Cardiovascular SystemNCT05866848
Effects of Caffeine on Cerebral Blood Flow
A study testing Anhydrous caffeine (45mg) and Anhydrous caffeine (120mg) in people with Cardiovascular System, run by Escola Superior de Tecnologia da Saúde de Coimbra at 1 site in Portugal.
Trial summary
The goal of this clinical trial is to evaluate in clinically healthy young people if: after caffeine ingestion, there are variations in blood velocity of the middle cerebral arteries (VMCA), this variation is dependent on the administered dose. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Cardiovascular System
- What is being tested?
- Anhydrous caffeine (45mg) and Anhydrous caffeine (120mg)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 45 participants
- Where
- 1 sitePortugal
- Study dates
- 1 May 2021to 1 Jun 2021
- 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 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- clinically healthy young people
Who cannot join
- Individuals with hypertension, high cholesterol, diabetes, arrhythmias, carotid sinus syndrome, severe carotid stenosis and who were in an unstable clinical situation.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Caffeine on Cerebral Blood Flow in Clinically Healthy Young People
The goal of this clinical trial is to evaluate in clinically healthy young people if:
- after caffeine ingestion, there are variations in blood velocity of the middle cerebral arteries (VMCA),
- this variation is dependent on the administered dose.
Transcranial Doppler ultrasonography was used to record blood VMCA in three groups of 15 clinically healthy young adults each - no caffeine, low caffeine (45 mg) and high caffeine group (120 mg). Transcranial Doppler ultrasonography provided simultaneous bilateral VMCA measurements while subjects performed functional tests (hyperventilation and hypoventilation orders) and three cognitive activities (Test 1, short-term remembering, Test 2, solving a vocabulary problem, and Test 3, solving a math problem) each in 31-second tests with 1-minute rest between them. Participants were assessed before and 30 minutes after caffeine ingestion.
Read the detailed description
Were used in the study, Capsules dosed with 45mg and 120 mg of anhydrous caffeine and flour capsules as a placebo. In the preparation of the capsules, a semi-automatic capsulator No. 0 (Capsunorm® by Tecnyfarma®) were used, colorless hard gelatin capsules No. 0 by Acopharma® and anhydrous caffeine (Biochem®, C.A.S. 58-08-2).
Viasys Sonara transcranial Doppler unit and a 2 MHz probe were used to sample the middle cerebral artery at depths of 60 millimeters, using emission doppler pulsed performing spectral analysis in real time. Two probes (bilaterally) of 2MHz were placed at a depth between 55 and 60 mm, thus making it possible to analyse both middle cerebral arteries simultaneously.
Each participant was asked not to ingest caffeine and exercise vigorously for at least 12 hours before the assessment. In the case of smokers, they were also asked not to smoke for at least 2 hours before the evaluation. The laboratory had medium luminosity, silent and controlled temperature (23º/24ºC). To avoid inter-observer errors, all examinations were performed by the same investigator who was not aware of what dose was/had been administered to the participant.
Subjects were tested while seated in a reclining chair located in a dimly lit, sound-attenuated room and performed the activities with their eyes closed.
- Conditions
- Cardiovascular System
- Being tested
- Placebo, Anhydrous caffeine (45mg), Anhydrous caffeine (120mg)
- Keywords
- Transcranial Doppler ultrasonography, Middle Cerebral Artery, functional tests, cognitive activities, caffeine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboOther
Flour capsules as a placebo.
Anhydrous caffeine (45mg)Other
Capsules dosed with 45mg of anhydrous caffeine.
Anhydrous caffeine (120mg)Other
Capsules dosed with 120mg of anhydrous caffeine.
| Study group | Role | What they receive |
|---|---|---|
| No caffeine | Placebo comparator | The control group took flour capsules. Receives: Other: Placebo |
| Low caffeine | Experimental | Group with relatively small amount of caffeine (45 mg) administered. Receives: Other: Anhydrous caffeine (45mg) |
| High caffeine | Experimental | Group with greater amount of caffeine (120 mg) administered. Receives: Other: Anhydrous caffeine (120mg) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in Mean Velocity (Basal)
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Mean Velocity (Hypoventilation)
By performing Hypoventilation, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Mean Velocity (Hyperventilation)
By performing Hyperventilation, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Mean Velocity (Short-term memory test)
With short-term memory test, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Mean Velocity (Vocabulary problem)
With solving vocabulary problems, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Mean Velocity (Math problem.)
With solving math problems, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Basal)
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Hypoventilation)
By performing Hypoventilation, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Hyperventilation)
By performing Hyperventilation, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Short-term memory test)
With short-term memory test, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Vocabulary problems)
With solving vocabulary problems, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Peak systolic velocity (Math problems)
With solving math problems, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Basal)
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Hypoventilation)
By performing Hypoventilation, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Hyperventilation)
By performing Hyperventilation, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Short-term memory test)
With short-term memory test, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Vocabulary problems)
With solving vocabulary problems, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Vend-diastolic velocity (Math problems)
With solving math problems, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Secondary outcomes (6)
Changes in Heart Rate (Basal)
Changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Heart Rate (Hypoventilation)
By performing Hypoventilation, changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Heart Rate (Hyperventilation)
By performing Hyperventilation, changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Heart Rate (Short-term memory test)
With short-term memory test, changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Heart Rate (Vocabulary problems)
With solving vocabulary problems, changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Changes in Heart Rate (Math problems)
With solving math problems, changes in Heart Rate, measure in bpm from baseline to 30 minutes after caffeine ingestion.
Measured: 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2023
- Study start1 May 2021
- Primary completion1 Jun 2021
- Study completion1 Jun 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Cardiovascular SystemStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Randomised
- Intervention model
- Parallel groups
- Model description
- All subjects were submitted to 2 evaluation moments: the first baseline moment and the second moment, 30 minutes after caffeine ingestion, which constitutes the time required for caffeine absorption. In each of the 2 moments, they performed 30 seconds of continuous breathing (hypoventilation), followed by 30 seconds of continuous rapid breathing (hyperventilation). VMCA measurements were stabilized between these tests. The study started with apnea testing because VMCA requires less time to return to baseline levels after hypoventilation than after hyperventilation. When VMCA measurements were stable, a 30-second baseline period was followed by three 30-second cognitive tasks, with a 1-minute break between activities: short-term memory test; solve a vocabulary problem; and solving a math problem. Three versions of each cognitive task were used for the three conditions. The procedure was completed with a final rest period of 60 seconds.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 45 participants (actual)
Sponsor and investigators
- Lead sponsor
- Escola Superior de Tecnologia da Saúde de Coimbra
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Helder Santos, PhD, Escola Superior de Tecnologia da Saúde de Coimbra
- Investigators
- Hélder Santos, PhD, Principal investigator, Polytechnic Institute of Coimbra - Coimbra Health School
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05866848
- Sponsor's protocol ID
- CCBF
- Status last verified
- May 2023
- First submitted
- 6 Apr 2023
- Last updated
- 19 May 2023
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Gaspar C, Rocha C, Balteiro J, Santos H. Effects of caffeine on cerebral blood flow. Nutrition. 2024 Jan;117:112217. doi: 10.1016/j.nut.2023.112217. Epub 2023 Sep 6.
PubMed 37826937
Study at a glance
From the registry record, last updated by the sponsor on 19 May 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Caffeine on Cerebral Blood Flow in Clinically Healthy Young People
- ClinicalTrials.gov ID
- NCT05866848
- Acronym / sponsor ID
- CCBF
- Conditions
- Cardiovascular System
- Keywords
- Transcranial Doppler ultrasonography, Middle Cerebral Artery, functional tests, cognitive activities, caffeine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 45 participants (actual)
- Lead sponsor
- Escola Superior de Tecnologia da Saúde de CoimbraUniversity, hospital or other
- Study start
- 1 May 2021 (actual)
- Primary completion
- 1 Jun 2021 (actual)
- Study completion
- 1 Jun 2021 (actual)
- First posted
- 19 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to evaluate in clinically healthy young people if:
- after caffeine ingestion, there are variations in blood velocity of the middle cerebral arteries (VMCA),
- this variation is dependent on the administered dose.
Transcranial Doppler ultrasonography was used to record blood VMCA in three groups of 15 clinically healthy young adults each - no caffeine, low caffeine (45 mg) and high caffeine group (120 mg). Transcranial Doppler ultrasonography provided simultaneous bilateral VMCA measurements while subjects performed functional tests (hyperventilation and hypoventilation orders) and three cognitive activities (Test 1, short-term remembering, Test 2, solving a vocabulary problem, and Test 3, solving a math problem) each in 31-second tests with 1-minute rest between them. Participants were assessed before and 30 minutes after caffeine ingestion.
Detailed description
Were used in the study, Capsules dosed with 45mg and 120 mg of anhydrous caffeine and flour capsules as a placebo. In the preparation of the capsules, a semi-automatic capsulator No. 0 (Capsunorm® by Tecnyfarma®) were used, colorless hard gelatin capsules No. 0 by Acopharma® and anhydrous caffeine (Biochem®, C.A.S. 58-08-2).
Viasys Sonara transcranial Doppler unit and a 2 MHz probe were used to sample the middle cerebral artery at depths of 60 millimeters, using emission doppler pulsed performing spectral analysis in real time. Two probes (bilaterally) of 2MHz were placed at a depth between 55 and 60 mm, thus making it possible to analyse both middle cerebral arteries simultaneously.
Each participant was asked not to ingest caffeine and exercise vigorously for at least 12 hours before the assessment. In the case of smokers, they were also asked not to smoke for at least 2 hours before the evaluation. The laboratory had medium luminosity, silent and controlled temperature (23º/24ºC). To avoid inter-observer errors, all examinations were performed by the same investigator who was not aware of what dose was/had been administered to the participant.
Subjects were tested while seated in a reclining chair located in a dimly lit, sound-attenuated room and performed the activities with their eyes closed.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- All subjects were submitted to 2 evaluation moments: the first baseline moment and the second moment, 30 minutes after caffeine ingestion, which constitutes the time required for caffeine absorption. In each of the 2 moments, they performed 30 seconds of continuous breathing (hypoventilation), followed by 30 seconds of continuous rapid breathing (hyperventilation). VMCA measurements were stabilized between these tests. The study started with apnea testing because VMCA requires less time to return to baseline levels after hypoventilation than after hyperventilation. When VMCA measurements were stable, a 30-second baseline period was followed by three 30-second cognitive tasks, with a 1-minute break between activities: short-term memory test; solve a vocabulary problem; and solving a math problem. Three versions of each cognitive task were used for the three conditions. The procedure was completed with a final rest period of 60 seconds.
| Arm | Type | Receives |
|---|---|---|
| No caffeine | Placebo comparator | Other: PlaceboThe control group took flour capsules. |
| Low caffeine | Experimental | Other: Anhydrous caffeine (45mg)Group with relatively small amount of caffeine (45 mg) administered. |
| High caffeine | Experimental | Other: Anhydrous caffeine (120mg)Group with greater amount of caffeine (120 mg) administered. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- clinically healthy young people
Key exclusion criteria (1 listed)
- Individuals with hypertension, high cholesterol, diabetes, arrhythmias, carotid sinus syndrome, severe carotid stenosis and who were in an unstable clinical situation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PlaceboFlour capsules as a placebo. | Other | No caffeine |
| Anhydrous caffeine (45mg)Capsules dosed with 45mg of anhydrous caffeine. | Other | Low caffeine |
| Anhydrous caffeine (120mg)Capsules dosed with 120mg of anhydrous caffeine. | Other | High caffeine |
Primary outcome
Changes in Mean Velocity (Basal)
Time frame: 30 minutes
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Mean Velocity (Hypoventilation)
Time frame: 30 minutes
By performing Hypoventilation, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Mean Velocity (Hyperventilation)
Time frame: 30 minutes
By performing Hyperventilation, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Mean Velocity (Short-term memory test)
Time frame: 30 minutes
With short-term memory test, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Mean Velocity (Vocabulary problem)
Time frame: 30 minutes
With solving vocabulary problems, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Mean Velocity (Math problem.)
Time frame: 30 minutes
With solving math problems, changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Basal)
Time frame: 30 minutes
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Hypoventilation)
Time frame: 30 minutes
By performing Hypoventilation, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Hyperventilation)
Time frame: 30 minutes
By performing Hyperventilation, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Short-term memory test)
Time frame: 30 minutes
With short-term memory test, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Vocabulary problems)
Time frame: 30 minutes
With solving vocabulary problems, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Peak systolic velocity (Math problems)
Time frame: 30 minutes
With solving math problems, changes in Peak systolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Basal)
Time frame: 30 minutes
Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Hypoventilation)
Time frame: 30 minutes
By performing Hypoventilation, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Hyperventilation)
Time frame: 30 minutes
By performing Hyperventilation, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Short-term memory test)
Time frame: 30 minutes
With short-term memory test, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Vocabulary problems)
Time frame: 30 minutes
With solving vocabulary problems, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
Changes in Vend-diastolic velocity (Math problems)
Time frame: 30 minutes
With solving math problems, changes in Vend-diastolic velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.
6 secondary outcomes
Changes in Heart Rate (Basal)
Time frame: 30 minutes
Changes in Heart Rate (Hypoventilation)
Time frame: 30 minutes
Changes in Heart Rate (Hyperventilation)
Time frame: 30 minutes
Changes in Heart Rate (Short-term memory test)
Time frame: 30 minutes
Changes in Heart Rate (Vocabulary problems)
Time frame: 30 minutes
Changes in Heart Rate (Math problems)
Time frame: 30 minutes
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 May 2023.
- Derived from this study: PubMed 37826937Gaspar C, Rocha C, Balteiro J, Santos H. Effects of caffeine on cerebral blood flow. Nutrition. 2024 Jan;117:112217. doi: 10.1016/j.nut.2023.112217. Epub 2023 Sep 6.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Hélder Santos, PhD principal investigator
Polytechnic Institute of Coimbra - Coimbra Health School
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Anhydrous caffeine (45mg) and Anhydrous caffeine (120mg) in people with Cardiovascular System, run by Escola Superior de Tecnologia da Saúde de Coimbra at 1 site in Portugal.
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 1 inclusion and 1 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 19 May 2023. 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 Portugal. 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?
Changes in Mean Velocity (Basal) (time frame: 30 minutes). The study lists 18 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 NCT05866848, which also lists 1 linked publication.
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 19 May 2023.