ObservationNCT03051815
Influence of Craniofacial Restriction on Rebound of Obstructive Sleep Apnea Following Weight Gain
An observational study of Observation, run by Chinese University of Hong Kong at 1 site in China.
Trial summary
Apart from obesity, craniofacial factors are well recognized in the pathogenesis of obstructive sleep apnea (OSA) and are likely to play an important role in influencing the response to weight loss. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Observation
- How many people
- 20 participants
- Where
- 1 siteChina
- Study dates
- 1 Sep 2017to 1 Sep 2018
- Phase
- Observational
- Are there results?
- None posted in the registry
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
- Adult, Older adult
Study population: Subjects are participants in a previously described dietician-based weight loss study in obese Chinese with obstructive sleep apnea (OSA) in which 61 subjects underwent a 12-month weight loss program consisting of dietician consultation with caloric reduction of 10% to 20% in daily energy intake from the patient's usual diet and then the goal was adjusted subsequently based on changes in body weight with target BMI toward 23 kg/m2 om the uear pf 2010-2013. Specific study entry criteria included an age range between 30 and 80 years, body mass index (BMI) >25 kg/m2, and moderate to severe OSA (apnea-hypopnea index (AHI) >15/hr) before the weight loss program performed in the year of 2010-2013. All subjects from the intervention group will be invited to participate.
Who may be able to join
- Subjects are participants in a previously described dietician-based weight loss study in obese Chinese with obstructive sleep apnea (OSA). Specific study entry criteria included an age range between 30 and 80 years, body mass index (BMI) >25 kg/m2, and moderate to severe OSA (apnea-hypopnea index (AHI) >15 events/hour) before the weight loss program performed in the year of 2010-2013.
Who cannot join
- Subjects refused to participate the trial or unable to consent.
Trial locations and contacts
1 site in 1 country.
About this study
Apart from obesity, craniofacial factors are well recognized in the pathogenesis of obstructive sleep apnea (OSA) and are likely to play an important role in influencing the response to weight loss. The prevalence of OSA syndrome is as common among the middle-aged Hong Kong Chinese populations as the Caucasians, despite our Chinese patients having much lower body mass index (BMI). From previous work on ethnic comparison, for the same degree of OSA severity, Caucasians were more overweight, whereas Chinese exhibited more craniofacial bony restriction. Cephalometric measurements based on lateral radiograph of the upper airway have shown that a shorter distance between maxillary projection from the cranial base, a smaller posterior airway space, less mandibular protrusion, a narrower space between the hard palate and cranial base, and a more caudally placed hyoid bone predispose to a higher apnea-hypopnea index (AHI). A recent study shown that a shorter mandibular length as measured by lateral cephalometry was associated with a greater fall in AHI after weight loss. Another study using craniofacial computed tomography (CT) scans to evaluate the maxillomandibular bony volume found that craniofacial restriction influenced the relationship between weight loss and OSA improvement. Collectively, these studies suggest that the effect on AHI with weight loss is likely to be more pronounced in those with a smaller craniofacial skeleton. However, the effect of the craniofacial restriction on the degree of rebound in OSA following weight gain after the weight loss intervention is unknown.
The study aims to investigate the change in weight and OSA severity following cessation of a lifestyle modification program (LMP) and examine the relationship between craniofacial restriction and the degree of OSA reoccurrence.
Read the detailed description
All subjects will be advised to stop using continuous positive airway pressure (CPAP) for at least 7 days as previous study showed that severity of obstructive sleep apnea (OSA) did not increase further after the first week of CPAP withdrawal. Subjects will then be invited to undergo a limited sleep study using "EMBLETTA" portable diagnostic system (MEDCARE, Iceland). The EMBLETTA is a pocket-sized digital recording device. It is a multi-channel transducer, providing an apnea-hypopnea index (AHI) based on recording time. It also detects both respiratory and abdominal efforts through the effort sensor and can differentiate between obstructive and central events. Built-in position sensors are also available to differentiate supine from non-supine events. Respiratory events are scored when desaturations of at least 4% occurred in the absence of moving artefacts and irrespective of co-existing changes in snoring or heart rate. The EMBLETTA operates on battery power, with the internal memory storage of 16 MB, which allows approximately 12 hours of data collection. The EMBLETTA default settings for apneas and hypopneas will be used in this study. An apnea is defined as a decrease in airflow by 80% of baseline for at least 10 seconds. The EMBLETTA default maximum apnea duration is set at 80 seconds. A hypopnea is defined as a decrease in airflow by 50% of baseline for at least 10 seconds. The EMBLETTA default maximum hypopnea duration is set at 100 seconds. The EMBLETTA AHI used for analysis is automatically analysed by the EMBLETTA software. The EMBLETTA device has been validated against hospital-based polysomnography in the Hong Kong Chinese population. The EMBLETTA is a highly sensitive and specific screening device in quantifying AHI and differentiating obstructing and supine events when compared against polysomnography (PSG) in patients with suspected OSA. Patients will be instructed how to operate the EMBLETTA device for the sleep recording and estimate their time of sleep. Those who have failed the EMBLETTA sleep study will be arranged to have a second home EMBLETTA sleep study. Patients who are symptomatic of OSA with a negative home EMBLETTA sleep study will be arranged to have a hospital-based PSG.
All subjects will undergo three-dimensional (3D) computed tomography (CT) scans of the head/neck region to evaluate the upper airway and craniofacial structures. Craniofacial restriction is determined by measuring the size of the maxillomandibular volume based on the mandibular cephalometric landmarks (left and right condylion, left and right gonion, anterior nasal spine (ANS) and menton) as per previous published study. The patient is positioned in the natural head position with a closed lip and bite. All measurements will be made by a single assessor and the analysis will be performed blind to knowledge of weight loss and AHI data.
All subjects will go through several measurements. These include assessment of subjective sleepiness with the Epworth Sleepiness scale (ESS), anthropometric measurements (body mass index, neck and waist circumference) and blood pressure.
The ESS is a questionnaire specific to symptoms of daytime sleepiness and the patients are asked to score the likelihood of falling asleep in eight different situations with different levels of stimulation, adding up to a total score of 0 to 24.
- Conditions
- Observation
- Keywords
- obstructive sleep apnea
- Medical subject headings
- Sleep Apnea, Obstructive
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in apnea-hypopnea index (AHI)
Measured: 7 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Feb 2017
- Study start1 Sep 2017
- Primary completion1 Sep 2018
- Study completion1 Sep 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObservationStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe 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
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Susanna SS Ng, Chinese University of Hong Kong
- Investigators
- Susanna So-Shan Ng, MBChB, Principal investigator, Hospital Authority
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03051815
- Sponsor's protocol ID
- OSA-MMV/Ng/2016
- Status last verified
- Feb 2019
- First submitted
- 3 Feb 2017
- Last updated
- 4 Feb 2019
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Feb 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence of Craniofacial Restriction on Rebound of Obstructive Sleep Apnea Following Weight Gain
- ClinicalTrials.gov ID
- NCT03051815
- Acronym / sponsor ID
- OSA-MMV/Ng/2016
- Conditions
- Observation
- Keywords
- obstructive sleep apnea
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 1 Sep 2017 (actual)
- Primary completion
- 1 Sep 2018 (actual)
- Study completion
- 1 Sep 2018 (actual)
- First posted
- 14 Feb 2017 (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.
Apart from obesity, craniofacial factors are well recognized in the pathogenesis of obstructive sleep apnea (OSA) and are likely to play an important role in influencing the response to weight loss. The prevalence of OSA syndrome is as common among the middle-aged Hong Kong Chinese populations as the Caucasians, despite our Chinese patients having much lower body mass index (BMI). From previous work on ethnic comparison, for the same degree of OSA severity, Caucasians were more overweight, whereas Chinese exhibited more craniofacial bony restriction. Cephalometric measurements based on lateral radiograph of the upper airway have shown that a shorter distance between maxillary projection from the cranial base, a smaller posterior airway space, less mandibular protrusion, a narrower space between the hard palate and cranial base, and a more caudally placed hyoid bone predispose to a higher apnea-hypopnea index (AHI). A recent study shown that a shorter mandibular length as measured by lateral cephalometry was associated with a greater fall in AHI after weight loss. Another study using craniofacial computed tomography (CT) scans to evaluate the maxillomandibular bony volume found that craniofacial restriction influenced the relationship between weight loss and OSA improvement. Collectively, these studies suggest that the effect on AHI with weight loss is likely to be more pronounced in those with a smaller craniofacial skeleton. However, the effect of the craniofacial restriction on the degree of rebound in OSA following weight gain after the weight loss intervention is unknown.
The study aims to investigate the change in weight and OSA severity following cessation of a lifestyle modification program (LMP) and examine the relationship between craniofacial restriction and the degree of OSA reoccurrence.
Detailed description
All subjects will be advised to stop using continuous positive airway pressure (CPAP) for at least 7 days as previous study showed that severity of obstructive sleep apnea (OSA) did not increase further after the first week of CPAP withdrawal. Subjects will then be invited to undergo a limited sleep study using "EMBLETTA" portable diagnostic system (MEDCARE, Iceland). The EMBLETTA is a pocket-sized digital recording device. It is a multi-channel transducer, providing an apnea-hypopnea index (AHI) based on recording time. It also detects both respiratory and abdominal efforts through the effort sensor and can differentiate between obstructive and central events. Built-in position sensors are also available to differentiate supine from non-supine events. Respiratory events are scored when desaturations of at least 4% occurred in the absence of moving artefacts and irrespective of co-existing changes in snoring or heart rate. The EMBLETTA operates on battery power, with the internal memory storage of 16 MB, which allows approximately 12 hours of data collection. The EMBLETTA default settings for apneas and hypopneas will be used in this study. An apnea is defined as a decrease in airflow by 80% of baseline for at least 10 seconds. The EMBLETTA default maximum apnea duration is set at 80 seconds. A hypopnea is defined as a decrease in airflow by 50% of baseline for at least 10 seconds. The EMBLETTA default maximum hypopnea duration is set at 100 seconds. The EMBLETTA AHI used for analysis is automatically analysed by the EMBLETTA software. The EMBLETTA device has been validated against hospital-based polysomnography in the Hong Kong Chinese population. The EMBLETTA is a highly sensitive and specific screening device in quantifying AHI and differentiating obstructing and supine events when compared against polysomnography (PSG) in patients with suspected OSA. Patients will be instructed how to operate the EMBLETTA device for the sleep recording and estimate their time of sleep. Those who have failed the EMBLETTA sleep study will be arranged to have a second home EMBLETTA sleep study. Patients who are symptomatic of OSA with a negative home EMBLETTA sleep study will be arranged to have a hospital-based PSG.
All subjects will undergo three-dimensional (3D) computed tomography (CT) scans of the head/neck region to evaluate the upper airway and craniofacial structures. Craniofacial restriction is determined by measuring the size of the maxillomandibular volume based on the mandibular cephalometric landmarks (left and right condylion, left and right gonion, anterior nasal spine (ANS) and menton) as per previous published study. The patient is positioned in the natural head position with a closed lip and bite. All measurements will be made by a single assessor and the analysis will be performed blind to knowledge of weight loss and AHI data.
All subjects will go through several measurements. These include assessment of subjective sleepiness with the Epworth Sleepiness scale (ESS), anthropometric measurements (body mass index, neck and waist circumference) and blood pressure.
The ESS is a questionnaire specific to symptoms of daytime sleepiness and the patients are asked to score the likelihood of falling asleep in eight different situations with different levels of stimulation, adding up to a total score of 0 to 24.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Subjects are participants in a previously described dietician-based weight loss study in obese Chinese with obstructive sleep apnea (OSA) in which 61 subjects underwent a 12-month weight loss program consisting of dietician consultation with caloric reduction of 10% to 20% in daily energy intake from the patient's usual diet and then the goal was adjusted subsequently based on changes in body weight with target BMI toward 23 kg/m2 om the uear pf 2010-2013. Specific study entry criteria included an age range between 30 and 80 years, body mass index (BMI) >25 kg/m2, and moderate to severe OSA (apnea-hypopnea index (AHI) >15/hr) before the weight loss program performed in the year of 2010-2013. All subjects from the intervention group will be invited to participate.
Key inclusion criteria (1 listed)
- Subjects are participants in a previously described dietician-based weight loss study in obese Chinese with obstructive sleep apnea (OSA). Specific study entry criteria included an age range between 30 and 80 years, body mass index (BMI) >25 kg/m2, and moderate to severe OSA (apnea-hypopnea index (AHI) >15 events/hour) before the weight loss program performed in the year of 2010-2013.
Key exclusion criteria (1 listed)
- Subjects refused to participate the trial or unable to consent.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in apnea-hypopnea index (AHI)
Time frame: 7 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Feb 2019.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Susanna So-Shan Ng, MBChB principal investigator
Hospital Authority
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Observation, run by Chinese University of Hong Kong at 1 site in China.
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 1 inclusion and 1 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: finished, as of the sponsor's last update on 4 Feb 2019. 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 China. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in apnea-hypopnea index (AHI) (time frame: 7 years). 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 4 Feb 2019.