Clinical trial NCT07003399: Diaphragmatic Function and Respiratory Drive in OSA and COPD
Official title: Diaphragmatic Morphofunction and Respiratory Drive in OSA and COPD: Insights From Ultrasound and EMG-based Cross-Sectional Analysis
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Obstructive Sleep Apnea
Keywords: Obstructive Sleep Apnea
Chronic Obstructive Pulmonary Disease
Overlap Syndrome
Lead sponsor: Nanjing Medical University
Sponsor class: OTHER
First posted: 2025-06-04
Enrollment: 83
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
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.

Brief 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. 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Diaphragmatic electromyography (EMGdi-rest) at baseline
timeFrame: Baseline (at enrollment)
measure: Diaphragmatic EMG during maximal inspiration (EMGdi-max)
timeFrame: Baseline (at enrollment)
measure: Relative inspiratory EMG effort (EMGdi%max)
timeFrame: Baseline (at enrollment)
Secondary outcomes:
measure: Diaphragmatic excursion measured by ultrasound during deep breathing
timeFrame: Baseline (at enrollment)
measure: Respiratory impedance parameter R5
timeFrame: Baseline (at enrollment)
measure: Respiratory resistance at 20 Hz (R20)
timeFrame: Baseline (at enrollment)
measure: Difference in resistance (R5-R20)
timeFrame: Baseline (at enrollment)
measure: Forced expiratory volume in 1 second (FEV1)
timeFrame: Baseline (at enrollment)
measure: Forced vital capacity (FVC)
timeFrame: Baseline (at enrollment)
measure: FEV1/FVC ratio
timeFrame: Baseline (at enrollment)
measure: Apnea-hypopnea index (AHI)
timeFrame: Baseline (at enrollment)
measure: Oxygen desaturation index (ODI)
timeFrame: Baseline (at enrollment)
measure: Minimum oxygen saturation (SpO₂ min)
timeFrame: Baseline (at enrollment)
measure: Time below 90% oxygen saturation (T90)
timeFrame: Baseline (at enrollment)
Other outcomes:
Locations:
city: Nanjing
country: China
facility: The First Affiliated Hospital of Nanjing Medical University
state: Jiangsu
Study officials:
References:
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citation: 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.
citation: 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.
citation: 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.