The Brain Ketone Body Challenge Imaging Study will measure how the brain uses different fuels. To do this, radioactive compounds will be used during Positron Emission Tomography (PET) imaging. These compounds, called \[11C\]Acetoacetate (AcAc) and \[18F\] Fludeoxyglucose (FDG), are similar to the sugars and fats the brain already uses for fuel. These compounds safely allow researchers to see how the brain uses sugars and fats during PET scans.
After consuming a chilled 4 ounce shake which contains various dietary fats, cognitive testing and dual-tracer Positron Emission Tomography scan will be completed. At Visit 1, each participant will be randomized to Challenge A (low calorie Ensure®) or Challenge B (Ensure® plus ketone esters). At Visit 2, each participant will undergo the remaining challenge (A or B) prior to the second imaging session. Each visit is designed to be identical to the other and only vary the dose of ketone esters. Randomization to either Challenge at Visit 1 will ensure that test/re-test learning effects are equally distributed between the challenge groups. This study consists of two visits that will take place over a two week period.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Challenge A will include a low calorie Ensure shake for the participant to drink with no ketone esters (KE).
Challenge B will include an Ensure shake for the participant to drink with deltaG ketone ester, which has generally recognized as safe (GRAS) supplement status .
Subject will drink the shake. Immediate recall memory testing. Subject will be placed in the scanner. Prior to PET acquisition, a low dose CT scan of the head will be obtained for attenuation correction. Patients will be injected with an intravenous bolus of up to 5-10mCi (370 MBq) (+/- 10%) of \[11C\]AcAc (over 2 minutes). This is the standard dose used in published clinical studies using \[11C\]AcAc. The PET acquisition will begin immediately after the tracer injection and last for a total of 30 minutes. 2 ml of blood will be sampled from the forearm vein at 3, 6, 8, 12, 20, and 28 minutes post \[11C\]AcAc tracer injection. This will be used for quantification of radiation estimates throughout the scan-period
Wake Forest School of Medicine
Winston-Salem, North Carolina, United States
Primary Outcome - Brain Ketone Utilization
The relative global uptake of \[11C\]AcAc during Challenge B compared to Challenge A. within each individual. How the brain uses sugars and fats for fuel and who is more likely to respond to dietary treatments.
Time frame: 2 weeks
Secondary Outcome - Memory Composite Score
How brain metabolism relates to the developement of memory problems. To look at memory score changes with ketone esters supplementation.
Time frame: 2 weeks
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