Obstructive Sleep ApneaNCT07003399
Diaphragmatic Function and Respiratory Drive in OSA and COPD
An observational study of Obstructive Sleep Apnea, run by Nanjing Medical University at 1 site in China.
Trial summary
This cross-sectional observational study aims to assess the diaphragmatic morphofunction and respiratory drive characteristics among patients with obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), overlap syndrome (OS), and healthy controls. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Obstructive Sleep Apnea
- What is being tested?
- Diaphragmatic Ultrasound and EMG Assessment
- How many people
- 80 participants
- Where
- 1 siteChina
- Study dates
- 1 Jan 2025to 31 Aug 2025
- Phase
- Observational
- 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 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients diagnosed with obstructive sleep apnea, chronic obstructive pulmonary disease, overlap syndrome (OSA and COPD), and healthy volunteers from a single center. Subjects will be evaluated for diaphragmatic morphofunction and respiratory drive using ultrasound and EMG.
Who may be able to join
- Patients aged between 18 and 80 years.
- For OSA Group: Diagnosed obstructive sleep apnea with AHI ≥ 5 events/hour based on overnight polysomnography.
- For COPD Group: Diagnosed chronic obstructive pulmonary disease based on GOLD guidelines.
- For Overlap Group: Diagnosed both OSA (AHI ≥ 5) and COPD.
- For Control Group: Healthy volunteers with no known respiratory diseases or sleep disorders.
- Ability and willingness to provide informed consent for participation in the study.
Who cannot join
- Severe cardiovascular diseases (e.g., unstable angina, heart failure NYHA III/IV).
- Severe hepatic or renal insufficiency.
- Neuromuscular diseases affecting respiratory muscles.
- Recent upper airway or thoracic surgery (within 3 months).
- Pregnancy or breastfeeding.
- Participants who cannot complete assessments due to cognitive impairment or poor cooperation.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
The First Affiliated Hospital of Nanjing Medical University
Nanjing, Jiangsu, 210029
Ding Ning, doctor, 86-25-68136723, dr.ningding@live.cn
About this study
Official title: Diaphragmatic Morphofunction and Respiratory Drive in OSA and COPD: Insights From Ultrasound and EMG-based Cross-Sectional Analysis
This cross-sectional observational study aims to assess the diaphragmatic morphofunction and respiratory drive characteristics among patients with obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), overlap syndrome (OS), and healthy controls. Using ultrasound imaging and surface diaphragm electromyography (EMGdi), the study will explore group differences in diaphragmatic morphology, function, and respiratory drive indicators, and evaluate their clinical significance in disease differentiation and severity assessment.
Read the detailed description
This is a single-center cross-sectional study designed to compare the diaphragmatic morphofunction and respiratory drive among four groups: OSA, COPD, overlap syndrome (patients with both OSA and COPD), and healthy controls. Participants will undergo overnight polysomnography (PSG), spirometry, impulse oscillometry, and diaphragm ultrasound combined with surface EMGdi measurements. The study will analyze group differences in diaphragmatic thickness, excursion, thickening fraction, and EMGdi parameters including EMGdi-rest, EMGdi-max, and EMGdi%max. The relationships between diaphragmatic indicators and respiratory parameters (FEV1, FVC, AHI, R5-R20, etc.) will also be assessed. This study aims to provide objective evidence for diaphragmatic dysfunction characterization in OSA and COPD, as well as to explore its diagnostic utility in overlap syndrome.
- Conditions
- Obstructive Sleep Apnea
- Being tested
- Diaphragmatic Ultrasound and EMG Assessment
- Keywords
- Obstructive Sleep Apnea, Chronic Obstructive Pulmonary Disease, Overlap Syndrome
- Medical subject headings
- Sleep Apnea, Obstructive, Pulmonary Disease, Chronic Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diaphragmatic Ultrasound and EMG AssessmentOther
Non-invasive assessment of diaphragmatic morphofunction and respiratory drive using ultrasound imaging and diaphragm electromyography (EMG). This evaluation will be performed once per participant without any therapeutic intervention.
| Study group | Role | What they receive |
|---|---|---|
| Normal Group | Healthy subjects with no known respiratory diseases or sleep disorders, serving as the control group for baseline comparison of diaphragmatic function and respiratory drive. Receives: Other: Diaphragmatic Ultrasound and EMG Assessment | |
| OSA Group | Patients diagnosed with obstructive sleep apnea (OSA) based on polysomnography criteria (AHI ≥ 5 events/hour), evaluated for diaphragmatic function and respiratory drive using ultrasound and EMG. Receives: Other: Diaphragmatic Ultrasound and EMG Assessment | |
| COPD Group | Patients diagnosed with chronic obstructive pulmonary disease (COPD) based on GOLD guidelines, assessed for diaphragmatic morphofunction and respiratory drive. Receives: Other: Diaphragmatic Ultrasound and EMG Assessment | |
| Overlap Group | Patients with overlap syndrome (coexisting OSA and COPD), evaluated for diaphragmatic function and respiratory drive using ultrasound and EMG to explore combined disease impact. Receives: Other: Diaphragmatic Ultrasound and EMG Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Diaphragmatic electromyography (EMGdi-rest) at baseline
To assess resting diaphragmatic electromyographic activity (µV) across OSA, COPD, Overlap, and control groups using surface and esophageal EMG.
Measured: Baseline (at enrollment)
Diaphragmatic EMG during maximal inspiration (EMGdi-max)
To assess maximal inspiratory diaphragmatic EMG activity (µV) using voluntary effort tests with surface and esophageal EMG.
Measured: Baseline (at enrollment)
Relative inspiratory EMG effort (EMGdi%max)
To calculate the ratio of EMGdi-rest to EMGdi-max as a percentage, reflecting the relative inspiratory effort.
Measured: Baseline (at enrollment)
Secondary outcomes (11)
Diaphragmatic excursion measured by ultrasound during deep breathing
To evaluate diaphragmatic mobility (cm) during deep breathing using standardized ultrasound protocols.
Measured: Baseline (at enrollment)
Respiratory impedance parameter R5
To compare small airway resistance (kPa·s·L-¹) between groups using impulse oscillometry.
Measured: Baseline (at enrollment)
Respiratory resistance at 20 Hz (R20)
To compare central airway resistance (kPa·s·L-¹) using impulse oscillometry.
Measured: Baseline (at enrollment)
Difference in resistance (R5-R20)
To evaluate small airway dysfunction by calculating the difference between R5 and R20 (kPa·s·L-¹) .
Measured: Baseline (at enrollment)
Forced expiratory volume in 1 second (FEV1)
To compare FEV1 (L) across groups and assess its relationship with diaphragmatic function.
Measured: Baseline (at enrollment)
Forced vital capacity (FVC)
To compare FVC (L) across groups and assess pulmonary capacity.
Measured: Baseline (at enrollment)
FEV1/FVC ratio
To evaluate airflow obstruction using the FEV1/FVC ratio (%).
Measured: Baseline (at enrollment)
Apnea-hypopnea index (AHI)
To evaluate sleep-disordered breathing severity (events/hour) in OSA and Overlap groups.
Measured: Baseline (at enrollment)
Oxygen desaturation index (ODI)
To assess oxygen desaturation frequency during sleep (events/hour) using PSG data.
Measured: Baseline (at enrollment)
Minimum oxygen saturation (SpO₂ min)
To capture the lowest oxygen saturation (%) during overnight monitoring.
Measured: Baseline (at enrollment)
Time below 90% oxygen saturation (T90)
To calculate the percentage of sleep time with oxygen saturation < 90% (%).
Measured: Baseline (at enrollment)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2025
- Study start1 Jan 2025
- Primary completion31 Aug 2025 (estimated)
- Study completion31 Aug 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nanjing Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ning Ding, Nanjing Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07003399
- Sponsor's protocol ID
- 2021-SR-347
- Status last verified
- Jun 2025
- First submitted
- 15 May 2025
- Last updated
- 25 Jun 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The individual participant data will not be shared. The informed consent will be ansigned before enrolled in the study and ensured to keep personal information confidential.
Publications
Domnik NJ, Phillips DB, James MD, Ayoo GA, Taylor SM, Scheeren RE, Di Luch AT, Milne KM, Vincent SG, Elbehairy AF, Crinion SJ, Driver HS, Neder JA, O'Donnell DE. Compensatory responses to increased mechanical abnormalities in COPD during sleep. Eur J Appl Physiol. 2022 Mar;122(3):663-676. doi: 10.1007/s00421-021-04869-0. Epub 2022 Jan 16.
PubMed 35034195Jolley C, Luo Y, Steier J, Sylvester K, Man W, Rafferty G, Polkey M, Moxham J. Neural respiratory drive and symptoms that limit exercise in chronic obstructive pulmonary disease. Lancet. 2015 Feb 26;385 Suppl 1:S51. doi: 10.1016/S0140-6736(15)60366-X.
PubMed 26312873He BT, Lu G, Xiao SC, Chen R, Steier J, Moxham J, Polkey MI, Luo YM. Coexistence of OSA may compensate for sleep related reduction in neural respiratory drive in patients with COPD. Thorax. 2017 Mar;72(3):256-262. doi: 10.1136/thoraxjnl-2016-208467. Epub 2016 Nov 2.
PubMed 27807016Zhang N, Luo Y, Yang L, Liu Z, Qiu Z, Huang Q, Zhang Y. Novel method for evaluating the upper airway resistance using the ratio of neural respiratory drive to flow in OSA. Sleep Med. 2020 Sep;73:162-169. doi: 10.1016/j.sleep.2020.05.006. Epub 2020 May 15.
PubMed 32836084Ramsook AH, Koo R, Molgat-Seon Y, Dominelli PB, Syed N, Ryerson CJ, Sheel AW, Guenette JA. Diaphragm Recruitment Increases during a Bout of Targeted Inspiratory Muscle Training. Med Sci Sports Exerc. 2016 Jun;48(6):1179-86. doi: 10.1249/MSS.0000000000000881.
PubMed 26795460James MD, Phillips DB, Vincent SG, Abdallah SJ, Donovan AA, de-Torres JP, Neder JA, Smith BM, Jensen D, O'Donnell DE; Canadian Respiratory Research Network. Exertional dyspnoea in patients with mild-to-severe chronic obstructive pulmonary disease: neuromechanical mechanisms. J Physiol. 2022 Sep;600(18):4227-4245. doi: 10.1113/JP283252. Epub 2022 Aug 5.
PubMed 35861594
Study at a glance
From the registry record, last updated by the sponsor on 25 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diaphragmatic Morphofunction and Respiratory Drive in OSA and COPD: Insights From Ultrasound and EMG-based Cross-Sectional Analysis
- ClinicalTrials.gov ID
- NCT07003399
- Acronym / sponsor ID
- 2021-SR-347
- Conditions
- Obstructive Sleep Apnea
- Keywords
- Obstructive Sleep Apnea, Chronic Obstructive Pulmonary Disease, Overlap Syndrome
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Nanjing Medical UniversityUniversity, hospital or other
- Study start
- 1 Jan 2025 (actual)
- Primary completion
- 31 Aug 2025 (estimated)
- Study completion
- 31 Aug 2025 (estimated)
- First posted
- 4 Jun 2025 (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.
This cross-sectional observational study aims to assess the diaphragmatic morphofunction and respiratory drive characteristics among patients with obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), overlap syndrome (OS), and healthy controls. Using ultrasound imaging and surface diaphragm electromyography (EMGdi), the study will explore group differences in diaphragmatic morphology, function, and respiratory drive indicators, and evaluate their clinical significance in disease differentiation and severity assessment.
Detailed description
This is a single-center cross-sectional study designed to compare the diaphragmatic morphofunction and respiratory drive among four groups: OSA, COPD, overlap syndrome (patients with both OSA and COPD), and healthy controls. Participants will undergo overnight polysomnography (PSG), spirometry, impulse oscillometry, and diaphragm ultrasound combined with surface EMGdi measurements. The study will analyze group differences in diaphragmatic thickness, excursion, thickening fraction, and EMGdi parameters including EMGdi-rest, EMGdi-max, and EMGdi%max. The relationships between diaphragmatic indicators and respiratory parameters (FEV1, FVC, AHI, R5-R20, etc.) will also be assessed. This study aims to provide objective evidence for diaphragmatic dysfunction characterization in OSA and COPD, as well as to explore its diagnostic utility in overlap syndrome.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Normal Group | – | Other: Diaphragmatic Ultrasound and EMG AssessmentHealthy subjects with no known respiratory diseases or sleep disorders, serving as the control group for baseline comparison of diaphragmatic function and respiratory drive. |
| OSA Group | – | Other: Diaphragmatic Ultrasound and EMG AssessmentPatients diagnosed with obstructive sleep apnea (OSA) based on polysomnography criteria (AHI ≥ 5 events/hour), evaluated for diaphragmatic function and respiratory drive using ultrasound and EMG. |
| COPD Group | – | Other: Diaphragmatic Ultrasound and EMG AssessmentPatients diagnosed with chronic obstructive pulmonary disease (COPD) based on GOLD guidelines, assessed for diaphragmatic morphofunction and respiratory drive. |
| Overlap Group | – | Other: Diaphragmatic Ultrasound and EMG AssessmentPatients with overlap syndrome (coexisting OSA and COPD), evaluated for diaphragmatic function and respiratory drive using ultrasound and EMG to explore combined disease impact. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients diagnosed with obstructive sleep apnea, chronic obstructive pulmonary disease, overlap syndrome (OSA and COPD), and healthy volunteers from a single center. Subjects will be evaluated for diaphragmatic morphofunction and respiratory drive using ultrasound and EMG.
Key inclusion criteria (6 listed)
- Patients aged between 18 and 80 years.
- For OSA Group: Diagnosed obstructive sleep apnea with AHI ≥ 5 events/hour based on overnight polysomnography.
- For COPD Group: Diagnosed chronic obstructive pulmonary disease based on GOLD guidelines.
- For Overlap Group: Diagnosed both OSA (AHI ≥ 5) and COPD.
- For Control Group: Healthy volunteers with no known respiratory diseases or sleep disorders.
Key exclusion criteria (6 listed)
- Severe cardiovascular diseases (e.g., unstable angina, heart failure NYHA III/IV).
- Severe hepatic or renal insufficiency.
- Neuromuscular diseases affecting respiratory muscles.
- Recent upper airway or thoracic surgery (within 3 months).
- Pregnancy or breastfeeding.
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 |
|---|---|---|
| Diaphragmatic Ultrasound and EMG AssessmentNon-invasive assessment of diaphragmatic morphofunction and respiratory drive using ultrasound imaging and diaphragm electromyography (EMG). This evaluation will be performed once per participant without any therapeutic intervention. | Other | COPD Group, Normal Group, OSA Group, Overlap Group |
Primary outcome
Diaphragmatic electromyography (EMGdi-rest) at baseline
Time frame: Baseline (at enrollment)
To assess resting diaphragmatic electromyographic activity (µV) across OSA, COPD, Overlap, and control groups using surface and esophageal EMG.
Diaphragmatic EMG during maximal inspiration (EMGdi-max)
Time frame: Baseline (at enrollment)
To assess maximal inspiratory diaphragmatic EMG activity (µV) using voluntary effort tests with surface and esophageal EMG.
Relative inspiratory EMG effort (EMGdi%max)
Time frame: Baseline (at enrollment)
To calculate the ratio of EMGdi-rest to EMGdi-max as a percentage, reflecting the relative inspiratory effort.
11 secondary outcomes
Diaphragmatic excursion measured by ultrasound during deep breathing
Time frame: Baseline (at enrollment)
Respiratory impedance parameter R5
Time frame: Baseline (at enrollment)
Respiratory resistance at 20 Hz (R20)
Time frame: Baseline (at enrollment)
Difference in resistance (R5-R20)
Time frame: Baseline (at enrollment)
Forced expiratory volume in 1 second (FEV1)
Time frame: Baseline (at enrollment)
Forced vital capacity (FVC)
Time frame: Baseline (at enrollment)
FEV1/FVC ratio
Time frame: Baseline (at enrollment)
Apnea-hypopnea index (AHI)
Time frame: Baseline (at enrollment)
Oxygen desaturation index (ODI)
Time frame: Baseline (at enrollment)
Minimum oxygen saturation (SpO₂ min)
Time frame: Baseline (at enrollment)
Time below 90% oxygen saturation (T90)
Time frame: Baseline (at enrollment)
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 25 Jun 2025.
- Background: PubMed 35034195Domnik NJ, Phillips DB, James MD, Ayoo GA, Taylor SM, Scheeren RE, Di Luch AT, Milne KM, Vincent SG, Elbehairy AF, Crinion SJ, Driver HS, Neder JA, O'Donnell DE. Compensatory responses to increased mechanical abnormalities in COPD during sleep. Eur J Appl Physiol. 2022 Mar;122(3):663-676. doi: 10.1007/s00421-021-04869-0. Epub 2022 Jan 16.
- Background: PubMed 26312873Jolley C, Luo Y, Steier J, Sylvester K, Man W, Rafferty G, Polkey M, Moxham J. Neural respiratory drive and symptoms that limit exercise in chronic obstructive pulmonary disease. Lancet. 2015 Feb 26;385 Suppl 1:S51. doi: 10.1016/S0140-6736(15)60366-X.
- Background: PubMed 27807016He BT, Lu G, Xiao SC, Chen R, Steier J, Moxham J, Polkey MI, Luo YM. Coexistence of OSA may compensate for sleep related reduction in neural respiratory drive in patients with COPD. Thorax. 2017 Mar;72(3):256-262. doi: 10.1136/thoraxjnl-2016-208467. Epub 2016 Nov 2.
- Background: PubMed 32836084Zhang N, Luo Y, Yang L, Liu Z, Qiu Z, Huang Q, Zhang Y. Novel method for evaluating the upper airway resistance using the ratio of neural respiratory drive to flow in OSA. Sleep Med. 2020 Sep;73:162-169. doi: 10.1016/j.sleep.2020.05.006. Epub 2020 May 15.
- Background: PubMed 26795460Ramsook AH, Koo R, Molgat-Seon Y, Dominelli PB, Syed N, Ryerson CJ, Sheel AW, Guenette JA. Diaphragm Recruitment Increases during a Bout of Targeted Inspiratory Muscle Training. Med Sci Sports Exerc. 2016 Jun;48(6):1179-86. doi: 10.1249/MSS.0000000000000881.
- Background: PubMed 35861594James MD, Phillips DB, Vincent SG, Abdallah SJ, Donovan AA, de-Torres JP, Neder JA, Smith BM, Jensen D, O'Donnell DE; Canadian Respiratory Research Network. Exertional dyspnoea in patients with mild-to-severe chronic obstructive pulmonary disease: neuromechanical mechanisms. J Physiol. 2022 Sep;600(18):4227-4245. doi: 10.1113/JP283252. Epub 2022 Aug 5.
- Individual participant dataSharing planned: No. The individual participant data will not be shared. The informed consent will be ansigned before enrolled in the study and ensured to keep personal information confidential.
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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?
An observational study of Obstructive Sleep Apnea, run by Nanjing Medical University 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 6 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 25 Jun 2025. 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?
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 Ding Ning, doctor (86-25-68136723, dr.ningding@live.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Diaphragmatic electromyography (EMGdi-rest) at baseline (time frame: Baseline (at enrollment)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07003399, which also lists 6 linked publications.
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 25 Jun 2025.