Effects of Exercise and Energy Balance on 24-hour Blood Glucose Control

Study Overview
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Brief Summary
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The study team will assess free-living 24h glucose control using continuous glucose monitors (CGM) over an 88h period on two separate occasions. Importantly, standardized meals will be provided and will be consumed at specific times each day of the CGM measurement period. These meals will be identical on day 1 and day 3 of measurement. Each subject will complete two CGM periods, which will be identical except for the calorie and macronutrient content of the post-exercise dinner. In addition, during trial 1, two CGM's will be worn, while only 1 CGM will be worn on trial 2.

Detailed Description
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Subjects will be instructed to exercise exactly 2 days before each experimental trial period, and then abstain from exercise other than the exercise session on Day 2 of the trial period until after the trial period is complete. Subjects will arrive to the Substrate Metabolism Laboratory at approximately 4pm on Day 0 of each trial. For trial 1, two CGM devices will be placed on either side of the abdomen, near the belly button. For trial 2, only one CGM device will be placed on one side of the abdomen. On Day 1 of both trials, participants will go about their normal daily activities (other than planned exercise) while eating provided meals at designated time points. This day will serve as the non-exercise control day. On Day 2, subjects will return to the laboratory to exercise on the bike for  1h at a moderate exercise intensity (approximately 65% of their measured VO2peak) to expend 350 kilocalories. During trial 1 only, subjects will use the mouthpiece and nose clip (which will allow all of their expired air to pass through the metabolic cart for analysis of oxygen consumption and carbon dioxide production) for  5 min at the beginning, middle and toward the end of exercise to verify they are exercising at 65% of VO2peak. This will also allow the study team to accurately measure energy expenditure (kcal) during exercise. On trial 2, subjects will perform the exact same exercise protocol, but the mouthpiece and nose clip will not be required. One hour after the exercise session, participants will eat their standardized dinner. Importantly, the caloric content of this meal will differ between the two trials (+/- 350kcal), and this will be the only difference between the two study trial periods. On Day 3, participants will go about their normal daily activities (other than planned exercise) while eating the provided meals at designated time points. This day will serve as the post-exercise day. On Day 4, participants will return to the laboratory at approximately 8am for removal of the CGM device(s).

Official Title
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Effects of Exercise and Energy Balance on 24-hour Blood Glucose Control

Conditions
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Metabolic Disease, Adipose Tissue

Intervention / Treatment
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* Behavioral: Trial 2 Exercise
* Behavioral: Trial 1 Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion criteria Age: 18-40 Body Mass Index: 20-30 kg/m2 Exclusion criteria Pregnant or lactating Evidence/history of cardiovascular or metabolic disease Medications known to affect glucose metabolism

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Trial 1<br>Subjects will have two CGM devices placed on either side of the abdomen, near the belly button. Trial 1 Exercise - subjects will use a mouthpiece and nose clip (which will allow all of their expired air to pass through the metabolic cart for analysis of oxygen consumption and carbon dioxide production) for  5 min at the beginning, middle and toward the end of exercise to verify they are exercising at 65% of VO2peak. This will allow us to accurately measure energy expenditure (kcal) during exercise. One hour after the exercise session, participants will eat a standardized dinner which includes the energy expended from their exercise session (+ 350 kcal). | Behavioral: Trial 1 Exercise<br>* During the exercise session, subjects will use a mouthpiece and nose clip (which will allow all of their expired air to pass through the metabolic cart for analysis of oxygen consumption and carbon dioxide production) for  5 min at the beginning, middle and toward the end of exercise to verify they are exercising at 65% of VO2peak. This will allow us to accurately measure energy expenditure (kcal) during exercise. One hour after the exercise session, participants will eat a standardized dinner which includes the energy expended from their exercise session (+ 350 kcal).<br>|
| Experimental: Trial 2<br>Subjects will have one CGM device placed on one side of the abdomen. Trial 2 Exercise - subjects will exercise at 65% of VO2peak. One hour after the exercise session, participants will eat a standardized dinner which will NOT include the energy expended from their exercise session (- 350 kcal). | Behavioral: Trial 2 Exercise<br>* During the exercise session, subjects will exercise at 65% of VO2peak. One hour after the exercise session, participants will eat a standardized dinner which will NOT include the energy expended from their exercise session (- 350 kcal).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Post-prandial glucose values | Average Post-prandial glucose values (1 hour, 2 hour, and 3 hours) will be measured | 1 week | 
| area under curve Post-prandial glucose values (1 hour, 2 hour, and 3 hours) | 1 hour, 2 hour, and 3 hours time-point for Post-prandial glucose values will be measured | 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 hour glycemic response | Average 24 hour glycemic response will be measured | 1 day | 
| Area under curve - 24 hour glycemic response | 24 hour glycemic response area under curve will be measured | 1 day | 
| CGM Sensor Variability when measured simultaneously | coefficient variation of blood glucose between the 2 CGM devices placed during trial 1 | 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise