Fasted Exercise Training in Type 2 Diabetes

Study Overview
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Brief Summary
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This study compares aerobic exercise training performed before breakfast (i.e., in the fasted state) to similar training performed after breakfast in people with type 2 diabetes. Training will take place over 16 weeks.

Detailed Description
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People with type 2 diabetes (T2D) are encouraged to increase their physical activity (PA). Sometimes, increasing the amount of PA can be difficult. Therefore, simply recommending that individuals preform more exercise may not be effective in the long term. Recent short-term studies have started to explore how to maximize the effect of a single bout of exercise. For example, short term studies suggest that exercise performed after a meal may decrease blood sugars more than exercise performed after a meal. However, research in people without diabetes shows this may not be the best approach in the long-term. To date, no long-term study has compared the effects of exercise performed at different times of the day in people with T2D. This study will compare the effects of 16 weeks of regular exercise before breakfast compared to 16 weeks of regular exercise after breakfast. It is expected that exercise before breakfast (i.e., in the fasted state) will lead to greater improvements in blood sugar control, without the addition of more exercise. It could be very motivating for people with diabetes to know that they can get more benefits from exercise by changing when exercise is performed, rather than trying to increase the amount of exercise.

Official Title
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Exercise Training Before (Fasted) Versus After Breakfast in Type 2 Diabetes

Conditions
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Diabetes Mellitus, Type 2

Intervention / Treatment
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* Behavioral: Fasted Exercise
* Behavioral: Postprandial Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physician diagnosed type 2 diabetes Treated with diet and/or glucose lowering medications, but not insulin, for at least 6 months Sedentary (defined as reaching <150 minutes of aerobic exercise per week) A1C below 9.0% BMI ≥25 kg/m2 Central obesity as determined by waist circumference according to Diabetes Canada cutoffs: greater or equal to 94cm for males of European, Sub-Saharan African, Eastern Mediterranean and Middle Eastern descent, greater or equal to 90cm for males of South Asian, Chinese, Japanese, South and Central American descent, greater or equal to 80cm for females Able to walk for 50 minutes Exclusion Criteria: Smoking Consuming more than 10 alcoholic drinks/week History of stroke, myocardial infarction, or coronary artery disease Resting heart rate <100 bpm Resting blood pressure <160/100 mmHg Implantable device, such as a pacemaker, that would not be safe for Magnetic Resonance Imaging

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 75 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Fasted Exercise<br>Exercise training will be performed in the fasted state (i.e., before breakfast). | Behavioral: Fasted Exercise<br>* Exercise training will take place 3 times per week and will progress to 60 minutes at a workload corresponding to 80% of Ventilatory Threshold.<br>|
| Active Comparator: Postprandial Exercise<br>Exercise will be performed in the postprandial period (i.e., after breakfast) | Behavioral: Postprandial Exercise<br>* Exercise training will take place 3 times per week and will progress to 60 minutes at a workload corresponding to 80% of Ventilatory Threshold.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of HbA1c (mmol/mol) | Glycated Hemoglobin | Change from baseline HbA1c at 16 weeks | 
| Liver fat (%) | Intra-hepatic fat measured by Magnetic Resonance Imaging | Change from baseline liver fat at 16 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pancreatic fat (%) | Pancreatic fat measured by Magnetic Resonance Imaging | Change from pancreatic fat at 16 weeks | 
| Muscle fat (%) | Muscle fat measured by Magnetic Resonance Imaging | Change from baseline muscle fat at 16 weeks | 
| Concentrations of Fasting glucose | Plasma glucose measured after an overnight fast | Change from baseline fasting glucose at 16 weeks | 
| Concentrations of Fasting insulin | Plasma insulin measured after an overnight fast | Change from baseline fasting insulin at 16 weeks | 
| Concentrations of Fasting lipids | Plasma total cholesterol, HDL-Cholesterol, LDL-Cholesterol and Triglycerides measured after an overnight fast | Change from baseline fasting lipids at 16 weeks | 
| Concentrations of Liver enzymes | Alanine aminotransferase, Aspartate aminotransferase measured after an overnight fast | Change from baseline liver enzymes at 16 weeks | 
| Aerobic fitness | Submaximal exercise test to determine ventilatory threshold | Change from baseline aerobic fitness at 16 weeks | 
| Height (centimeters) | Standing height | Change from baseline height at 16 weeks | 
| Waist circumference (centimeters) | Waist circumference (between 12 rib and iliac crest) measures in centimeters | Change from baseline waist circumference at 16 weeks | 
| Hip circumference (centimeters) | Hip circumference (between 12 rib and iliac crest) measures in centimeters | Change from baseline hip circumference at 16 weeks | 
| Body weight (kilograms) | Weight will be measured in kilograms | Change from baseline weight at 16 weeks | 
| Continuous glucose monitoring | Continuous glucose monitoring outcomes (e.g., 24-hour mean glucose) | Change from the first two to the last two weeks of the 16 week interventions | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise, Glycated hemoglobin, Liver fat, Continuous glucose monitoring