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RecruitingNCT04849806SNAP-COPDUpdated Jan 28, 2026

Sympathetic Nerve Activity Predictors in Patients With Chronic Obstructive Pulmonary Disease

An observational study in COPD, Sympathetic Nervous System Diseases and Catecholamine; Overproduction, sponsored by RWTH Aachen University. Recruiting at 1 site in Germany. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-28.

Sponsored by RWTH Aachen University · Observational

From the registry’s dates

  • Started May 2022; still recruiting 4 years 6 months later.
Study type
Observational
Model
Case-control
Time perspective
Prospective
Enrollment
135
Ages
18 Years and older
Sex
All
01

Study summary

The project will be pursued in our respiratory, autonomic nervous system physiology laboratory (Respiratory, autonomic nervous system physiology laboratory, Department of Pneumology and Intensive Care Medicine, RWTH Aachen University Hospital; Head of Department: Professor Michael Dreher).

Overactivity of the sympathetic nerve activity (SNA) axis with "centrally" increased heart rate and peripheral vasoconstriction is a known phenomenon in patients with systolic heart failure (HF) and has recently been described in patients with primary lung disease as seen in chronic obstructive pulmonary disease (COPD).

However, systematic analyses on this clinically relevant topic are currently lacking.

Thus, using a comprehensive, multimodal approach and state-of-the-art technology, this research project is designed to determine the extent and nature of increased SNA in COPD (AIM 1) and evaluate the underlying mechanisms (AIM 2).

The project will address the following hypotheses:

  1. In COPD, concomitant obstructive sleep apnea is independently associated with increased SNA.
  2. Precapillary pulmonary hypertension (PH), inspiratory muscle dysfunction and systemic inflammation describe a COPD phenotype characterised by increased SNA with a different subtype.
Read the detailed description

The project will be pursued in our respiratory, autonomic nervous system physiology laboratory (Respiratory, autonomic nervous system physiology laboratory, Department of Pneumology and Intensive Care Medicine, RWTH Aachen University Hospital; Head of Department: Professor Michael Dreher).

Overactivity of the sympathetic nerve activity (SNA) axis is a known phenomenon in patients with systolic heart failure (HF) and has recently been described in patients with primary lung disease as seen in chronic obstructive pulmonary disease (COPD).

Thus, insights into the nature of and factors involved in increased SNA in COPD are urgently needed.

Potentially obstructive sleep apnea (OSA) with not only repetitive obstructions but also additional hypoxia and poor sleep quality additively increase SNA in COPD. In addition, inspiratory muscle dysfunction (if adequately measured by magnetic diaphragm stimulation studies and comprehensive diaphragm ultrasound) with related hypercapnia, pulmonary hypertension (PH) and systemic inflammation all likely also impact on SNA in COPD.

However, systematic analyses on this clinically relevant topic are currently lacking.

Thus, using a comprehensive, multimodal approach and state-of-the-art technology, this research project is designed to determine the extent and nature of increased SNA in COPD (AIM 1) and evaluate the underlying mechanisms (AIM 2). The project will address the following hypotheses:

  1. In COPD, concomitant OSA with poor sleep is independently associated with increased SNA,.
  2. PH, inspiratory muscle dysfunction and systemic inflammation describe a COPD phenotype characterised by increased SNA, manifesting differently.

To test these hypotheses COPD patients without an established cardiovascular disease will be enrolled and the extent, nature and mechanism of SNA increase compared with healthy controls matched in a 3:1 ratio for age, sex and body mass index (BMI).

Invasive assessment of muscle SNA to the point of single unit recordings with analysis of single postganglionic sympathetic firing, and hence SNA drive to the peripheral vasculature, is the gold standard for quantification of SNA in humans but is only available in a few centres worldwide because it is costly, time consuming and requires a high level of training.

A small substudy will investigate the short term acute treatment effects of non-invasive ventilation and oxygen supplementation on SNA in patients with COPD.

02

Conditions studied

  • COPD
  • Sympathetic Nervous System Diseases
  • Catecholamine; Overproduction
03

In context

Pulmonary Disease, Chronic Obstructive

5,520 studies on the registry are indexed under Pulmonary Disease, Chronic Obstructive; 856 are open to participants now.

This study's planned enrollment of 135 is below the median of 158 across 1,497 observational studies indexed under Pulmonary Disease, Chronic Obstructive.

Browse Pulmonary Disease, Chronic Obstructive studies →

Lead sponsor

RWTH Aachen University is the lead sponsor of 230 studies on the registry; 19 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Probability sample

Study population

COPD patients (n=60) Controls (n=20) COPD patients without an established cardiovascular disease will be enrolled and the extent, nature and mechanism of SNA increase compared with healthy controls matched in a 3:1 ratio for age, sex and body mass index (BMI).

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age ≥ 18
  • Ability and willingness to give to participate in the study

Exclusion criteria

Exclusion Criteria:

  • Atrial fibrillation
  • Active pacing of the heart by a cardiac pacemaker (i.e. no intrinsic heart rate)
  • Clinically pre-established cardiovascular disease (e.g. arterial hypertension or systolic heart failure)
  • In-patient stay in the hospital within the last 4 weeks prior to the study examination date
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Observational model
Case-control
Time perspective
Prospective
Enrollment
135 participants (estimated)
Patient registry
No
Biospecimen retention
Samples with dna

Groups and cohorts

  • COPD patients (n=100)

    The following parameters will be determined in 100 consecutive patients with COPD without established cardiovascular disease (i.e. without an indication for beta blocker therapy or other pharmacological treatments attacking on the neurohormonal pathways like angiotensin-converting enzyme inhibitors or mineralocorticoid receptor antagonists). 1. OSA severity. 2. Determination of PH and right HF severity (defined as tricuspid annular plane systolic excursion ≤14 mm) and pulmonary arterial pressure (PAsys) using transthoracic echocardiography; 3. Comprehensive lung function and inspiratory muscle function testing ;Assessment of daytime hypoxia (PaO2 \<55 mmHg) and hypercapnia (PaCO2 \>45 mmHg) using capillary blood gas analysis; 4. Assessment of systemic inflammation

    Diagnostic Test: Assessments of the sympathetic nerve activity axis · Diagnostic Test: OSA severity · Diagnostic Test: Determination of PH and right HF severity · Diagnostic Test: Comprehensive lung function and inspiratory muscle function testing. · Diagnostic Test: Assessment of systemic inflammation

  • Controls (n=35)

    (and in a group of healthy controls \[3:1\] matched for age, sex and BMI).

    Diagnostic Test: Assessments of the sympathetic nerve activity axis · Diagnostic Test: OSA severity · Diagnostic Test: Determination of PH and right HF severity · Diagnostic Test: Comprehensive lung function and inspiratory muscle function testing. · Diagnostic Test: Assessment of systemic inflammation

Interventions

  • Diagnostic testAssessments of the sympathetic nerve activity axis

    For assessment sympathovagal balance (SVB), HRV and dBPV will be analysed using a 3-lead electrocardiogram (sampling rate 1000Hz) and a continuous non-invasive arterial blood pressure signal (CNAP® technology, sampling rate 100Hz). HRV (ms2 based on continuously recorded variability in RR intervals) and (diastolic) BPV (expressed as mmHg2 based on continuously recorded variability in diastolic BP) will be computed by time domain analysis and by frequency domain analysis and presented as the high frequency component (HF; 0.15-0.4 Hz), low frequency component (LF; 0.04-0.15 Hz), their relative ratio (LF/HF), and the very low frequency component (VLF; 0.0-0.04 Hz) for both HRV and dBPV . Muscle SNA will be recorded via a tungsten microelectrode carefully placed in the peroneal nerve. Plasma catecholamines will also be assessed.

  • Diagnostic testOSA severity

    OSA is defined as apnoea-hypopnoea index \[AHI\] \>15/h and obstructive apnoea index \[OAI\] \>5/h) and sleep architecture

  • Diagnostic testDetermination of PH and right HF severity

    (defined as tricuspid annular plane systolic excursion ≤14 mm) and pulmonary arterial pressure (PAsys) using transthoracic echocardiography

  • Diagnostic testComprehensive lung function and inspiratory muscle function testing.

    Respiratory Muscle strength and function testing as previously established by our group and Assessment of daytime hypoxia (PaO2 \<55 mmHg) and hypercapnia (PaCO2 \>45 mmHg) using capillary blood gas analysis.

  • Diagnostic testAssessment of systemic inflammation

    Based on blood samples taken.

06

What researchers measure

Primary outcomes

  1. Assessments of the sympathetic nerve activity axis (Non invasive)

    sympathovagal balance (SVB), HRV and dBPV will be analysed using a 3-lead electrocardiogram (sampling rate 1000Hz) and a continuous non-invasive arterial blood pressure signal (CNAP® technology, sampling rate 100Hz). HRV (ms2 based on continuously recorded variability in RR intervals) and (diastolic) BPV (expressed as mmHg2 based on continuously recorded variability in diastolic BP) will be computed by time domain analysis and by frequency domain analysis and presented as the high frequency component (HF; 0.15-0.4 Hz), low frequency component (LF; 0.04-0.15 Hz), their relative ratio (LF/HF), and the very low frequency component (VLF; 0.0-0.04 Hz) for both HRV and dBPV .

    Time frame: 2 years

  2. Assessments of the sympathetic nerve activity axis (Invasive)

    Muscle SNA will be recorded via a tungsten microelectrode carefully placed in the peroneal nerve Plasma catecholamines will be assessed Muscle SNA will be recorded via a tungsten microelectrode carefully placed in the peroneal nerve Plasma catecholamines will be assessed Muscle SNA will be recorded via a tungsten microelectrode carefully placed in the peroneal nerve. Plasma catecholamines will be assessed

    Time frame: 2 years

Secondary outcomes

  1. OSA severity

    See above

    Time frame: 2 years

  2. Determination of PH and right HF severity

    See above

    Time frame: 2 years

  3. Comprehensive lung function and inspiratory muscle function testing as previously described by our group

    See above

    Time frame: 2 years

  4. Assessment of systemic inflammation

    See above

    Time frame: 2 years

07

Study locations

1 of 1 sites recruiting
08

References and documents

Publications

  • Spiesshoefer J, Becker S, Tuleta I, Mohr M, Diller GP, Emdin M, Florian AR, Yilmaz A, Boentert M, Giannoni A. Impact of Simulated Hyperventilation and Periodic Breathing on Sympatho-Vagal Balance and Hemodynamics in Patients with and without Heart Failure. Respiration. 2019;98(6):482-494. doi: 10.1159/000502155. Epub 2019 Aug 28. PubMed 31461730 ↗
  • Spiesshoefer J, Herkenrath S, Henke C, Langenbruch L, Schneppe M, Randerath W, Young P, Brix T, Boentert M. Evaluation of Respiratory Muscle Strength and Diaphragm Ultrasound: Normative Values, Theoretical Considerations, and Practical Recommendations. Respiration. 2020;99(5):369-381. doi: 10.1159/000506016. Epub 2020 May 12. PubMed 32396905 ↗
  • Spiesshoefer J, Henke C, Herkenrath S, Brix T, Randerath W, Young P, Boentert M. Transdiapragmatic pressure and contractile properties of the diaphragm following magnetic stimulation. Respir Physiol Neurobiol. 2019 Aug;266:47-53. doi: 10.1016/j.resp.2019.04.011. Epub 2019 Apr 25. PubMed 31029769 ↗
  • Dreher M, Neuzeret PC, Windisch W, Martens D, Hoheisel G, Groschel A, Woehrle H, Fetsch T, Graml A, Kohnlein T. Prevalence Of Chronic Hypercapnia In Severe Chronic Obstructive Pulmonary Disease: Data From The HOmeVent Registry. Int J Chron Obstruct Pulmon Dis. 2019 Oct 18;14:2377-2384. doi: 10.2147/COPD.S222803. eCollection 2019. PubMed 31695357 ↗

Individual participant data

Plan to share: Undecided

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jan 28, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04849806
Collaborators
DFG - Deutsche Forschungs Gemeinschaft (German Research Foundation)
Responsible party
Jens Spießhöfer (Jens Spiesshoefer, MD, PhD Candidate, Group head Respiratory Physiology, RWTH Aachen University) — Principal investigator
First posted
Apr 19, 2021
Start date
May 10, 2022
Primary completion
Dec 2028 (estimated)
Completion
Dec 2028 (estimated)
Last update
Jan 28, 2026

Study contacts

Michael Dreher, Professor
Contact
mdreher@ukaachen.de
+492418088763 ext. 88763
Jens Dr. Spiesshoefer, MD
Contact
jspiesshoefe@ukaachen.de
+492418037036
Michael Dreher, Professor
study director · RWTH Aachen University
Jens Spiesshoefer, MD
principal investigator · RWTH Aachen University
Binaya Regmi, MD
study chair · RWTH Aachen University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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