CNS Oxygen Toxicity, Ketogenic Diet
Conditions
Brief summary
The purpose of this research study is to understand the effect of nutritional ketosis on CNS oxygen toxicity in undersea divers. The investigators hope this will provide a starting point to develop methods for improving the safety of Navy divers, warfighters and submariners.
Detailed description
Participants in the study will undergo a physical exam and testing as well as training on cognitive testing software as part of the screening process. Eligible subjects will be assigned a normal diet or a ketogenic diet (a diet high in fat/protein and low in carbohydrates) for three days before testing. Subjects will be immersed in water to the shoulders, inside a hyperbaric (high pressure) chamber while breathing 100% oxygen at increased atmospheric pressure, and doing cycling exercise. Testing on the cognitive software, as well as blood sampling and physical monitoring will be done while in the chamber. All tests and procedures will be completed again at least one week later with the diet not assigned for the first session.
Interventions
DIETARY_SUPPLEMENTKetogenic Diet
Eat a ketogenic diet (low carbohydrate, high fat diet) for 72 hrs prior to the experiment and consume a dietary ketone supplement 60 minutes before the experiment.
Sponsors
United States Department of Defense
Duke University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
Neither the investigator nor the outcomes assessor will no the ketone level of the participant during either arm of the study
Intervention model description
Each subject will randomize to one of two arms and will crossover to the other arm at least one week later.
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Males & females between 18 and 50 years old * Able to pedal a bicycle ergometer continuously for 15 minutes * Non-smoker * No history of cardiovascular disease, including coronary artery disease, valvular disease, cardiomyopathy or hypertension. * No history of lung disease
Exclusion criteria
* Prolonged QTc on initial ECG * Currently pregnant or attempting to become pregnant. * Have a history of: 1. Smoking 2. Coronary artery disease 3. Hypertension 4. Seizures 5. Exercise intolerance 6. Psychiatric disorder 7. Previous pneumothorax or pneumomediastinum 8. Hypo or hyperglycemia 9. Diabetes * Regularly take any medications which may alter heart rate, blood pressure, neurotransmitter function, mood or affect.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to First Manifestations of CNS Oxygen Toxicity | 2 hrs | Time to the first manifestation of CNS Oxygen Toxicity: visual or hearing changes, nausea, twitching, irritability, dizziness, convulsions or change consistent with possible CNS Oxygen Toxicity. |
Countries
United States
Outcome results
None listed