Breaking up Sedentary Time to Improve Glucose Control in a Population at Risk for Developing Type 2 Diabetes (BURST2D)
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ClinicalTrials.gov Identifier: NCT05041491 |
Recruitment Status :
Recruiting
First Posted : September 13, 2021
Last Update Posted : March 16, 2023
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Condition or disease | Intervention/treatment | Phase |
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Pre-diabetes | Behavioral: BREAK Behavioral: ONE | Early Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 66 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Participants will be randomized to either the BREAK condition (5-min bouts of brisk walking performed hourly for 9 hours/day, 5 days/wk) or the ONE condition (45-min of brisk walking performed as a single continuous bout, 5 days/wk) for 3 months. Participants will complete all study visits in only one group. |
Masking: | Single (Outcomes Assessor) |
Masking Description: | A study research assistant that is not involved in the study participants' allocation process will create opaque, sealed envelopes with allocation sequences based on the randomization table created by the study statistician. The assignment of intervention to study participants will be based on the study allocation sequence generated by the statistician and the study team will enroll study participants and assign them to the interventions. The study team will be blinded until study participants' allocation (the day before visit G). After this, the study team will not be blinded to study participants' allocation as they will be responsible for assigning study participants, and for applying and monitoring the interventions. The study statistician will always be blinded. |
Primary Purpose: | Prevention |
Official Title: | Breaking up Sedentary Time to Improve Glucose Control in a Population at Risk for Developing Type 2 Diabetes |
Actual Study Start Date : | November 30, 2021 |
Estimated Primary Completion Date : | December 31, 2024 |
Estimated Study Completion Date : | October 15, 2025 |

Arm | Intervention/treatment |
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Experimental: BREAK Intervention
Participants in the BREAK condition will perform 5-minute bouts of brisk walking hourly for 9 hours/day, 5 days/week for 3 months.
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Behavioral: BREAK
The BREAK intervention is a physical activity regimen. |
Active Comparator: ONE Intervention
Participants in the ONE condition will perform 45 minutes of brisk walking as a single continuous bout, 5 days/week for 3 months.
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Behavioral: ONE
The ONE intervention is a physical activity regimen. |
- Glycemia [ Time Frame: Glucose concentration in mg/dl, measured at fasting, during a 2 hour OGTT and after ]Plasma glucose concentration in mg/dL measured before and 30, 60, 90 and 120 min after an oral glucose tolerance test (OGTT, 75g glucose).
- Insulinemia [ Time Frame: Plasma insulin concentration in mUI/mL, measured at fasting, during a 2 hour OGTT and after ]Plasma insulin concentration in mUI/mL measured before and 30, 60, 90 and 120 min after an oral glucose tolerance test (OGTT, 75g glucose).
- Mean interstitial glucose concentration [ Time Frame: Before and after 1 month and 3 months of intervention ]Mean interstitial glucose concentration measured continuously by a glucose monitor placed on the tricep for 24hours for 10 days.
- Daily glycemia variability [ Time Frame: Before and after 1 month and 3 months of intervention ]Standard deviation (SD) of interstitial glucose concentration measured continuously by a glucose monitor placed on the tricep 24hours throughout 10 days.
- Fasting A1c concentration [ Time Frame: Time Frame: Before and after 1 month and 3 months of intervention ]Fasting A1c concentration expressed in %
- Fasting fructosamine concentration [ Time Frame: Before and after 1 month and 3 months of intervention ]Fasting fructosamine concentration in umol/L
- 12-hour exogenous glucose oxidation [ Time Frame: Before and after 1 month of intervention ]Rates of 13C recovery (% of the dose) in expired CO2 following the ingestion of U-13C-glucose in both breakfast and lunch meals.
- 12-hour endogenous glucose oxidation [ Time Frame: Before and after 1 month of intervention ]Rates of D2 recovery (% of the dose) in expired urines following the infusion of (2,2H2) glucose.
- 12 hour CO2 production [ Time Frame: Before and after 1 month of intervention ]CO2 production measured by indirect calorimetry (ParvoMedics TrueOne 2400, Salt Lake City) for 20 minutes every hour from 0800h to 1800h.
- 12 hour O2 production [ Time Frame: Before and after 1 month of intervention ]O2 production measured by indirect calorimetry (ParvoMedics TrueOne 2400, Salt Lake City) for 20 minutes every hour from 0800h to 1800h.
- 12 Urine excretion [ Time Frame: Before and after 1 month of intervention ]Urine will be measured every hour from 0730h to 1830h
- Glucose kinetics [ Time Frame: Before and after 1 month of intervention ]Steele's equation for non-steady-state will be used to compute RaT and RaE, as well as the rates of disappearance (RdT and RdE) from the percentage of [6,6-2H2]glucose6 and of 13C-glucose in plasma glucose61. EGP will be computed as RaT-RaE. Nonoxidative glucose disposal (NOGD) will be calculated by subtracting total carbohydrate oxidation from (RdT + RdE). Plasma glucose utilization will be assumed to be equivalent to RdT as has been confirmed previously. Muscle glycogen utilization during the active period will be calculated as total carbohydrate utilization during exercise minus plasma glucose utilization during exercise.
- Fasting and postprandial glucose [ Time Frame: Before and after 1 month of intervention ]Fasting and postprandial glucose in mg/dl measured in response to standard lunch
- Fasting and postprandial insulin [ Time Frame: Before and after 1 month of intervention ]Fasting and postprandial insulin in ml/iu measured in response to standard lunch
- Fasting and postprandial C-Peptide [ Time Frame: Before and after 1 month of intervention ]Fasting and postprandial C-peptide nmol/mL measured in response to standard lunch
- Fasting and postprandial glucagon [ Time Frame: Before and after 1 month of intervention ]Fasting and postprandial glucagon in pg/mL measured in response to standard lunch
- Fasting and postprandial catecholamines [ Time Frame: Before and after 1 month of intervention ]Fasting and postprandial catecholamines in pg/mL measured in response to standard lunch
- Skeletal muscle content of protein kinase B (Akt) (Aktser473/total) [ Time Frame: Before and after 1 month of intervention ]Vastus lateralis skeletal muscle biopsies will be collected from fasting participants by the Bergstrom technique. Biopsies will be used to measure protein kinase B (Akt) (Aktser473/total) using western blotting.
- Skeletal muscle content of ACC (ACCS79/ total) [ Time Frame: Before and after 1 month of intervention ]Vastus lateralis skeletal muscle biopsies will be collected from fasting participants by the Bergstrom technique. Biopsies will be used to measure ACC (ACCS79/ total) using western blotting.
- Skeletal muscle content of TBC1D4 (AS160/ total) [ Time Frame: Before and after 1 month of intervention ]Vastus lateralis skeletal muscle biopsies will be collected from fasting participants by the Bergstrom technique. Biopsies will be used to measure TBC1D4 (AS160/ total) using western blotting.
- Skeletal muscle content of COX4 [ Time Frame: Before and after 1 month of intervention ]Vastus lateralis skeletal muscle biopsies will be collected from fasting participants by the Bergstrom technique. Biopsies will be used to measure COX4 using western blotting.

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Ages Eligible for Study: | 18 Years to 64 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Male and female
- BMI of 18.5-40 kg/m2and weight stable over the previous 6 months.
- Age, 18-64 years old.
- Fasting glucose of 100-125 mg/dL or fasting HbA1c of 5.7-6.4%, or 2h OGTT blood glucose of 140-199mg/dL based on the American Diabetes Association criteria for pre-diabetes.
- Less than 150 minutes of moderate-to-vigorous physical activity (MVPA) per week and more than 6 hours of sitting time per day, as self-reported by the volunteers using the IPAQ.
- Less than 6500 of steps per day as measured by a pedometer over 5 days (at least 1 weekend day).
- Passing medical and physical screening, and analysis of blood and urine screening samples.
- Low-moderate caffeine use (<3 cups/day).
- Agree to refrain from any other structured exercise than the physical activity prescribed in each arm of the study.
- Agree to eat control diets for 3 days before and during the CTRC visits;
- Agree to refrain from taking any over-the-counter (including nonsteroidal anti-inflammatory drugs) or prescribed medication (apart from oral contraceptives) for 3 days prior to the inpatient CTRC visits;
- Agree to wear a Fitbit activity monitor and upload data on the website on a daily basis for the whole duration of the study.
- Agree to follow the physical activity interventions and to be randomly assigned to one of the two arms of the study.
- Agree to complete all the study procedures.
Exclusion Criteria:
- Pregnancy, breast-feeding or post-menopause for women.
- Being considered unsafe to participate as determined by the study physician.
- Ever having a history of systemic, psychiatric, neurological disease, or drug and alcohol abuse.
- History of cardiovascular disease, diabetes, uncontrolled hypertension, untreated thyroid, renal, hepatic diseases, dyslipidemia or any other medical condition affecting weight or lipid metabolism.
- Being positive for human immunodeficiency virus or hepatitis B or C.
- Taking medications affecting weight, triglycerides, energy intake/energy expenditure, or sleep in the last 3 months.
- Having abnormal blood chemistry and/or hematology as deemed significant by the study physician.
- Being a smoker or having been a smoker in the 3 months prior to their screening visit.
- Having donated over 400 mL of blood within 3 months (90 days) of screening for the study;
- Working night shifts or traveling across more than 2 time zones within 1 month of and throughout the study.
- Not completing the trial days of BREAK and ONE during the screening period to assess the willingness and ability of the participant to perform each of the interventions.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05041491
Contact: Patricia Smith, MS, RDN | 303.724.6821 | trish.smith@cuanschutz.edu | |
Contact: Audrey Bergouignan, PhD | 303.724.9026 | audrey.bergouignan@cuanschutz.edu |
United States, Colorado | |
University of Colorado Anschutz Medical Campus | Recruiting |
Aurora, Colorado, United States, 80045 | |
Principal Investigator: Audrey Bergouignan, PhD |
Principal Investigator: | Audrey Bergouignan, PhD | University of Colorado, Denver |
Responsible Party: | University of Colorado, Denver |
ClinicalTrials.gov Identifier: | NCT05041491 |
Other Study ID Numbers: |
20-1900 |
First Posted: | September 13, 2021 Key Record Dates |
Last Update Posted: | March 16, 2023 |
Last Verified: | March 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
sedentary behavior physical activity glucose control metabolism pre-diabetes |
Diabetes Mellitus Prediabetic State Glucose Intolerance Glucose Metabolism Disorders |
Metabolic Diseases Endocrine System Diseases Hyperglycemia |