Thermic Effect of Feeding in Cystic Fibrosis

Study Overview
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Brief Summary
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The investigators propose to assess the contributions of the thermic effect of food intake (TEF), which is the amount of energy expended to digest food, to overall energy expenditure in Cystic Fibrosis (CF).

Detailed Description
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Total energy expenditure (TEE) is comprised of the following components: resting energy expenditure (REE), thermic effect of food intake (TEF), adaptive thermogenesis (AT). The thermic effect of food is the amount of energy expended to digest food, and can be affected by factors such as protein / fat / carbohydrate contents of meals or the amount of time over which a meal is consumed. The investigators propose to assess the contributions of the thermic effect of food intake (TEF), which is the amount of energy expended to digest food, to overall energy expenditure in CF. Participants will be assigned to either a high fat liquid meal or a high protein liquid meal and assessed for components of energy expenditure in the whole room indirect calorimeter (metabolic chamber); participants will then be crossed over to the alternate liquid meal type, and differences in resting and total energy expenditure and the thermic effect of food will be assessed between the two types of meals.

Official Title
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Thermic Effect of Feeding in Cystic Fibrosis

Conditions
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Cystic Fibrosis

Intervention / Treatment
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* Dietary Supplement: Boost VHC
* Dietary Supplement: Ensure High Protein


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: confirmed diagnosis of cystic fibrosis by Cystic Fibrosis Foundation-established criteria being followed at the VCU (Virginia Commonwealth University) Adult Cystic Fibrosis Center pulmonary and overall health status at baseline as assessed by pulmonary function testing and screening labs (complete blood count, liver enzymes, cholesterol, HgA1c). Criteria for baseline status are established for each individual patient as part of routine CF pulmonary care. ability to understand the study procedures and to comply with them for the entire length of the study Exclusion Criteria: experiencing any signs or symptoms consistent with a pulmonary exacerbation (a decline in pulmonary function testing from baseline, recorded as part of routine CF care) undergoing treatment for a pulmonary exacerbation with a change in antibiotics or steroids from their baseline medications tobacco users pregnancy

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High fat<br>Boost VHC (Very High Calorie), Nestle, 8 ounce can | Dietary Supplement: Boost VHC<br>* 8 ounce can liquid meal, calories 530kcal, Carbohydrate 46g, Protein 22g, Fat 30g<br>|
| Experimental: High protein<br>Ensure High Protein 8 ounce can | Dietary Supplement: Ensure High Protein<br>* 8 ounce can liquid meal, calories 160kcal, Carbohydrate 13g, Protein 16g, Fat 2g<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Energy Expenditure | The changes in energy expenditure measured in kcal (resting energy expenditure prior to feeding, and thermic effect of food after meal administration) will be recorded in the metabolic chamber. | 16 hours after entry into metabolic chamber | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| glucose | blood glucose (mg/dL) measured with continuous glucose sensor and fasting venous sample at end of study visit | 16 hours after entry into metabolic chamber | 
| insulin | fasting insulin level (mIU/mL) measured at end of overnight visit | 16 hours after entry into metabolic chamber | 
| Leptin | fasting leptin level (ng/mL) measured at end of overnight visit | 16 hours after entry into metabolic chamber | 
| Ghrelin | fasting grehlin levels (pg/mL) measured at end of overnight visit | 16 hours after entry into metabolic chamber |