmol/L

    Time frame: 2 Weeks

    Proportion of participants with >70% TIR 3.9-10.0 mmol/L and <1% TBR <3.0 mmol/L during the CPAP on and CPAP off conditions as measured by the FreeStyle Libre Pro sensor during the 2-week intervention periods.

Study contacts

Contact information is provided by the study sponsor or research team.

David J Sherring, MBBS, DClinD

CONTACT

[email protected]

0407886698

Sponsors and collaborators

Lead sponsor

Woolcock Institute of Medical Research

Other

Registry information

Official study title

The Impact of CPAP on Glucose Metabolism in Moderate-Severe Obstructive Sleep Apnoea Patients Without Diabetes - An Observational Study

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Apr 19, 2022
Registry last updated
Apr 1, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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