HART-D: Health Benefits of Aerobic and Resistance Training in Individuals With Type 2 Diabetes

Sponsor

Pennington Biomedical Research Center (Other)

Overall Status

Completed

CT.gov ID

NCT00458133

Collaborator

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (NIH)

262

Enrollment

Location

Arms

Duration (Months)

6.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The goal of the proposed study, Health Benefits of Aerobic and Resistance Training in individuals with type 2 diabetes (HART-D), is to compare the effect of resistance training alone (RT), resistance in combination with aerobic training (AT+RT), and aerobic training alone (AT) to standard care (SC) on hemoglobin A1C (HbA1C), in initially sedentary women and men with type 2 diabetes (T2D).

Condition or Disease	Intervention/Treatment	Phase
Type 2 Diabetes	Behavioral: exercise	N/A

Detailed Description

Although it is generally accepted that regular exercise provides substantial health benefits to individuals with T2D, the exact exercise prescription in terms of type (AT versus RT versus AT+RT) still remains an important research issue, particularly in regard to week-to-week glucose control as assessed by HbA1C.

There is a need for more adequately powered and well-controlled studies to examine the effects of RT, AT and AT+RT on HbA1C in individuals with T2D. With the incidence of T2D expected to increase dramatically in the coming years, it is essential to have a better understanding of the relative benefits of various exercise interventions. This information can help better formulate exercise recommendations for patients with T2D as well as potentially provide more exercise options, which is important given the small percentage of individuals with TD2 who regularly exercise. The study group was sedentary women and men with T2D, aged 30 to 75 years. We randomly assigned 262 individuals to an aerobic exercise training only group (AT; n=72), a resistance training only group (RT; n=73), a combination of aerobic plus resistance training (AT+RT; n=76), or a standard care group (SC; n=41). The AT individuals participated in 3 or 4 training sessions each week for 9 months progressing to a total energy expenditure of 12 kcal/kg/week (KKW), which is an exercise dose consistent with the current public health recommendations for physical activity for individuals with T2D. The target exercise intensity was 50%-80% of baseline VO2 max. The RT group participated in 3 sessions per week (9 exercises, 2-3 sets each), which focuses on large muscle groups. This RT regimen is based on the studies that most successfully improved HbA1C in individuals with T2D. Individuals in the AT+RT group completed 10 KKW of aerobic training and a reduced resistance-training regimen of 2 sessions per week (9 exercises, 1 set of each). The AT+RT regimen represents the exercise recommendations of the American College of Sports Medicine (ACSM) and the American Diabetes Association (ADA).

Simply stated, we compared the effect of resistance training alone, resistance in combination with aerobic training, and aerobic training alone to standard care on HbA1C, in initially sedentary women and men with T2D. The primary outcome measure was HbA1C, an integrated measure of blood glucose control over the past 8-12 weeks. Other outcomes of interest included resting blood pressure, C-reactive protein (CRP), total body fat, and lean muscle mass as measured by DEXA, cardiorespiratory fitness, muscular strength, and metabolic measures including serum cholesterol and triglycerides.

Study Design

Study Type:

Interventional

Actual Enrollment :

262 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Health Benefits of Aerobic and Resistance Training in Individuals With Type 2 Diabetes

Study Start Date :

Apr 1, 2007

Actual Primary Completion Date :

Mar 1, 2010

Actual Study Completion Date :

Jun 1, 2010

Arms and Interventions

Arm	Intervention/Treatment
Experimental: 1 We randomly assigned 72 individuals to an aerobic exercise training only group.	Behavioral: exercise compared effects on HbA1C on aerobic only, resistance only, combination of aerobic and resistance, and a stretching & relaxing groups.
Experimental: 2 We randomly assigned 73 individuals to an resistance exercise training only group.	Behavioral: exercise compared effects on HbA1C on aerobic only, resistance only, combination of aerobic and resistance, and a stretching & relaxing groups.
Experimental: 3 We randomly assigned 76 individuals to a combination of aerobic plus resistance training group.	Behavioral: exercise compared effects on HbA1C on aerobic only, resistance only, combination of aerobic and resistance, and a stretching & relaxing groups.
Placebo Comparator: 4 We randomly assigned 41 individuals to a stretching and relaxation group.	Behavioral: exercise compared effects on HbA1C on aerobic only, resistance only, combination of aerobic and resistance, and a stretching & relaxing groups.

Outcome Measures

Primary Outcome Measures

Hemoglobin A1C [at 9 months]

Secondary Outcome Measures

Fasting glucose [at 9 months]
Basal insulin [at 9 months]
Resting blood pressure [at 9 months]
C reactive protein [at 9 months]
Visceral adiposity [at 9 months]
Body Composition [at 9 months]
Cardiorespiratory fitness [at 9 months]
Muscular strength [at 9 months]
metabolic measures, including serum cholesterol and triglycerides [at 9 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

30 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Age 30-75 years
type 2 diabetes determined by self-report with verification
6.5% < HbA1C < 11%
sedentary lifestyle - not being physically active greater than or equal to 3 days per week for 20 minutes each time for the previous 6 months, and not performing regular resistance exercise

Exclusion Criteria:

inadequate control of co-morbid conditions
resting blood pressure greater than or equal to 160/100 mm Hg
Triglycerides greater than or equal to 500 mg/dL
BMI is greater than or equal to 48
current use of an insulin pump or insulin injections other than Lantus
metal object in the body that may interfere with MRI/MRS scans
factors that may limit adherence to intervention or affect conduct of the trial

unable or unwilling to communicate with staff, to provide written informed consent, or accept the randomized assignment
failure to complete behavioral run-in and baseline testing
hospitalization for depression in the last 6 months
not physically capable of performing the exercise required for the study protocols
consuming > 14 alcoholic beverages per week
plans to be away > 4 weeks in the next 9 months
lack of support from primary health care provider or family members
significant weight loss in the past year (>20 lbs) or current use of weight loss medications
current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder
another member of household is a participant or staff member of HART-D
bariatric surgery
other temporary intervening event, such as sick spouse, bereavement, or recent move
other medical, psychiatric, or behavioral limitations that, in the view of the principal investigator, may interfere with study participation or the ability to follow the intervention protocol

underlying diseases or conditions likely to limit lifespan and/or affect the safety of the intervention

pregnant or plan on becoming pregnant in the next 9 months
cancers requiring treatment in the past 5 years, unless prognosis is excellent
self-reported HIV or tuberculosis
history or evidence of serious arrythmias, cardiomyopathy, congestive heart failure, aortic aneurysm, or heart transplantation
renal disease: urine dipstick 4+ protein, serum creatinine is greater than or equal to 1.4 mg/dL (women) or is greater than or equal to 1.5 mg/dL (men) or currently receiving dialysis
any other medical condition or disease that is life threatening or that can interfere with or be aggravated by exercise
advanced neuropathy or retinopathy