Effect of Continuous vs Intermittent Aerobic Exercise on Glycemic Control in a Barbadian Population With Type 2 Diabetes

Study Overview
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Brief Summary
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The purpose of this study will be to evaluate and compare the effect of a single 30-minute bout of moderate intensity aerobic exercise to the effect of three 10-minute pre-prandial bouts of energy-matched and volume-matched aerobic exercise on 2-hr post prandial and fasting blood sugar levels, in a sample of type 2 diabetes patients, aged 30-65 years, living in Barbados Research Hypotheses: The three bouts of pre-prandial moderate intensity aerobic exercise will result in lower post prandial blood sugar levels when compared to the single bout of moderate intensity aerobic exercise. The three bouts of pre-prandial moderate intensity aerobic exercise will result in lower fasting blood sugar levels on the morning following the exercise intervention when compared to the single bout of moderate intensity aerobic exercise

Detailed Description
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With the background that there is increasing evidence that breaking up sedentary time with physical activity may be potentially associated with improved blood glucose levels (Francois et al., (2014) & van Dijk et al., (2013), this study aims to investigate and compare the effect of a single 30-minute bout of moderate intensity aerobic exercise to the effect of three 10-minute pre-prandial bouts of energy-matched and volume-matched aerobic exercise on 2-hr post prandial and fasting blood sugar levels in a sample of type 2 diabetes patients. Different from previous studies, this research seeks to evaluate these effects in a Black Caribbean population, in a type 2 diabetes population on medication including insulin and also seeks to evaluate if either exercise regimen is indeed palatable to the target population by evaluating treatment acceptability. The proposed study will be a crossover randomized controlled study. There will be two intervention groups - a single 30-minute bout of moderate intensity aerobic exercise before breakfast and three (3) 10-minute bouts of moderate intensity aerobic activity before breakfast, lunch and dinner. The primary outcome measure will be 2-hr post prandial blood sugar levels and fasting blood sugar levels on the day following the intervention. Neither subject nor investigator will be blinded to the intervention. Subjects will include patients with a documented diagnosis of type 2 diabetes, that is a documented HbA1C ≥ 6.5%. Baseline data will include body mass and body composition and will be measured using the bioelectrical impedance technique (Tanita scale). Waist circumference will be assessed using a Gulick tape measure. Baseline sedentary behaviour and physical activity level will be assessed using the validated International Physical Activity Questionnaire. All recruited subjects will be asked to complete two exercise interventions separated by a one-week washout period: 1) a single 30-minute bout of moderate intensity aerobic exercise before breakfast and 2) three (3) 10-minute bouts of moderate intensity aerobic activity before breakfast, lunch and dinner. Each subject will be randomized to one of two treatment sequences: single bout followed by multiple bouts (S-M) or multiple bouts followed by single bout (M-S). The randomization will be done using online statistical computing web programming (www.randomization.com) to generate a randomization schedule with balanced permutations. Timing between exercise completion and commencement of meal intake will be approximately 15 minutes. A heart rate reserve range of 40-59% will be used to define moderate intensity. Heart rate will be measured using a validated Polar heart rate monitor. Rate of perceived exertion will be a secondary measure of exercise intensity. Two-hour (2hr) post prandial blood sugar levels and fasting blood sugar levels on the day following the exercise intervention will be measured using a validated capillary blood glucose meter. Blood pressure will also be measured at the same times that blood glucose values are taken using a validated automated blood pressure machine. Standardized meals of fixed nutrient content and individualized to the subject's calculated estimated daily caloric requirements will be provided to subjects on the day of the exercise interventions. Treatment acceptability will be assessed following each exercise intervention using an expert-designed questionnaire that will be piloted in this study.

Official Title
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The Effect of Continuous Versus Intermittent Aerobic Exercise on Glycemic Control in a Barbadian Population With Type 2 Diabetes - A Crossover Randomized Control Trial

Conditions
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Diabetes Mellitus, Type 2

Intervention / Treatment
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* Behavioral: Single Bout ('S')
* Behavioral: Multiple Bout ('M')


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults aged 30-65 years Documented diagnosis of type 2 diabetes (HbA1C ≥ 6.5%) Exclusion Criteria: Subjects currently managed on prandial insulin Subjects who have recently started insulin (within the previous month) Subjects with a history of frequent hypoglycemic episodes within the previous 2 weeks, Pregnancy Subjects with a history of cerebrovascular accident, myocardial infarction, chronic kidney disease, autonomic and peripheral neuropathy Subjects with contraindications to exercise according to ACSM 2018 guidelines

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 65 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: Crossover Assignment
Interventional Model Description: The proposed study is a crossover randomized controlled study. There will be two intervention groups - a single 30-minute bout of moderate intensity aerobic exercise before breakfast and three (3) 10-minute bouts of moderate intensity aerobic activity before breakfast, lunch and dinner.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Single Bout ('S') - 30 minutes of moderate intensity cycling<br>Subjects will perform a single 30-minute bout of moderate intensity cycling before breakfast | Behavioral: Single Bout ('S')<br>* Each subject will perform a single bout of 30-minutes of moderate-intensity cycling before breakfast<br>|
| Experimental: Multiple Bout ('M')<br>Subjects will perform three (3) 10-minute bouts of moderate intensity cycling before breakfast, lunch and dinner | Behavioral: Multiple Bout ('M')<br>* Each subject will perform three (3) 10-minute bouts of moderate intensity cycling before breakfast, lunch and dinner<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 2 hour post prandial blood glucose level after breakfast | blood glucose level 2 hours after breakfast consumption | single point measurement taken 2 hours after breakfast consumption | 
| 2 hour post prandial blood glucose level after lunch | blood glucose level 2 hours after lunch consumption | single point measurement taken 2 hours after lunch consumption | 
| 2 hour post prandial blood glucose level after dinner | blood glucose level 2 hours after dinner consumption | single point measurement taken 2 hours after dinner consumption | 
| Fasting blood sugar level | blood sugar level after 8 hours of fasting performed on day following exercise intervention | single point measurement taken after 8 hours of fasting |