Influence of Caffeine on Psychomotor Vigilance and Carbon Dioxide Tolerance During Graded Hypercapnia

NCT06636825 | Completed

• 1 other identifier: 23-05
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this randomized, double-blind, placebo-controlled crossover trial is to determine the effects of caffeine vs. placebo on psychomotor vigilance and carbon dioxide tolerance during graded hypercapnia.

Conditions

Hypercapnia

Keywords

Caffeine; Carbon dioxide; Cognitive Function

Outcome Measures

Primary Outcomes (3)

• End-tidal CO2

  End-tidal CO2 (mmHg)

  60 minutes

• PVT Performance

  Psychomotor vigilance (mean reaction time in s)

  60 minutes

• Carbon dioxide tolerance

  Time spent in graded hypercapnia protocol (minutes)

  60 minutes

Secondary Outcomes (18)

• Ventilation

  60 minutes

• Respiratory Rate

  60 minutes

• Tidal volume

  60 minutes

• Oxygen Consumption

  60 minutes

• Carbon dioxide release

  60 minutes

Study Arms (2)

Placebo

PLACEBO COMPARATOR

Placebo (microcrystalline cellulose) capsule taken in a single dose 1 hour prior to graded hypercapnia

Other: Graded hypercapnia; Drug: Placebo

Experimental

EXPERIMENTAL

400 mg caffeine capsule taken in a single dose 1 hour prior to graded hypercapnia

Other: Graded hypercapnia; Drug: Caffeine

Interventions

Graded hypercapnia OTHER

Volunteers breathe 0%, 2%, 4%, 6%, and 8% CO2 (with 21% O2, balance nitrogen) for 12 minutes each

Experimental; Placebo

Caffeine DRUG

400 mg caffeine capsule taken in a single dose 1 hour prior to graded hypercapnia

Experimental

Placebo DRUG

Placebo (microcrystalline cellulose) capsule taken in a single dose 1 hour prior to graded hypercapnia

Placebo

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male or female, age 18-45
• Body mass index 18.5-30.0 kg m-2
• Body mass 50-100 kg
• In good health as determined by the Office of Medical Support \& Oversight (OMSO) General Medical Clearance
• Perform exercise at least 2 times per week
• Willing to abstain from exercise and alcoholic beverages for 24 hours before each study visit.
• Willing to abstain from caffeine for 12 hours prior to all study visits
• Willing to abstain from caffeine for 12 hours after visits 3 and 4
• Willing to remain fasted (no food or fluid other than water) from lights out until after arrival at the laboratory the following morning on each study day (\~10 hours)
• Have supervisor approval if permanent party military or a federal employee at U.S. Army Natick Soldier System Center

You may not qualify if:

• Females who are pregnant or planning to become pregnant during the study
• Females who are surgically sterile
• History of severe adverse reaction to caffeine (e.g., headache, dizziness, diarrhea, insomnia)
• Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by OMSO \& PI)
• Abnormal blood count (For example: hemoglobin (Hb) outside of the typical normal values reported by LabCorp in accordance with OMSO (Normal \[Hb\] Males = 12.6-17.7 g/dL; Females = 11.1-15.9 g/dL) or hematocrit (Hct) outside of the normal ranges (Normal Hct Males = 37.5-51.0%; Females = 34.0-46.6%) levels, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits)
• Any history of pulmonary or cardiovascular disease
• Current diagnosis of asthma (childhood asthma with no recurrence in the last 5 years ok)
• Smokers or nicotine users (unless have quit \>1 month prior)
• Current or recent respiratory tract or sinus infections (\< 1 month prior)
• Current diagnosis of migraine or recurrent headaches (previous diagnosis with no recurrence in the last 5 years ok)
• Any history of seizures
• Any history of panic disorder
• Blood donation in the previous 8 weeks
• Positive Covid-19 test within the last month (based on self-report)

Sponsors & Collaborators

• United States Army Research Institute of Environmental Medicine: lead

Study Sites (1)

US Army Research Institute of Environmental Medicine

Natick, Massachusetts, 01760, United States

Location

MeSH Terms

Conditions

Hypercapnia

Interventions

Caffeine

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Xanthines; Alkaloids; Heterocyclic Compounds; Purinones; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: FED
• Responsible Party: SPONSOR

Model Details: Randomized, double-blind, placebo-controlled crossover trial

Study Record Dates

• First Submitted: October 4, 2024
• First Posted: October 15, 2024
• Study Start: November 9, 2023
• Primary Completion: September 17, 2024
• Study Completion: September 17, 2024
• Last Updated: October 15, 2024

Record last verified: 2024-10

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)