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Recruiting NCT07003399

Diaphragmatic Function and Respiratory Drive in OSA and COPD

— Observational Obstructive Sleep Apnea

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Diaphragmatic Ultrasound and EMG Assessment.
Who it may be relevant to
Registry conditions: Obstructive Sleep Apnea. Basic parameters: 18 years — 80 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
China
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Official title

Diaphragmatic Morphofunction and Respiratory Drive in OSA and COPD: Insights From Ultrasound and EMG-based Cross-Sectional Analysis

Overview

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.

Interventions

  • 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.

Primary outcome measures

  • Diaphragmatic electromyography (EMGdi-rest) at baseline [Time frame: Baseline (at enrollment)]
  • Diaphragmatic EMG during maximal inspiration (EMGdi-max) [Time frame: Baseline (at enrollment)]
  • Relative inspiratory EMG effort (EMGdi%max) [Time frame: Baseline (at enrollment)]
Secondary outcome measures (11)
  • 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)]

Eligibility criteria

Inclusion criteria

  • 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.

Exclusion criteria

  • 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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model
Cohort

Study locations

China · 1 center
  • The First Affiliated Hospital of Nanjing Medical University — Nanjing

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. PMID 35034195
  • Jolley 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. PMID 26312873
  • He 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. PMID 27807016
  • Zhang 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. PMID 32836084
  • Ramsook 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. PMID 26795460
  • James 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. PMID 35861594

Identifiers

NCT: NCT07003399 · 2021-SR-347

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗