Apolipoprotein E (ApoE) and Metabolism

Study Overview
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Brief Summary
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Impaired metabolism and the gene apolipoprotein E (ApoE) are independent risk factors for cognitive impairment and dementia. In humans, there are three major versions of apoE (E): E2, E3, and E4. Some studies suggest that the different versions of apoE have varying effects on whole body and brain metabolism. The goal of this project is to better understand the relationship between apoE and metabolism. This will help investigators identify new targets for the prevention and treatment of cognitive decline and dementia.

Detailed Description
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The investigator hopes determine whether a participant's version of ApoE affects their metabolic rate at rest and during a cognitive challenge. To determine this, the investigator will measure basal (resting) metabolic rates using a technique called indirect calorimetry (IC). This is accomplished by wearing a loose-fitting face mask that measures oxygen intake and carbon dioxide output. To more accurately measure the amount of carbohydrates, fats and proteins that the body is metabolizing, participants will be asked to provide two urine samples (one at the beginning, and one at the end, of the study). To determine what version of ApoE the participant inherited, the investigator will conduct a genetic test on DNA isolated from the participant's blood.

Official Title
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APOE, Metabolism and Cognitive Function: An Assessment Via Indirect Calorimetry

Conditions
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Cognitive Function, Healthy

Intervention / Treatment
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* Other: Resting State Indirect Calorimetry
* Genetic: ApoE
* Diagnostic Test: Metabolism
* Other: Cognitive Challenge


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all races/ethnicities ages 18-65 cognitively normal good health Exclusion Criteria: pregnant or breastfeeding. have a bleeding disorder, have a history of stroke, seizures, Parkinson's disease, history of head injury with loss of consciousness, or other dementing disorder. have a history of alcoholism or drug abuse have a history of schizophrenia or currently suffer from bipolar disorder or major depression. have vision or hearing loss severe enough to interfere with cognitive testing

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Resting State Indirect Calorimetry|The investigator will measure the amount of oxygen participants breathe in and the amount of carbon dioxide they breathe out using a portable unit. Participants will be asked wearing a loose-fitting face mask that measures oxygen intake and carbon dioxide output.|
|Genetic: ApoE|The investigator will conduct a genetic test on DNA isolated from from the participants blood. Participants will be asked to provide about 2 tablespoons.|
|Diagnostic Test: Metabolism|To more accurately measure the amount of carbohydrates, fats and proteins that the participants bodies metabolize, participants will be asked to provide two urine samples (one at the beginning, and one at the end, of the study). The total amount of urine to be collected is approximately 4 teaspoons.|
|Other: Cognitive Challenge|Participants will be asked to follow simple instructions that are displayed on computer screen.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Indirect Calorimetry | Measure resting state respiratory quotient in cognitively normal participants with various ApoE genotypes | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory Quotient (RQ) | Measure RQ during a cognitive challenge in cognitively normal individuals with various ApoE genotypes | 4 hours |