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Chronic Obstructive Pulmonary DiseaseNCT02660437

pCO2 Oscillations During Exercise: Relation to Cerebral Blood Flow and to Cognitive Dysfunction in COPD

A study testing Pulmonary Rehabilitation program in people with Chronic Obstructive Pulmonary Disease, run by Schön Klinik Berchtesgadener Land at 1 site in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Investigators wish to identify a relationship between substantial changes in carbon dioxide partial-pressure (pCO2), which frequently occur during the transitions from rest to exercise (ΔpCO2 >4 millimeters of mercury [mmHg] from baseline), and the prevalence of cognitive dysfunction in COPD. Read more about this study

Who is it for?
Ages 40 to 80 years
Conditions the study is for
Chronic Obstructive Pulmonary Disease
What is being tested?
Pulmonary Rehabilitation program
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
91 participants
Where
1 siteGermany
Study dates
Mar 2016to Jul 2018
Phase
Interventional
Are there results?
None posted in the registry

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 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patients with Chronic Obstructive Pulmonary Disease (COPD) in Global Initiative on Obstructive Lung Disease (GOLD) stages II to IV
  • COPD patients with mild to moderate cognitive impairment (MCI-group: n=100) and without cognitive impairment (Control-group: n=60)
  • Normotensive (Blood Pressure range: 101-143/62-91 millimeters of mercury [mmHg])

Who cannot join

  • Resting partial pressure of oxygen in arterial blood (paO2) <55 millimeters of mercury [mmHg]
  • Resting partial pressure of carbon dioxide in arterial blood (paCO2) >45 millimeters of mercury [mmHg]
  • last exacerbation ≤4weeks
  • severe cognitive impairment/dementia
  • other neuropsychiatric symptoms

Trial locations and contacts

1 site in 1 country.

Germany1 site
  • Klinikum Berchtesgadener Land der Schön-Kliniken

    Schönau am Königssee, 83471

Other trials in Germany

About this study

Official title: Carbon Dioxide Partial Pressure Oscillations During Exercise: Relation to Cerebral Blood Flow Regulation and and to the Prevalence of Cognitive Dysfunction in COPD

Investigators wish to identify a relationship between substantial changes in carbon dioxide partial-pressure (pCO2), which frequently occur during the transitions from rest to exercise (ΔpCO2 >4 millimeters of mercury [mmHg] from baseline), and the prevalence of cognitive dysfunction in COPD. In particular, it is anticipated to investigate the vascular effect of pCO2 oscillations in the regulation of cerebral blood flow (CBF) during exercise and its impact on cognitive function in Chronic Obstructive Pulmonary Disease (COPD). Furthermore, this study aims to examine whether major pCO2 oscillations have prognostic value in cognitive deterioration at 6, 12, and 18-month follow-up. In addition, the acute effect of 3-week pulmonary rehabilitation (PR) on cognitive function will be explored. The evaluation of cognitive function will be performed by the use of Standardized Mini Mental State Examination (SMMSE), Addenbrooke's Cognitive Examination (ACE-R), Montreal Cognitive Assessment (MoCA), and Telephone Interview for Cognitive Status (TICS) assessing several cognitive domains (cognitive scores) whereas Stroop test [color reading interference] will be used for measuring cognitive performance (Reaction-Time).

Read the detailed description

Cerebral Blood Flow (CBF) regulation is crucial for the adequate oxygen supply to the brain and the sustenance of cerebrovascular reserve capacity. A fundamental physiologic regulator of CBF is the carbon dioxide partial pressure (pCO2), which determines the dilatation or contraction of cerebral vasculature. CBF regulation response has been found to be strongly dependent upon pCO2 but much less so upon changes in arterial oxygen saturation. CBF is highly sensitive to pCO2 changes which cause pronounced-vasodilatation in increased pCO2 (CBF augmentation) or vasoconstriction in decreased pCO2 levels (CBF diminution). During cerebral activation and increased metabolism, cerebral arterioles dilate contributing to increase CBF but this process is often challenged during exercise and has a potential impact on cognitive function. CBF is linked to cognitive function while serum level of Brain Derived Neurotrophic Factor (BDNF) has been shown as a critical driving force behind neural plasticity with a potential utility as a biomarker of cognitive decline.

Investigators assume that major pCO2 oscillations during exercise (ΔpCO2 >4 millimeters of mercury [mmHg] from baseline) as a reflection of the abnormality in ventilatory efficiency/drive, lead to overall and local disturbances of cerebral blood flow (CBF) and thus can be associated to increased prevalence of cognitive dysfunction in patients with Chronic Obstructive Pulmonary Disease (COPD). Moreover, investigators hypothesize that patients with major pCO2 oscillations during exercise may develop worse cognitive impairment in several cognitive domains and greater cognitive decline compared to "isocapnic" patients at 6, 12, and 18-month follow-up. Inpatient PR may benefit cognitive function by improving breathing (diminishing pCO2 oscillations), therefore improving CBF, and by increasing cerebral neural activation through exercise.

With regard to cognitive dysfunction, which is associated to increased all-cause mortality and disability, investigators wish:

(A) to detect a relationship between major pCO2 oscillations during exercise and increased prevalence of cognitive dysfunction in COPD; (B) to investigate the impact of different pCO2 transitory-patterns (1. pCO2: decline/ hypocapnic, 2. steady/ isocapnic, 3. increase/ hypercapnic) on CBF regulation and cognitive function; (C) to examine whether major pCO2 oscillations can be a determinant of greater cognitive deterioration in several cognitive domains at 6, 12, and18-month follow-up and (D) to explore the acute effect of 3-week PR on pCO2 oscillations and CBF in respect to cognitive function in COPD patients with cognitive impairment.

The evaluation of cognitive function will be performed by the use of Standardized Mini Mental State Examination (SMMSE), Addenbrooke's Cognitive Examination (ACE-R), Montreal Cognitive Assessment (MoCA) and Telephone Interview for Cognitive Status (TICS) assessing several cognitive domains (cognitive scores) whereas Stroop test will be used for measuring cognitive performance (Reaction-Time).

Being tested
Pulmonary Rehabilitation program
Keywords
COPD, Carbon dioxide partial pressure (pCO2), Cerebral blood flow (CBF), Cognitive dysfunction, Mild/Moderate Cognitive Impairment (MCI), Pulmonary Rehabilitation (PR), Standardized Mini Mental State Examination (SMMSE), Addenbrooke's Cognitive Examination (ACE-R), Montreal Cognitive Assessment (MoCA), Telephone Interview for Cognitive Status (TICS), Stroop test (Reaction Time)
Medical subject headings
Pulmonary Disease, Chronic Obstructive, Cognitive Dysfunction

What participants receive

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

  • Pulmonary Rehabilitation programOther

    Also called Exercise intervention

    Patients will attend a comprehensive 3-week PR program (12sessions/ 60min·day) including high intensive interval exercise equivalent to 100% of peak work rate (WRpeak) with 30sec work periods interspersed with 30sec rest periods for 30min and light resistance training (3muscle groups/ 4sets each/10repetitions; ~30min).

Study groups in NCT02660437
Study groupRoleWhat they receive
Effect of PR in MCI-groupActive comparatorEvaluation of the acute effect of a 3-week Pulmonary Rehabilitation (PR) program in cognitive function of MCI-Group using SMMSE, ACE-R, MoCA, TICS and Stroop test clinical instruments in reference to potential changes in pCO2 oscillation patterns (post-PR). Intervention: Pulmonary Rehabilitation program; 12 sessions of exercise training/breathing techniques.
Receives: Other: Pulmonary Rehabilitation program
Effect of PR in control-groupPlacebo comparatorEvaluation of the acute effect of a 3-week Pulmonary Rehabilitation (PR) program in cognitive function of control-group using SMMSE, ACE-R, MoCA, TICS and Stroop test clinical instruments in reference to potential changes in pCO2 oscillation patterns (post-PR). Intervention: Pulmonary Rehabilitation program; 12 sessions of exercise training/breathing techniques.
Receives: Other: Pulmonary Rehabilitation program

What is being measured

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

  1. Carbon-dioxide partial pressure oscillations (ΔpCO2, mmHg)

    Changes in transcutaneous pCO2 (ΔpCO2, mmHg from baseline values) during Cycle-Endurance Test (CET) at 75% of peak Work Rate (WRpeak). The pCO2 oscillations will be transcutaneous monitored and continuously recorded by the use of "SenTec" Digital Monitoring System (pre/post measurements): 1st measurement during a CET prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement during a CET at the end of PR program (post-PR).

    Measured: Day 4-21

Secondary outcomes (9)
  1. Cognitive Dysfunction (yes/no)

    Screening of Cognitive Dysfunction according to Petersen's criteria:

    1. Consistent memory complaints preferably corroborated by a close-informant.
    2. Objective characterization of specific deficits in memory and/or other cognitive domains, as indicated by a poor performance on MoCA (<26 points), MMSE (<25 points), ACE-R (<88 points) and TICS (<33 points).
    3. Preserved ability to perform activities of daily living (ADLs), or minimal impairment if considering instrumental ADLs.
    4. Normal global cognitive function.
    5. Absence of dementia (Clinical Dementia Rating Scale (CDR ≤1 point)).

    Measured: Day 1-3

  2. Cognitive Impairment (Standardized Mini-Mental State Examination [SMMSE, scores])

    Evaluation of Cognitive Impairment (CI) by the use of clinical instrument of the Standardized Mini-Mental State Examination (SMMSE, scores); 1st measurement prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement at the end of PR program (post-PR).

    Measured: Day 1-21

  3. Cognitive Impairment (Addenbrooke's Cognitive Examination [ACE-R])

    Evaluation of Cognitive Impairment (CI) by the use of clinical instrument of the Addenbrooke's Cognitive Examination (ACE-R scores); 1st measurement prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement at the end of PR program (post-PR).

    Measured: Day 1-21

  4. Cognitive Impairment (Montreal-Cognitive Assessment [MoCA, scores])

    Evaluation of Cognitive Impairment (CI) by the use of clinical instrument of the Montreal-Cognitive Assessment (MoCa scores); 1st measurement prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement at the end of PR program (post-PR).

    Measured: Day 1-21

  5. Cognitive Impairment (Telephone Interview for Cognitive Status [TICS])

    Evaluation of Cognitive Impairment (CI) by the use of clinical instrument of the Telephone Interview for Cognitive Status (TICS scores); 1st measurement prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement at the end of PR program (post-PR).

    Measured: Day 1-21

  6. Cognitive Performance (Stroop test [reaction-time, seconds])

    Assessment of cognitive performance (Stroop test - reaction-time, seconds) before and immediately after Cycle-Endurance Test (CET) at 75% of WRpeak. Cognitive performance will be measured by the use of Stroop-test (pre/post measurements): 1st measurement during a CET prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement during a CET at the end of PR program (post-PR).

    Measured: Day 4-21

  7. Cerebral Blood Flow Velocity (CBFv, cm/sec)

    Measurement of Cerebral Blood Flow velocity (CBFv, cm/sec) as surrogate of Cerebral Blood Flow (CBF) before and immediately after Cycle-Endurance Test (CET) at 75% of WRpeak. Cerebral Blood Flow velocity (CBFv) will be measured by the use of transcranial Doppler ultrasonography (pre/post measurements): 1st measurement during a CET prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement during a CET at the end of PR program (post-PR).

    Measured: Day 4-21

  8. Frontal cortex cerebrovascular oxygen saturation (Tissue Oxygen Saturation [TOI, %])

    Measurement Tissue Oxygen Saturation (TOI, %) as an index of frontal cortex cerebrovascular oxygen saturation during Cycle-Endurance Test (CET) at 75% of WRpeak. Tissue oxygen saturation (TOI, %) will be continuously measured by the use of Near-Infrared Spectroscopy (NIRS-method; pre/post measurement): 1st measurement during a CET prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement during a CET at the end of PR program (post-PR).

    Measured: Day 4-21

  9. Frontal cortex cerebrovascular oxygen saturation (Changes in Deoxygenated Haemoglobin [ΔHHb, μM/cm])

    Measurement of the changes in Deoxygenated Haemoglobin (ΔHHb) in micrometer per centimeter (μM/cm) as an index of frontal cortex cerebrovascular oxygen saturation during Cycle-Endurance Test (CET) at 75% of WRpeak. Changes in Deoxygenated Haemoglobin (ΔHHb, μM/cm) will be continuously measured by the use of Near-Infrared Spectroscopy (NIRS-method; pre/post measurement): 1st measurement during a CET prior to the participation in a 3-week (12 sessions) Pulmonary Rehabilitation program (pre-PR); 2nd measurement during a CET at the end of PR program (post-PR).

    Measured: Day 4-21

Timeline

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

  1. First posted21 Jan 2016 (estimated)
  2. Study startMar 2016
  3. Primary completionMar 2018
  4. Study completionJul 2018

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
Basic science
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
91 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02660437
Sponsor's protocol ID
RESPIRE2-8465
Status last verified
Feb 2019
First submitted
8 Jan 2016
Last updated
28 Feb 2019
Results posted
No
Data monitoring committee
No
Individual data sharing
No

Publications

  • Payne SJ, Mohammad J, Tisdall MM, Tachtsidis I. Effects of arterial blood gas levels on cerebral blood flow and oxygen transport. Biomed Opt Express. 2011 Mar 25;2(4):966-79. doi: 10.1364/BOE.2.000979.

    PubMed 21483617
  • Ogoh S, Tsukamoto H, Hirasawa A, Hasegawa H, Hirose N, Hashimoto T. The effect of changes in cerebral blood flow on cognitive function during exercise. Physiol Rep. 2014 Sep 28;2(9):e12163. doi: 10.14814/phy2.12163. Print 2014 Sep 1.

    PubMed 25263210
  • Shimada H, Makizako H, Doi T, Yoshida D, Tsutsumimoto K, Anan Y, Uemura K, Lee S, Park H, Suzuki T. A large, cross-sectional observational study of serum BDNF, cognitive function, and mild cognitive impairment in the elderly. Front Aging Neurosci. 2014 Apr 15;6:69. doi: 10.3389/fnagi.2014.00069. eCollection 2014.

    PubMed 24782766
  • Ito H, Ibaraki M, Kanno I, Fukuda H, Miura S. Changes in the arterial fraction of human cerebral blood volume during hypercapnia and hypocapnia measured by positron emission tomography. J Cereb Blood Flow Metab. 2005 Jul;25(7):852-7. doi: 10.1038/sj.jcbfm.9600076.

    PubMed 15716851
  • Petersen RC, Smith GE, Waring SC, Ivnik RJ, Tangalos EG, Kokmen E. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol. 1999 Mar;56(3):303-8. doi: 10.1001/archneur.56.3.303.

    PubMed 10190820
  • Van der Elst W, Van Boxtel MP, Van Breukelen GJ, Jolles J. The Stroop color-word test: influence of age, sex, and education; and normative data for a large sample across the adult age range. Assessment. 2006 Mar;13(1):62-79. doi: 10.1177/1073191105283427.

    PubMed 16443719
  • Valdueza JM, Balzer JO, Villringer A, Vogl TJ, Kutter R, Einhaupl KM. Changes in blood flow velocity and diameter of the middle cerebral artery during hyperventilation: assessment with MR and transcranial Doppler sonography. AJNR Am J Neuroradiol. 1997 Nov-Dec;18(10):1929-34.

    PubMed 9403456
  • Vogiatzis I, Louvaris Z, Habazettl H, Andrianopoulos V, Wagner H, Roussos C, Wagner PD, Zakynthinos S. Cerebral cortex oxygen delivery and exercise limitation in patients with COPD. Eur Respir J. 2013 Feb;41(2):295-301. doi: 10.1183/09031936.00016312. Epub 2012 May 3.

    PubMed 22556019

Questions about this trial

What is this clinical trial studying?

A study testing Pulmonary Rehabilitation program in people with Chronic Obstructive Pulmonary Disease, run by Schön Klinik Berchtesgadener Land at 1 site in Germany.

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 5 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: finished, as of the sponsor's last update on 28 Feb 2019. 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 Germany. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Carbon-dioxide partial pressure oscillations (ΔpCO2, mmHg) (time frame: Day 4-21). 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 NCT02660437, which also lists 8 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 28 Feb 2019.

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