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

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.

Study Overview

• Status: Completed
• Conditions: Metabolic Disease; Adipose Tissue
• Intervention / Treatment: Behavioral: Trial 1 Exercise; Behavioral: Trial 2 Exercise

Detailed Description

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).

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Trial 1; 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; 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).
Experimental: Trial 2; 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; 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).

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: University of Michigan

Study record dates

Study Major Dates

• Study Start (Actual): October 21, 2016
• Primary Completion (Actual): December 18, 2017
• Study Completion (Actual): December 18, 2017

Study Registration Dates

• First Submitted: November 13, 2017
• First Submitted That Met QC Criteria: November 20, 2017
• First Posted (Actual): November 22, 2017

Study Record Updates

• Last Update Posted (Actual): March 21, 2022
• Last Update Submitted That Met QC Criteria: March 18, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: Exercise
• Additional Relevant MeSH Terms: Metabolic Diseases
• Other Study ID Numbers: HUM00120520

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No