PET Study of Cerebral Metabolism of 11C-acetoacetate and 18F-FDG in Patients Under Moderate Ketosis

Study Overview
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Brief Summary
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Regional brain glucose hypometabolism occurs during aging and may contribute to the onset of aging-related cognitive impairment in humans. Ketones are the main alternative energy substrate to glucose for the brain. Several studies show that brain ketone uptake and metabolism are unaltered in cognitively-normal older persons and in Alzheimer's disease (AD). Nutritional ketosis is reported to have a positive impact on cognitive performances in mild cognitive impairment and AD. Nevertheless, changes in regional brain glucose and ketone uptake in adults are poorly understood during diet-induced experimental ketosis. The investigators hypothesis was that during diet-induced ketosis, brain ketone uptake would be directly correlated with the elevation of blood ketone levels and inversely correlated to brain glucose uptake.

Official Title
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PET Study of Cerebral Metabolism of 11C-acetoacetate and 18F-FDG in Patients Under Moderate Ketosis

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Pre-KD
* Dietary Supplement: Post-KD


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adults No signs of cognitive impairment Exclusion Criteria: Not within the age limits Pregnancy or breast feeding Incapacity to withstand a supine position for 40 min Non lacunar infarction Known psychiatric history of schizophrenia, psychotic disorders, major affective disorders (bipolar disorder and major depression <5 years), panic disorder, obsessive compulsive disorders and other conditions that may affect memory Epilepsy, brain trauma with loss of consciousness, subarachnoid hemorrhage History of alcool and/or substances abuse (excessive alcool consumption ≥10 drinks/weeks) Parkinson disease Down syndrome Inflammatory disease Abnormal blood pressure, liver or kidney function, blood count Dyslipidemia, hypothyroidism, osteoporosis Presence of a metal object in the body

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Ten participants received a very high fat ketogenic diet (KD) (4.5:1; lipid:protein plus carbohydrates) for four days.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ketogenic diet<br>Pre/Post TEP study with a 4 days ketogenic diet (KD). Interventions 1: Pre-KD = Participants did a TEP before starting the 4-day diet Intervention 2: Post-KD = Participants did a TEP after completing the 4-day diet | Dietary Supplement: Pre-KD<br>* Before starting 4 days of 4:1 (lipids:protein/carbohydrates) ketogenic diet<br>Dietary Supplement: Post-KD<br>* After 4 days of 4:1 (lipids:protein/carbohydrates) ketogenic diet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean in Cerebral Metabolic Rate of Acetoacetate Before or After 4 Days of Ketogenic Diet |  | At baseline (approximatively 1 month before the onset of the diet) and right after a 4 days ketogenic diet | 
| Mean in Cerebral Metabolic Rate of Glucose Before or After 4 Days of Ketogenic Diet |  | At baseline (approximatively 1 month before the onset of the diet) and right after a 4 days ketogenic diet | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ketones, Brain metabolism, Ketogenic diet, TEP scan