The Diabetes Aerobic and Resistance Bands Exercise (DARE-Bands) Trial

The Diabetes Aerobic and Resistance Bands Exercise (DARE-Bands) Trial

BACKGROUND Resistance exercise training with free weights or weight machines clearly improves glucose (sugar) control in type 2 diabetes (T2D). However, many patients with T2D would prefer not to attend an exercise facility, for reasons of cost and/or convenience. Coinvestigator Jonathon Fowles has developed and pilot-tested a home-based exercise program for people with T2D using resistance bands. However, the effects of resistance-bands training (on glucose control in T2D have not been evaluated in a high-quality randomized trial.

SPECIFIC AIMS To determine the effects of six months of progressive home-based resistance bands training (RBT) versus no RBT in people with T2D on blood glucose control (HbA1c, primary outcome), waist circumference, heart disease risk factors, and quality of life.

METHODS A total of 100 T2D participants will be randomized to 2 arms: home-based RBT (RBT-H) or aerobic training only (ATO). Both groups will accumulate 150 minutes per week of aerobic exercise such as walking. The resistance exercise workout includes 12 exercises, targeting all major muscle groups. RBT-H subjects will complete most exercise at home with periodic supervision.

SIGNIFICANCE The global burden of type 2 diabetes is increasing, and complications of the illness occur primarily in those whose glucose control is fair or poor. If exercise training with resistance bands improves glucose control, it could be beneficial to the large numbers of patients who cannot travel to a gym or cannot afford gym membership. If resistance exercise is then adopted by more patients, it is likely that the morbidity associated with type 2 diabetes will be decreased. This is particularly true if such training also improves quality of life, and more people are thus inclined to continue exercising in the long term.

BACKGROUND Resistance exercise training with free weights or weight machines clearly improves glycemic control in type 2 diabetes (T2D). However, many patients with T2D would prefer not to, or are not able to attend an exercise facility,for reasons of cost, comfort or convenience. Coinvestigator Dr. Jonathon Fowles developed a home-based exercise program for people with T2D using resistance bands. Before-after studies using this intervention have found improvements in glycemic control, strength, and blood pressure. However, the effects of resistance-bands training (RBT) on glycemic control in T2D have not been evaluated in a high-quality randomized trial.

RESEARCH QUESTIONS To determine the effects of six months of progressive home-based RBT plus aerobic exercise, versus home-based aerobic exercise alone, in previously-sedentary people with T2D.

METHODS After a 2-week run-in period to assess adherence, 100 T2D subjects not currently engaging in regular exercise will be randomized in equal numbers to 2 arms: primarily home-based RBT (RBT-H) or aerobic only control (ATO) . Both groups will complete aerobic training: accumulation of 150 minutes per week of walking or jogging, measured by accelerometers. The RBT workout will include 12 distinctive exercises, targeting all major muscle groups. Subjects will be trained in groups led by a Kinesiologist (exercise specialist) twice per week for two weeks during run-in. After randomization, the RBT-H group will perform RBT three times per week. RBT-H participants will perform RBT three times per week primarily at home, with supervised group sessions weekly in weeks 1-4, every 2 weeks in weeks 5-8, and every 4 weeks thereafter to ensure proper form and appropriate progression. Adherence to RBT will be verified through direct supervision of group sessions, and completion of detailed exercise logs for home-based and group sessions. Participants will photograph the log after each session and email the photo to a designated email address. Study outcomes will be assessed at baseline, 12 and 24 weeks post-randomization. Dietary advice will be standardized through repeated sessions with a dietician, and doses of medications altering glucose, lipids and BP will be held constant unless change is medically urgent. Primary analyses will be intention-to-treat, using repeated measures mixed modeling. Per-protocol analyses will be done including only subjects who completed >70% of prescribed exercise sessions and all end-of-study outcome measures.

SIGNIFICANCE The global burden of type 2 diabetes is increasing, and complications of the illness occur primarily in those whose glycemic control is fair or poor. If home-based exercise training with resistance bands improves glycemic control and other vascular risk factors, it could be beneficial to the large numbers of patients who prefer not to have to travel to a gym or cannot afford gym membership. If resistance exercise is then adopted by more patients, it is likely that the morbidity associated with type 2 diabetes will be decreased. This is particularly true if such training also improves quality of life, and more people are thus inclined to continue exercising in the long term.

Inclusion Criteria:

1. Adults aged >35 years with T2D as defined by the CDA Expert Committee.
2. A1C values within range of 6.6%-9.9%.
3. Willingness to follow study procedures (e.g. wear the accelerometer for exercise sessions and download them at least weekly, complete exercise logs, attend supervised group-based resistance band sessions, perform resistance bands exercise at home).

Exclusion Criteria:

1. Participation in a regular program of physical conditioning or aerobic sports/activities for >150 minutes per week during the 6 months prior to enrolment.
2. Participation in any resistance exercise training during the previous 6 months.
3. Requirement for insulin therapy currently or in the previous 3 months.
4. Uncontrolled hyperglycemia (A1C > 10%), as it would be a clear indication for cointervention.
5. Uncontrolled hypertension: systolic BP >160 mmHg or diastolic BP >100 mmHg, both measured in sitting position. If too-high A1C or BP is the only reason for exclusion, subjects will be asked to see their physicians regarding the hyperglycemia or BP, and invited to re-apply for the study several months later if the problem is under better control.
6. Hypo-glycemia unawareness, or severe hypoglycemia requiring assistance from another person within the previous 3 months.
7. Restrictions in physical activity due to disease: unstable cardiac or pulmonary disease, severe aortic stenosis, Marfan's syndrome (risk of aortic dissection from resistance training), intermittent claudication sufficient to interfere with aerobic exercise progression, severe peripheral neuropathy or active proliferative retinopathy, disabling stroke, severe arthritis, musculoskeletal injuries compromising safety of the prescribed exercises, inability to walk 10 minutes.
8. Other illness, judged by the patient or study physician to make participation in this study inadvisable.
9. Inability to understand or comply with instructions.
10. Pregnancy at the start of the study, or intention to become pregnant in the next 6 months.
11. Plans to move to a different city within the next 12 months.
12. Inability to communicate in English or French.
13. Unwillingness to sign informed consent.