Diabetes Mellitus, Type 2, Exercise, Physical Activity, PreDiabetes
Conditions
Keywords
Exercise Response, Interindividual Variability
Brief summary
Large interindividual variability exists in the glycemic response to exercise program, resulting in a subset of individuals known as exercise non-responders (NRs). Increasing the intensity of an exercise intervention has been proposed as one method for rescuing NRs by producing beneficial changes. However, this theory has not been tested on NRs classified using glycemic outcomes. This study will evaluate if increasing the intensity of an exercise intervention will elicit a response within previous exercise NRs.
Detailed description
Exercise can effectively slow the progression towards Type 2 diabetes (T2D). However, data suggest large interindividual variability exists in glycemic response to exercise, resulting in a subset of individuals known as exercise non-responders (NRs). Emerging research proposes that altering the parameters of an exercise intervention to provide a sufficient stimulus can elicit a response in those previously identified as NRs. To date, no research has attempted to rescue previously classified NRs based on glycemic outcomes by altering the parameters of an exercise intervention. This study will implement an exercise program targeted at achieving the Canadian Physical Activity Guidelines, and calculate the number of NRs. We will then evaluate if increasing the intensity of exercise will elicit response to the treatment in the NRs. Sixty adults living with prediabetes or T2D will be recruited into one of a control group, or an exercise group. The exercising participants will begin a 16-week exercise intervention, targeted at achieving 150 minutes of moderate to vigorous intensity (equating to 4.5 METs) aerobic physical activity per week. Following the 16-week exercise program, participants will be randomized into two groups, each completing an additional 12 weeks of exercise. The first will maintain the same time and intensity, while the other will complete the 150 minutes per week at an intensity equal to 6.0 METs. Randomization will occur in blocks in order to ensure an equal number of NRs in each group.
Interventions
BEHAVIORALMaintained Exercise
Complete 28 weeks of aerobic exercise, with one week (following week 16) for testing. Week 1 - 16 Intensity: 4.5 metabolic equivalents (METs). Duration: Week 1: 80 minutes Week 2: 100 minutes Week 3: 120 minutes Week 4: 135 minutes Week 5 - 16: 150 minutes/week Week 17: Physiological Testing Week 18 - 29 Intensity: 4.5 METs Duration: 150 minutes/week All exercise must be completed across a minimum of two sessions per week. Sub-maximal exercise tests will be completed every 4 weeks to adjust intensity.
BEHAVIORALIncreased Intensity
Complete 28 weeks of aerobic exercise, with one week (following week 16) for testing. Week 1 - 16 Intensity: 4.5 metabolic equivalents (METs). Duration: Week 1: 80 minutes Week 2: 100 minutes Week 3: 120 minutes Week 4: 135 minutes Week 5 - 16: 150 minutes/week Week 17: Physiological Testing Week 18 - 29 Intensity: 6.0 METs Duration: 150 minutes/week All exercise must be completed across a minimum of two sessions per week. Sub-maximal exercise tests will be completed every 4 weeks to adjust intensity.
Sponsors
Heart and Stroke Foundation of Canada
New Brunswick Health Research Foundation
University of New Brunswick
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Participants will first be randomized as controls or exercisers. All exercisers will complete a 16 week exercise program, then be randomized into two groups. The first group will increase the exercise intensity and conduct another 12 week program. The second group will continue the original program for an additional 12 weeks.
Eligibility
Sex/Gender
ALL
Age
19 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
1. Community-dwelling adults aged 19 years or older. 2. Currently living with prediabetes or T2DM as diagnosed by a physician and confirmed by an HbA1c value of 5.7% or above, as verified by duplicate testing. 3. Not currently partaking in a self-reported regular physical activity regimen, defined as consistent participation in running or jogging activity, attending physical activity or exercise classes on a weekly basis, or averaging 10,000 steps per day or more over the course of 7 days.
Exclusion criteria
1. Self reported as currently diagnosed as having, or being treated for, low iron concentrations or anemia. 2. Diagnosed with any red blood cell altering condition. 3. Currently living with any cardiovascular disease which would impact the ability to safely participate in exercise training. 4. Currently prescribed any medication which would impact the ability to use a heart rate monitor to accurately track exercise intensity.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Exercise responders following initial program | Week 17 | The number of responders to the original 16-week exercise program, based on improvement in glycated hemoglobin |
| Exercise responders following additional exercise program | Week 30 | The number of responders following the additional 12-week exercise program, based on improvement in glycated hemoglobin |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Height | Baseline, week 17 and week 30 | Height (centimetres) |
| Waist circumference | Baseline, week 17 and week 30 | Waist circumference (cm) |
| Fat mass | Baseline, week 17 and week 30 | Fat mass (kg) |
| Fat free mass | Baseline, week 17 and week 30 | Fat free mass (kg) |
| Cardiorespiratory fitness | Baseline, week 17 and week 30 | VO2 peak |
| Daily step count | Baseline | Daily step count as recorded over a 7-day period |
| Current medication use | Baseline | Record of quantity and dose of current medications |
| Physical activity patterns | Baseline | Participant self-reported physical activity patterns and daily step counts over a 7-day period. |
| Sex | Baseline | Participant self-reported biological sex |
| Family history of cardiovascular disease | Baseline | Self-reported family history of cardiovascular disease |
| Body mass index | Baseline, week 17, week 30 | Weight (kilograms) and height (measured in centimetres and converted to metres) will be combined to report body mass index in kg/m\^2 |
| Family history of cardiometabolic disease | Baseline | Self-reported family history of cardiometabolic disease |
| Body mass | Baseline, week 17 and week 30 | Body mass (kilograms) |
Countries
Canada
Outcome results
None listed