Diaphragmatic Function and Respiratory Drive in OSA and COPD

June 24, 2025 updated by: Ning Ding, Nanjing Medical University

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Jiangsu
      • Nanjing, Jiangsu, China, 210029
        • Recruiting
        • The First Affiliated Hospital of Nanjing Medical University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

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.

Description

Inclusion Criteria:

  1. Patients aged between 18 and 80 years.
  2. For OSA Group: Diagnosed obstructive sleep apnea with AHI ≥ 5 events/hour based on overnight polysomnography.
  3. For COPD Group: Diagnosed chronic obstructive pulmonary disease based on GOLD guidelines.
  4. For Overlap Group: Diagnosed both OSA (AHI ≥ 5) and COPD.
  5. For Control Group: Healthy volunteers with no known respiratory diseases or sleep disorders.
  6. Ability and willingness to provide informed consent for participation in the study.

Exclusion Criteria:

  1. Severe cardiovascular diseases (e.g., unstable angina, heart failure NYHA III/IV).
  2. Severe hepatic or renal insufficiency.
  3. Neuromuscular diseases affecting respiratory muscles.
  4. Recent upper airway or thoracic surgery (within 3 months).
  5. Pregnancy or breastfeeding.
  6. Participants who cannot complete assessments due to cognitive impairment or poor cooperation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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.
Other: Diaphragmatic Ultrasound and EMG Assessment
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.
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.
Other: Diaphragmatic Ultrasound and EMG Assessment
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.
COPD Group
Patients diagnosed with chronic obstructive pulmonary disease (COPD) based on GOLD guidelines, assessed for diaphragmatic morphofunction and respiratory drive.
Other: Diaphragmatic Ultrasound and EMG Assessment
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.
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.
Other: Diaphragmatic Ultrasound and EMG Assessment
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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
Baseline (at enrollment)
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.
Baseline (at enrollment)
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.
Baseline (at enrollment)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Diaphragmatic excursion measured by ultrasound during deep breathing
Time Frame: Baseline (at enrollment)
To evaluate diaphragmatic mobility (cm) during deep breathing using standardized ultrasound protocols.
Baseline (at enrollment)
Respiratory impedance parameter R5
Time Frame: Baseline (at enrollment)
To compare small airway resistance (kPa·s·L-¹) between groups using impulse oscillometry.
Baseline (at enrollment)
Respiratory resistance at 20 Hz (R20)
Time Frame: Baseline (at enrollment)
To compare central airway resistance (kPa·s·L-¹) using impulse oscillometry.
Baseline (at enrollment)
Difference in resistance (R5-R20)
Time Frame: Baseline (at enrollment)
To evaluate small airway dysfunction by calculating the difference between R5 and R20 (kPa·s·L-¹) .
Baseline (at enrollment)
Forced expiratory volume in 1 second (FEV1)
Time Frame: Baseline (at enrollment)
To compare FEV1 (L) across groups and assess its relationship with diaphragmatic function.
Baseline (at enrollment)
Forced vital capacity (FVC)
Time Frame: Baseline (at enrollment)
To compare FVC (L) across groups and assess pulmonary capacity.
Baseline (at enrollment)
FEV1/FVC ratio
Time Frame: Baseline (at enrollment)
To evaluate airflow obstruction using the FEV1/FVC ratio (%).
Baseline (at enrollment)
Apnea-hypopnea index (AHI)
Time Frame: Baseline (at enrollment)
To evaluate sleep-disordered breathing severity (events/hour) in OSA and Overlap groups.
Baseline (at enrollment)
Oxygen desaturation index (ODI)
Time Frame: Baseline (at enrollment)
To assess oxygen desaturation frequency during sleep (events/hour) using PSG data.
Baseline (at enrollment)
Minimum oxygen saturation (SpO₂ min)
Time Frame: Baseline (at enrollment)
To capture the lowest oxygen saturation (%) during overnight monitoring.
Baseline (at enrollment)
Time below 90% oxygen saturation (T90)
Time Frame: Baseline (at enrollment)
To calculate the percentage of sleep time with oxygen saturation < 90% (%).
Baseline (at enrollment)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Nanjing Medical University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 31, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 15, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 25, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 4, 2025

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 25, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 24, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2021-SR-347

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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