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Chronic Obstructive Pulmonary Disease (COPD)NCT06827379

Acute Effects of Inspiratory Muscle Training on Peripheral Muscle Metabolism and Autonomic Response in COPD Patients

A study testing IMT-S (strength) and IMT-R (resistance) in people with Chronic Obstructive Pulmonary Disease (COPD), run by Federal University of Paraíba at 1 site in Brazil.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts
Official record
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Trial summary

The study will evaluate the acute effects of inspiratory muscle training (IMT) on peripheral muscle metabolism and autonomic response in patients with chronic obstructive pulmonary disease (COPD). Read more about this study

Who is it for?
Ages 40 to 75 years
What is being tested?
IMT-S (strength) and IMT-R (resistance)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
30 participants
Where
1 siteBrazil
Study dates
1 Mar 2025to 30 Dec 2025
Phase
Interventional
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 40 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patients with COPD according to the Global Initiative for COPD (GOLD, 2023);
  • Aged 40 years or older and under 75 years;
  • Providing both oral and written informed consent.

Who cannot join

  • Inability to perform the IMT protocol and/or functional tests;
  • Presence of psychiatric disorders or cognitive impairments, progressive neurological disorders, cancer, or chronic pain;
  • Cognitive impairment or inability to understand commands.
  • Patients who have experienced any health issue or had a COPD exacerbation in the previous month will also be excluded to ensure that the patient's symptoms are stable.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Brazil1 site
  • Universidade Federal da Paraíba

    João Pessoa, Paraíba, 58051-900

Other trials in Brazil

About this study

Official title: Acute Effects of Inspiratory Muscle Training With Different Loads on Peripheral Muscle Metabolism and Autonomic Response in COPD Patients: A Randomized Crossover Trial

The study will evaluate the acute effects of inspiratory muscle training (IMT) on peripheral muscle metabolism and autonomic response in patients with chronic obstructive pulmonary disease (COPD). This is a randomized, crossover study, with blinding of the evaluator and the researcher responsible for the statistical analysis. Participants will be divided into three groups at different times: TMI- strength (F), TMI to gain inspiratory muscle strength; IMT- resistance (R), IMT for improving inspiratory muscle resistance; and TMI sham. All participants randomized in the study will participate in the three groups, with a minimum interval of 48 hours between participation in each group. Randomization will determine the sequence of participation in the three groups for all participants.

For statistical analysis, an intention-to-treat approach will be used, and the groups will be compared using the Student's t test for continuous variables or the chi-square test for categorical variables. A split-plot ANOVA with repeated measures will be used for primary outcomes, and analysis of covariance will be conducted to identify differences between groups using baseline scores as covariates. Effect sizes and confidence intervals will be calculated using eta squared.

It is expected that IMT applied at different loads can promote effects on vascular function, peripheral muscle metabolism and the response of the autonomic nervous system in patients with COPD, which can greatly contribute to the understanding of the physiological effects of this therapy and support its prescription. as a therapeutic intervention in the rehabilitation of patients with pulmonary diseases.

Being tested
IMT-S (strength), IMT-R (resistance), Sham - IMT
Keywords
COPD, Exercise, Performance, Lung diseases.
Medical subject headings
Pulmonary Disease, Chronic Obstructive, Motor Activity, Lung Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • IMT-S (strength)Other

    Composed of 3 sets of 1 minute of maximum, deep inspirations, with 2 minutes of rest between sets, totaling 3 minutes of IMT. The initial load will be individualized according to the MIP, with the load equivalent to 60% of the MIP.

  • IMT-R (resistance)Other

    Composed of 3 sets of 2 minutes of maximum, deep inspirations, with 2 minutes of rest between sets, totaling 6 minutes of IMT. The load will also be individualized according to the MIP, with the load equivalent to 30% of the MIP.

  • Sham - IMTOther

    Composed of 3 sets of 2 minutes of maximum, deep inspirations, with 2 minutes of rest between sets, totaling 6 minutes of IMT with a minimum load of 3cmH2O.

Study groups in NCT06827379
Study groupRoleWhat they receive
IMT-S (strength)ExperimentalWill be individualized according to the MIP achieved in the initial assessment of each patient's inspiratory muscle strength, with the load being equivalent to 60% of the MIP in cmH2O.
Receives: Other: IMT-S (strength)
IMT-R (resistance)ExperimentalThree sets of two minutes of maximum, deep inspirations followed by two minutes of rest between them, totaling six minutes of IMT. The initial load of the equipment for the IMT-R group will also be individualized, equivalent to 30% of the MIP in cmH2O.
Receives: Other: IMT-R (resistance)
ShamSham comparatorThree sets of two minutes of maximum, deep inspirations followed by two minutes of rest between them, totaling six minutes of IMT with a minimum load of 3cmH2O.
Receives: Other: Sham - IMT

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Peripheral vascular function and muscle metabolism

    Evaluated using Near Infrared Spectroscopy (NIRS). Tissue perfusion measurement will be performed using an arterial occlusion maneuver. After three minutes of rest to stabilize the initial measurements; [tissue oxygen saturation (StO2) measured in percentage (%), oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb) measured in mmHg], the cuff will be inflated above 250 mmHg up to 280 mmHg , so that the blood flow is completely interrupted, being maintained for a period of five minutes, until the stabilization of the measurements. The variables obtained during the arterial occlusion maneuver will be: StO2 recovery time after occlusion, HHb variation during occlusion and StO2 variation during occlusion. The variables obtained during the exercise will be: variation of HHb and StO2, time to reach the lowest StO2, rate of deoxygenation and reoxygenation and walking economy in relation to HHb and StO2.

    Measured: Up to four weeks

  2. Heart rate and R-R interval recordings

    Patients will be evaluated in the laboratory at 22 degrees Celsius (°C) with relative humidity between 50-60%. They should avoid stimulants, alcohol and exercise the day before the test and refrain from smoking or using bronchodilators for 6 hours before the test. An electrocardiogram will be recorded via Holter (CARDIOS™, Brazil) using a bipolar DII electrode, with three electrodes placed on the chest after asepsis and trichotomy. Holter software will provide time series data of heart intervals, analyzing heart rate variability (HRV) in both the time and frequency domains. In the time domain, indicators of sympathetic and parasympathetic activity will be calculated. In the frequency domain, the low, high and very low frequency bands will be evaluated, with the ratio between low frequency and high frequency, representing sympathovagal balance.

    Measured: Up to four weeks

Secondary outcomes (7)
  1. Subjective perception of effort

    The subjective perception of effort will be assessed through the application of the Modified Borg Scale. This is a quantified vertical scale of 0 to 10, where 0 represents no effort and 10 represents maximum effort. Patients will be instructed to choose a single score that reflects their degree of effort at the moment.

    Measured: Up to four weeks

  2. Lung function

    Spirometry will be performed following the criteria of the American Thoracic Society. All patients will perform at least three maneuvers in a sitting position, using a nose clip and mouthpiece. They will be instructed to perform a maximum inspiration until total lung capacity, followed by a maximum and continuous forced expiration for at least six seconds until reaching the residual volume. The forced expiratory volume in the first second (FEV1) in milliliters (ml), forced vital capacity (FVC) in ml, FEV1/FVC ratio and peak expiratory flow (PEF) in liters per second (L/s) will be determined.

    Measured: Up to four weeks

  3. Respiratory muscle function

    To assess respiratory muscle function, a PowerBreathe device model (KH2 with Breathelink feedback) will be used. The assessment includes measuring maximum inspiratory pressure (MIP) and respiratory muscle resistance in centimeters of water (cmH2O). Patients will remain seated with a nose clip to prevent air leakage. For the PIM, they will exhale to the residual volume and then perform a maximum inspiration held for at least 1.5 seconds, with up to eight repetitions, with the highest value being recorded. Resistance will be measured in an incremental test, starting with 10 cmH2O for two minutes, adding 10 cmH2O with each cycle. The test will be stopped if the patient fails the task or reports significant discomfort or fatigue. Vital signs such as heart rate, respiratory rate and oxygen saturation will be monitored at all times. Dyspnea and fatigue will be assessed with the Modified Borg Scale before and after each test, with words of encouragement provided to optimize performance.

    Measured: Up to four weeks

  4. Thickness and thickening fraction and diaphragmatic mobility

    Diaphragmatic ultrasound is a valuable tool for examining the structure and function of the diaphragm, requiring a convex transducer and a linear transducer. The diaphragm is visualized through the window of the apposition zone, appearing as a three-layer structure: a central hypoechoic muscular layer between two hyperechoic membranes. During diaphragm contraction, ultrasound of the apposition zone window shows muscle shortening and thickening, with measurable mobility during quiet breathing. Atrophy and contraction will be assessed by measuring diaphragm thickness and thickening fraction. A high frequency linear transducer will be positioned in the apposition zone and between the 8th and 9th intercostal spaces. Diaphragmatic thickening will be measured at the end of expiration and at the end of inspiration. The thickening fraction will be calculated as: inspiratory thickening minus expiratory thickening times one hundred, divided by the expiratory thickening measured as a percentage.

    Measured: Up to four weeks

  5. Echointensity and thickness of the quadriceps femoris

    Ultrasonography of the femoral quadriceps will use a linear transducer to capture images transversely over the anterior compartment of the right thigh in B-mode. The patient will be in a semi-Fowler, supine position with knees extended, and muscles relaxed. The transducer will be placed perpendicular to the limb at two-thirds of the distance between the anterior superior iliac spine and lateral knee condyle, marked with a pen. A coupling gel will reduce tissue distortion, and minimal pressure will capture the thickness of the rectus femoris and vastus intermedius. Images will be saved for computer analysis, and the same landmarks will be used in repeated assessments. The echo intensity will be analyzed using a region of interest 50 millimeters (mm) high and wide. A grayscale histogram (0 = black to 255 = white) will determine muscle quality, with higher values indicating potential muscle infiltration or myofibril depletion.

    Measured: Up to four weeks

  6. Feeling of dyspnea

    The Modified Medical Research Council (mMRC) Dyspnea Scale will be used to assess this outcome, measuring the degree of dyspnea during specific daily activities. The mMRC is divided into 4 grades, ranging from 0 (dyspnea with strenuous exercise) to 4 (dyspnea with minimal effort, such as dressing or bathing). This scale is widely used in patients due to its simplicity, ease of use, and correlation with quality of life, prognosis, and distance covered in the six-minute walk test.

    Measured: Up to four weeks

  7. Functional capacity

    Functional capacity will be assessed using a conventional exercise test and a six-minute walk test. The exercise test, carried out first, involves a progressively increasing effort until exhaustion or limiting symptoms appear. Patients will rest 10 minutes before the test and will receive instructions on running and stopping, as well as the correct use of the modified Borg scale. An ergometric treadmill will be used with a ramp protocol up to the patient's tolerable limit. Throughout the test, a 12-lead electrocardiogram will monitor the patient. Blood pressure, peripheral oxygen saturation and dyspnea and fatigue (modified Borg scale) will be recorded at rest, every 2 minutes and after the test. The test will be completed based on the guidelines of the Brazilian Society of Cardiology, and the total distance covered will be recorded as a measure of functional performance.

    Measured: Up to four weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Feb 2025
  2. Study start1 Mar 2025
  3. Primary completion1 Dec 2025 (estimated)
  4. Study completion30 Dec 2025 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Model description
This is a crossover, randomized study, blinded to the evaluator and the researcher responsible for the statistical analysis. The study will evaluate the acute effects of IMT on peripheral muscle metabolism and the autonomic response of patients with COPD and its participants will participate in three groups at different times: IMT-S (strength): IMT to gain inspiratory muscle strength; TMI-R (resistance): TMI to improve inspiratory muscle resistance and Sham - Sham of TMI. All participants randomized to the study will participate in the three groups with a minimum interval of 48 hours between participation in each of the groups. Randomization will be performed to find out the sequence of participation in the three groups for all participants. For statistical analysis, intention-to-treat analysis will be employed and groups will be compared using Students t-test, for continuous variables, or chi-square, for categorical variables. ANOVA split-plot, repeated measures for prim.
Masking
Single blind
Who is masked
Investigator
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06827379
Sponsor's protocol ID
6.669.065
Status last verified
May 2025
First submitted
30 Jan 2025
Last updated
23 May 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Silva DFS, Alcantara BMS, da Silva JRS, Pedrosa R, de Franca EET, Lima JHM. Dizziness, Lower Limb Weakness, and Falls in COPD: A Prospective Longitudinal Pilot Study Using Monthly Home Diaries. Physiother Res Int. 2026 Oct;31(4):e70363. doi: 10.1002/pri.70363.

    PubMed 42910412
  • Borges NMDS, Nogueira PAMS, de Lima DT, Freitas AL, Carneiro HMLO, Gama TO, Pereira DAG, Lima Snr JHM, Pedrosa R, de Franca EET. Acute Effects of Inspiratory Muscle Training with Different Loads on Peripheral Muscle Oxygenation Kinetics and Autonomic Response in Patients with COPD: A Protocol for a Randomized Crossover Study. Int J Chron Obstruct Pulmon Dis. 2026 Oct 16;21:557387. doi: 10.2147/COPD.S557387. eCollection 2026.

    PubMed 42904147
  • Borges NMDS, Lima DT, Morais ABA, Tenorio LNFC, Vieira ST, Carneiro HMLO, Freitas AL, Silva DFS, Silva ED, Paiva MAOS, Silva JVBD, Guedes KP, Gama TO, Fernandes ATDNSF, Azevedo IG, Morais PSA, Pereira DAG, Pedrosa R, Lima JHM, Franca EET. Acute Effect of Inspiratory Muscle Training on Peripheral Tissue Oxygenation Behavior in Individuals With COPD: A Randomized Crossover Study. Physiother Res Int. 2026 Apr;31(2):e70177. doi: 10.1002/pri.70177.

    PubMed 41738531

Questions about this trial

What is this clinical trial studying?

A study testing IMT-S (strength) and IMT-R (resistance) in people with Chronic Obstructive Pulmonary Disease (COPD), run by Federal University of Paraíba at 1 site in Brazil.

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 3 inclusion and 4 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: enrolling by invitation, as of the sponsor's last update on 23 May 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 Brazil. 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. Some participants in this study may receive a placebo. 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?

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?

Peripheral vascular function and muscle metabolism (time frame: Up to four weeks). The study lists 2 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 NCT06827379, which also lists 3 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 23 May 2025.

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Clinical Trial NCT06827379 | AzTrials