Improving Individual Glycemic Response With Exercise Intensity (INTENSITY)

University of New Brunswick

Status: Completed

Conditions: Physical Activity; Diabetes Mellitus, Type 2; Exercise; PreDiabetes

Treatments: Behavioral: Maintained Exercise; Behavioral: Increased Intensity

Study type: Interventional

Funder types: Other

Identifiers

NCT03787836

2018-168

Details and patient eligibility

About

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.

Full 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.

Enrollment: 61 patients

Sex: All

Ages: 19 to 85 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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61 participants in 3 patient groups

Controls

No Intervention group

Description:

The primary purpose of the control participants are to provide a measure of variability. They will be used in our calculations of typical error to classify participants as responders or non-responders, and to quantify inter-individual variability.

Exercisers (Maintained)

Experimental group

Description:

The maintained exercise group will complete the original 16-week exercise intervention at an intensity of 4.5 metabolic equivalents (METs), and repeat the intervention for another 12-weeks following its completion.

Treatment:

Behavioral: Maintained Exercise

Exercisers (Increased Intensity)

Experimental group

Description:

The increased intensity exercise group will complete the original 16-week exercise intervention, followed by an additional 12 week intervention completed at an intensity of 6.0 METs.

Treatment:

Behavioral: Increased Intensity