Diaphragmatic Function as a Biomarker

Study Purpose

Dyspnea is among the most common symptoms in patients with respiratory diseases such as Asthma, chronic obstructive pulmonary disease (COPD), Fibrosis, and Pulmonary Hypertension. However, the pathophysiology and underlying mechanisms of dyspnea in patients with respiratory diseases are still poorly understood. Diaphragm dysfunction might be highly prevalent in patients with dyspnea and respiratory diseases. The association of diaphragm function and potential prognostic significance in patients with respiratory diseases has not yet been investigated.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years and Over
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - patient has one of the following lung diseases: COPD, bronchial asthma, pulmonary fibrosis, pulmonary hypertension.
  • - is 18 years or older.
  • - is mentally and physically able to understand the study and to follow instructions.
  • - are legally competent.
  • - signed declaration of consent.

Exclusion Criteria:

  • - BMI > 35.
  • - current or treatments or diseases in the past which could influence the evaluation of the study.
  • - Expected lack of willingness to actively participate in study-related measures.
  • - alcohol or drug abuse.
  • - disc herniation/prolapse.
  • - epilepsy.
  • - wheelchair bound.
  • - in custody due to an official or court order.
  • - in a dependent relationship or employment relationship with investigating physician or one of their deputy.
- emergency inpatient hospital stay within 4 weeks before study-specific examinations

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

RWTH Aachen University
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Michael Dreher, MDBinaya Regmi, MDJens Spiesshoefer, MDMustafa ElfeturiBenedikt JörnFaniry RatsimbaFelix Wagner
Principal Investigator Affiliation Uniklinik RWTH AachenUniklinik RWTH AachenUniklinik RWTH AachenUniklinik RWTH AachenUniklinik RWTH AachenUniklinik RWTH AachenUniklinik RWTH Aachen
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries Germany

The disease, disorder, syndrome, illness, or injury that is being studied.

Dyspnea; Asthmatic, COPD, Fibrosis, Pulmonary Hypertension, Asthma, Dyspnea
Additional Details

The aim of the present project is to comprehensively measure respiratory muscle function and strength in patients with respiratory diseases. The investigators attempt to recruit 800 patients across four disease groups (Asthma, COPD, Fibrosis, and Pulmonary Hypertension) and the investigators intend to measure diaphragm and accessory respiratory muscle function and strength, lung function, and exercise tolerance, as well as the participants' symptom burden during one day at baseline in the investigators' lab. Thereafter, the investigators will follow up on patients by phone 3 months, 6 months, 12 months and 18 months after the investigators have seen them in the investigators' lab. Based on these results, not only the association between dyspnea exercise tolerance and diaphragm function in patients with respiratory diseases can be assessed, but also the prognostic significance of diaphragm dysfunction in these patients can be determined. As such, hospitalization and exacerbation requiring the intake of steroids will be assessed and followed up on by phone, and therefore the prognostic significance of diaphragm dysfunction in predicting hospitalization and the intake of steroids can be determined.

Arms & Interventions


: Patients with Asthma

: Patients with COPD

: Patients with Fibrosis

: Patients with Pulmonary Hypertension


Diagnostic Test: - Diaphragm Ultrasound

Ultrasound of the Diaphragm at the end of inspiration and expiration

Diagnostic Test: - Intercostal Muscle Ultrasound

Ultrasound of the Intercostal Muscles at the end of inspiration and expiration

Diagnostic Test: - Borg scale

Questionnaire for Perceived Exertion (Borg Rating of Perceived Exertion Scale)

Diagnostic Test: - MRC Breathlessness Scale

The MRC Dyspnoea Scale allows the patients to indicate the extent to which their breathlessness affects their mobility.

Diagnostic Test: - Respiratory Questionaire

Specialized respiratory questionnaire with different domains (Emotional Domain, Dyspnea Domain, Mastery Domain, Fatigue Domain)

Diagnostic Test: - GINA classification of Asthma

Patients are classified according to the GINA classification of Asthma.

Diagnostic Test: - Measurement of respiratory mouth pressure

Inspiratory and expiratory Measurement of respiratory mouth pressure

Diagnostic Test: - SNIP

Measurement of Sniff Nasal Inspiratory Pressure

Diagnostic Test: - 6-minute walking distance

The maximum walking distance achieved in 6 minutes

Diagnostic Test: - 60 seconds sit-to-stand test

number of repetitions achieved in sitting down and standing up in 60 seconds

Diagnostic Test: - Electromyography

electromyography of the muscles of respiration via superficial electrodes

Diagnostic Test: - Lung Function

Measurement of lung function via body plethysmography

Diagnostic Test: - CAT-Questionnaire

COPD Assessment Test (CAT)

Diagnostic Test: - European Society of Cardiology (ESC)/ European Respiratory Society (ERS) risk group

Patients with pulmonary hypertension are classified according to the ESC/ERS risk group.

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International Sites

RWTH Aachen University Hospital, Aachen, North Rhine-westphalia, Germany




RWTH Aachen University Hospital

Aachen, North Rhine-westphalia, 52074

Site Contact

Jens Spiesshoefer, PhD



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