Obstructive Sleep ApneaHBO-POSANCT07809061
Hypercapnic Burden in Adults With Obesity Undergoing Diagnostic Polysomnography for Suspected Obstructive Sleep Apnea
A study testing Sleep Inertia Questionnaire (SIQ) in people with Obstructive Sleep Apnea and Obesity (BMI>30), run by Hospices Civils de Lyon at 1 site in France.
Trial summary
Obesity-related sleep hypoventilation represents a continuum ranging from isolated nocturnal hypoventilation to obesity hypoventilation syndrome. Current diagnostic criteria rely mainly on dichotomous thresholds and may not adequately reflect cumulative nocturnal carbon dioxide exposure. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obstructive Sleep Apnea, Obesity (BMI>30), Obesity Hypoventilation Syndrome (OHS)
- What is being tested?
- Sleep Inertia Questionnaire (SIQ)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 1 siteFrance
- Study dates
- 1 Nov 2026to 3 Nov 2028
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years.
- Body mass index (BMI) ≥30 kg/m².
- Referred to the Sleep Medicine Center for routine diagnostic polysomnography because of suspected obstructive sleep apnea.
- Affiliated with a French health insurance scheme.
- Received information about the study and did not object to the use of their data.
- Able to understand the study information and complete study questionnaires.
Who cannot join
- Legal incapacity or inability to provide non-opposition to participation.
- Previous treatment with continuous positive airway pressure (CPAP) or non-invasive ventilation.
- Participation in another interventional clinical study that could interfere with the present study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Croix-Rousse Hospital, Hospices Civils de Lyon
Lyon, 69004
Pierre TANKERE, Dr, 0472071929, Pierre.tankere01@chu-lyon.fr
Virginie INFANTI, Dr
About this study
Official title: Hypercapnic Burden in Adults With Obesity Undergoing Diagnostic Polysomnography for Suspected Obstructive Sleep Apnea: A Prospective Observational Cohort Study
Obesity-related sleep hypoventilation represents a continuum ranging from isolated nocturnal hypoventilation to obesity hypoventilation syndrome. Current diagnostic criteria rely mainly on dichotomous thresholds and may not adequately reflect cumulative nocturnal carbon dioxide exposure.
Hypercapnic burden, defined as the cumulative area under the transcutaneous carbon dioxide (PtcCO₂) curve above a predefined threshold, has recently emerged as a novel physiological marker integrating both the intensity and duration of nocturnal hypercapnia.
Read more
This prospective observational cohort study aims to evaluate the association between nocturnal hypercapnic burden and obstructive sleep apnea severity, assessed by the apnea-hypopnea index (AHI), in adults with obesity referred for diagnostic polysomnography.
Secondary objectives include evaluating associations between hypercapnic burden and sleep architecture, respiratory events, oxygenation parameters, daytime symptoms, and patient-reported outcomes. In addition, the study will investigate the relationship between nocturnal hypercapnic burden and sleep inertia, assessed using the Sleep Inertia Questionnaire (SIQ), based on the hypothesis that greater nocturnal carbon dioxide exposure immediately before awakening may contribute to impaired alertness upon awakening.
Hypothesis: Increased nocturnal hypercapnic burden is associated with greater obstructive sleep apnea severity and reflects an additional physiological dimension of obesity-related sleep hypoventilation beyond conventional polysomnographic indices. Furthermore, higher nocturnal hypercapnic burden is hypothesized to be associated with greater sleep inertia.
- Conditions
- Obstructive Sleep Apnea, Obesity (BMI>30), Obesity Hypoventilation Syndrome (OHS), Sleep Hypoventilation
- Being tested
- Sleep Inertia Questionnaire (SIQ)
- Keywords
- Hypercapnic burden, Transcutaneous carbon dioxide, Polysomnography, Obesity, Sleep apnea, Sleep hypoventilation
- Medical subject headings
- Sleep Apnea, Obstructive, Obesity, Obesity Hypoventilation Syndrome, Sleep Apnea Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sleep Inertia Questionnaire (SIQ)Behavioural
The only research-specific procedure is the completion of the Sleep Inertia Questionnaire (SIQ), a self-administered questionnaire requiring approximately 5 minutes to complete and performed once after the diagnostic sleep study.
| Study group | Role | What they receive |
|---|---|---|
| Adults with obesity referred for diagnostic polysomnography | Experimental | Adults with obesity (body mass index ≥30 kg/m²) referred to the Sleep Medicine Center for routine diagnostic polysomnography because of suspected obstructive sleep apnea Receives: Behavioral: Sleep Inertia Questionnaire (SIQ) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation between nocturnal hypercapnic burden and apnea-hypopnea index
Correlation between nocturnal hypercapnic burden above 45 mmHg (HB45), defined as the area under the nocturnal transcutaneous carbon dioxide pressure (PtcCO₂) curve above 45 mmHg and normalized per hour of recording (mmHg·min/hour), and the apnea-hypopnea index derived from diagnostic polysomnography (events/hour).
The correlation will be assessed using Pearson's or Spearman's correlation coefficient, according to data distribution.
Measured: Baseline only (overnight diagnostic polysomnography)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2026
- Study start1 Nov 2026 (estimated)
- Primary completion3 Nov 2028 (estimated)
- Study completion3 Nov 2028 (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.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Single-centre, prospective, RIPH 3 - research involving human subjects outside of health products
- Masking
- None (open label)
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07809061
- Sponsor's protocol ID
- 69HCL26_0743
- Other IDs
- ID RCB
- Acronym
- HBO-POSA
- Status last verified
- Aug 2026
- First submitted
- 11 Aug 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hypercapnic Burden in Adults With Obesity Undergoing Diagnostic Polysomnography for Suspected Obstructive Sleep Apnea: A Prospective Observational Cohort Study
- ClinicalTrials.gov ID
- NCT07809061
- Acronym / sponsor ID
- HBO-POSA / 69HCL26_0743
- Conditions
- Obstructive Sleep Apnea, Obesity (BMI>30), Obesity Hypoventilation Syndrome (OHS), Sleep Hypoventilation
- Keywords
- Hypercapnic burden, Transcutaneous carbon dioxide, Polysomnography, Obesity, Sleep apnea, Sleep hypoventilation
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 3 Nov 2028 (estimated)
- Study completion
- 3 Nov 2028 (estimated)
- First posted
- 9 Sep 2026 (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.
Obesity-related sleep hypoventilation represents a continuum ranging from isolated nocturnal hypoventilation to obesity hypoventilation syndrome. Current diagnostic criteria rely mainly on dichotomous thresholds and may not adequately reflect cumulative nocturnal carbon dioxide exposure.
Hypercapnic burden, defined as the cumulative area under the transcutaneous carbon dioxide (PtcCO₂) curve above a predefined threshold, has recently emerged as a novel physiological marker integrating both the intensity and duration of nocturnal hypercapnia.
This prospective observational cohort study aims to evaluate the association between nocturnal hypercapnic burden and obstructive sleep apnea severity, assessed by the apnea-hypopnea index (AHI), in adults with obesity referred for diagnostic polysomnography.
Secondary objectives include evaluating associations between hypercapnic burden and sleep architecture, respiratory events, oxygenation parameters, daytime symptoms, and patient-reported outcomes. In addition, the study will investigate the relationship between nocturnal hypercapnic burden and sleep inertia, assessed using the Sleep Inertia Questionnaire (SIQ), based on the hypothesis that greater nocturnal carbon dioxide exposure immediately before awakening may contribute to impaired alertness upon awakening.
Hypothesis: Increased nocturnal hypercapnic burden is associated with greater obstructive sleep apnea severity and reflects an additional physiological dimension of obesity-related sleep hypoventilation beyond conventional polysomnographic indices. Furthermore, higher nocturnal hypercapnic burden is hypothesized to be associated with greater sleep inertia.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Single-centre, prospective, RIPH 3 - research involving human subjects outside of health products
| Arm | Type | Receives |
|---|---|---|
| Adults with obesity referred for diagnostic polysomnography | Experimental | Behavioral: Sleep Inertia Questionnaire (SIQ)Adults with obesity (body mass index ≥30 kg/m²) referred to the Sleep Medicine Center for routine diagnostic polysomnography because of suspected obstructive sleep apnea |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥18 years.
- Body mass index (BMI) ≥30 kg/m².
- Referred to the Sleep Medicine Center for routine diagnostic polysomnography because of suspected obstructive sleep apnea.
- Affiliated with a French health insurance scheme.
- Received information about the study and did not object to the use of their data.
Key exclusion criteria (3 listed)
- Legal incapacity or inability to provide non-opposition to participation.
- Previous treatment with continuous positive airway pressure (CPAP) or non-invasive ventilation.
- Participation in another interventional clinical study that could interfere with the present study.
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 |
|---|---|---|
| Sleep Inertia Questionnaire (SIQ)The only research-specific procedure is the completion of the Sleep Inertia Questionnaire (SIQ), a self-administered questionnaire requiring approximately 5 minutes to complete and performed once after the diagnostic sleep study. | Behavioural | Adults with obesity referred for diagnostic polysomnography |
Primary outcome
Correlation between nocturnal hypercapnic burden and apnea-hypopnea index
Time frame: Baseline only (overnight diagnostic polysomnography)
Correlation between nocturnal hypercapnic burden above 45 mmHg (HB45), defined as the area under the nocturnal transcutaneous carbon dioxide pressure (PtcCO₂) curve above 45 mmHg and normalized per hour of recording (mmHg·min/hour), and the apnea-hypopnea index derived from diagnostic polysomnography (events/hour). The correlation will be assessed using Pearson's or Spearman's correlation coefficient, according to data distribution.
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 9 Sep 2026.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sleep Inertia Questionnaire (SIQ) in people with Obstructive Sleep Apnea and Obesity (BMI>30), run by Hospices Civils de Lyon at 1 site in France.
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 6 inclusion and 3 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 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. 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 Pierre TANKERE, Dr (0472071929, Pierre.tankere01@chu-lyon.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation between nocturnal hypercapnic burden and apnea-hypopnea index (time frame: Baseline only (overnight diagnostic polysomnography)). 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 9 Sep 2026.