NCT05866848

Brief 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. 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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
45

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started May 2021

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

May 1, 2021

Completed
1 month until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 1, 2021

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2021

Completed
1.8 years until next milestone

First Submitted

Initial submission to the registry

April 6, 2023

Completed
1 month until next milestone

First Posted

Study publicly available on registry

May 19, 2023

Completed
Last Updated

May 19, 2023

Status Verified

May 1, 2023

Enrollment Period

1 month

First QC Date

April 6, 2023

Last Update Submit

May 10, 2023

Conditions

Cardiovascular System

Keywords

Transcranial Doppler ultrasonographyMiddle Cerebral Arteryfunctional testscognitive activitiescaffeine

Outcome Measures

Primary Outcomes (18)

  • Changes in Mean Velocity (Basal)

    Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.

    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.

    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.

    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.

    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.

    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.

    30 minutes

  • Changes in Peak systolic velocity (Basal)

    Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.

    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.

    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.

    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.

    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.

    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.

    30 minutes

  • Changes in Vend-diastolic velocity (Basal)

    Changes in Mean Velocity, measure in m/s from baseline to 30 minutes after caffeine ingestion.

    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.

    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.

    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.

    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.

    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.

    30 minutes

Secondary Outcomes (6)

  • Changes in Heart Rate (Basal)

    30 minutes

  • Changes in Heart Rate (Hypoventilation)

    30 minutes

  • Changes in Heart Rate (Hyperventilation)

    30 minutes

  • Changes in Heart Rate (Short-term memory test)

    30 minutes

  • Changes in Heart Rate (Vocabulary problems)

    30 minutes

  • +1 more secondary outcomes

Study Arms (3)

No caffeine

PLACEBO COMPARATOR

The control group took flour capsules.

Other: Placebo

Low caffeine

EXPERIMENTAL

Group with relatively small amount of caffeine (45 mg) administered.

Other: Anhydrous caffeine (45mg)

High caffeine

EXPERIMENTAL

Group with greater amount of caffeine (120 mg) administered.

Other: Anhydrous caffeine (120mg)

Interventions

PlaceboOTHER

Flour capsules as a placebo.

No caffeine
Anhydrous caffeine (45mg)OTHER

Capsules dosed with 45mg of anhydrous caffeine.

Low caffeine
Anhydrous caffeine (120mg)OTHER

Capsules dosed with 120mg of anhydrous caffeine.

High caffeine

Eligibility Criteria

Age18 Years - 30 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • clinically healthy young people

You may not qualify if:

  • Individuals with hypertension, high cholesterol, diabetes, arrhythmias, carotid sinus syndrome, severe carotid stenosis and who were in an unstable clinical situation.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Coimbra Health School

Coimbra, 3046-854, Portugal

Location

Related Publications (1)

  • 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.

    PMID: 37826937DERIVED

Study Officials

  • Hélder Santos, PhD

    Polytechnic Institute of Coimbra - Coimbra Health School

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Masking Details
Three groups were randomly constituted, with 15 young people each: control group without caffeine, group with relatively small amount of caffeine (45 mg) administered and group with greater amount of caffeine (120 mg). Participants were not aware to which group they belong.
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Model Details: 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.
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

April 6, 2023

First Posted

May 19, 2023

Study Start

May 1, 2021

Primary Completion

June 1, 2021

Study Completion

June 1, 2021

Last Updated

May 19, 2023

Record last verified: 2023-05

Locations

PT(1)