Insulin Resistance, Type 2 Diabetes
Conditions
Keywords
Exercise Training, Strength Training, African American Men, Insulin Resistance
Brief summary
The purpose of this study is to investigate the effect of an exercise training intervention on the ability of African American males to use insulin properly. Insulin is a hormone that helps the body use glucose.
Detailed description
This study is designed to assess the effect of exercise training on insulin resistance in African American males. African American males have higher rates of diabetes and lower levels of fitness when compared to Caucasian males. A project such as this is necessary because there is evidence to show that exercise training can reduce the risk of developing diabetes, though no studies have been conducted in African American males. In addition, ARTIIS will test the effect adhering to the 2008 Physical Activity Guidelines for Americans (150 minutes of moderate intensity aerobic activity and 2 days of 20 minutes of muscular strength activity), on insulin resistance in African American men. This study will provide important information that can either strengthen or refine current physical activity recommendations. Furthermore, this intervention will be delivered through community facilities in order to increase the likelihood that the intervention will be sustainable.
Interventions
BEHAVIORALAerobic Plus Resistance Training Group
Participants randomized to this intervention will engage in both aerobic and resistance training in accordance with Physical Activity Guidelines for Americans, that is 150 minutes of aerobic training and 2 days of additional 20 minutes of resistance training. The aerobic training component will be completed on a treadmill and target training intensity will be self-selected at 65% to 85% of maximal aerobic capacity. Each resistance training session will consist of both upper and lower body exercises: 2 sets of 9 exercises with each set consisting of 10 repetitions.
BEHAVIORALControl Group
Participants randomized into the control group will not be provided with memberships to any exercise facility, nor will they receive behavioral instruction on how to increase physical activity. They will receive information on living a healthy lifestyle. Such minimal interventions have not been shown to increase physical activity in participants. The participants in this group will undergo the baseline, 10 week, and 20 week testing.
Sponsors
Pennington Biomedical Research Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
35 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* You completed the three run-in screening visits. * You self-identify as a male of African descent. * You are 35 to 70 years of age. * You have a BMI (ratio of your height to your weight) greater than or equal to 25.0 kg/m2 and less than or equal to 40 kg/m2. * You have a family history of diabetes. * You are not currently physically active for 20 minutes each time for 3 or more days per week for the last 6 months. You are not participating in regular muscle building exercise. * You are willing to give informed consent, willing to be randomized to either the healthy living intervention group or the aerobic plus resistance training exercise group, and willing to follow the protocol for the group to which you have been assigned.
Exclusion criteria
* You drink more than 14 alcoholic drinks per week. * You plan to move out of the study area within the next 6 months, or plan to be out of the study area for more than 4 weeks during the course of the study. * You have another member of your household participating in the study. * You have serious health conditions that would interfere with the intervention goals * History of cardiovascular disease (CVD) or disorders and are not under the care of a physician to treat the condition, or fail to provide written documentation from your physician indicating that the physician approves of your entering the study * Have high blood pressure (greater than 155/99 mmHg) and are not under the care of a physician to treat the condition or fail to provide written documentation from your physician indicating that the physician approves of your entering the study * Have a previous diagnosis of diabetes (Type 1 or 2) or a fasting plasma glucose of \>125 mg/dl * Have elevated bad cholesterol (greater than or equal to 190mg/dl) or triglycerides (great than or equal to 300) and are not under the care of a physician to treat the condition or fail to provide written documentation from your physician indicating that the physician approves of you entering the study * Are currently taking medications for diabetes or chronic steroid use * Have chronic or recurrent respiratory, gastrointestinal, neuromuscular, neurological or psychiatric conditions * Have had cancer requiring treatment in the past 5 years, expect for non-melanoma skin cancers or cancers that have clearly been cured or in the option of the investigator carry an excellent prognosis (e.g., Stage 1 cervical cancer) * Have autoimmune or collagen vascular diseases * Have immunodeficiency diseases or HIV * You have any other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator are life-threatening or that may interfere with study participation or the ability to follow the intervention protocol.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Baseline, week 10, week 20 | An oral glucose tolerance test is a medical test in which glucose is given and blood samples are taken afterward to determine how quickly it is cleared from the blood. The test is usually used to test for diabetes or insulin resistance. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Systolic Blood Pressure | 20 weeks | Blood pressure was measured at rest using a standard mercury sphygmomanometer. |
| Body Composition | 20 weeks | Body composition was assessed using the General Electric (General Electric; Milwaukee, WI) Lunar i-Dual energy X-ray absorptiometry. |
| Cardiorespiratory Fitness | 20 weeks | Fitness testing is being used as a measure of change in the aerobic component of the intervention. Cardiorespiratory fitness maximal exercise tests were conducted using a standardized graded exercise testing protocol administered on a treadmill. |
| Diastolic Blood Pressure | 20 weeks | Blood pressure was measured at rest using a standard mercury sphygmomanometer. |
| Mood | 20 weeks | Depressive symptomatology is measured by the Center for Epidemiology Studies Depression Scale (CES-D). The total score range is 0 to 60. Higher scores represent higher levels of depressive symptomatology. |
| Mental Health | 20 weeks | The Health Related Quality of Life (SF-36) questionnaire is being used to assess perceived quality of life, which usually improves through regular exercise. The measure is scored on a T-scale, with a mean of 50 and standard deviation of 10. Higher scores represent better functioning. Scores below 40 suggest poorer functioning than normal, and scores above 60 represent better functioning than normal. |
| Physical Health | 20 weeks | The Health Related Quality of Life (SF-36) questionnaire is being used to assess perceived quality of life, which usually improves through regular exercise. The measure is scored on a T-scale, with a mean of 50 and standard deviation of 10. Higher scores represent better functioning. Scores below 40 suggest poorer functioning than normal, and scores above 60 represent better functioning than normal. |
| Muscular Strength | 20 weeks | Strength testing is performed in order to assess change in response to the resistance training program. Muscular strength is measured via isokinetic testing on a Biodex System 4 Isokinetic Dynamometer. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Control Group We will randomly assign 52 individuals to a no exercise healthy living group.
Control Group: Participants randomized into the control group will not be provided with memberships to any exercise facility, nor will they receive behavioral instruction on how to increase physical activity. They will receive information on living a healthy lifestyle. Such minimal interventions have not been shown to increase physical activity in participants. The participants in this group will undergo the baseline, 10 week, and 20 week testing. | 56 |
| Aerobic Plus Resistance Training Group We will randomly assign 52 individuals to an aerobic plus resistance training group.
Aerobic Plus Resistance Training Group: Participants randomized to this intervention will engage in both aerobic and resistance training in accordance with Physical Activity Guidelines for Americans, that is 150 minutes of aerobic training and 2 days of additional 20 minutes of resistance training. The aerobic training component will be completed on a treadmill and target training intensity will be self-selected at 65% to 85% of maximal aerobic capacity. Each resistance training session will consist of both upper and lower body exercises: 2 sets of 9 exercises with each set consisting of 10 repetitions. | 57 |
| Total | 113 |
Baseline characteristics
| Characteristic | Aerobic Plus Resistance Training Group | Control Group | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 2 Participants | 5 Participants | 7 Participants |
| Age, Categorical Between 18 and 65 years | 55 Participants | 51 Participants | 106 Participants |
| Age, Continuous | 50.54 Years STANDARD_DEVIATION 9.59 | 53.6 Years STANDARD_DEVIATION 8.13 | 51.99 Years STANDARD_DEVIATION 8.97 |
| Region of Enrollment United States | 57 participants | 56 participants | 113 participants |
| Sex: Female, Male Female | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 57 Participants | 56 Participants | 113 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 4 / 56 | 16 / 57 |
| serious Total, serious adverse events | 0 / 56 | 1 / 57 |
Outcome results
Primary
Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks.
An oral glucose tolerance test is a medical test in which glucose is given and blood samples are taken afterward to determine how quickly it is cleared from the blood. The test is usually used to test for diabetes or insulin resistance.
Time frame: Baseline, week 10, week 20
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Baseline | 110.51 uU/mL | Standard Error 8.14 |
| Control Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Week 10 | 90.68 uU/mL | Standard Error 8.13 |
| Control Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Week 20 | 86.7 uU/mL | Standard Error 7.3 |
| Aerobic Plus Resistance Training Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Baseline | 106.64 uU/mL | Standard Error 7.77 |
| Aerobic Plus Resistance Training Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Week 10 | 80.23 uU/mL | Standard Error 6.52 |
| Aerobic Plus Resistance Training Group | Insulin Response to an Oral Glucose Tolerance Test Over 20 Weeks. | Week 20 | 80.74 uU/mL | Standard Error 7.25 |
Secondary
Body Composition
Body composition was assessed using the General Electric (General Electric; Milwaukee, WI) Lunar i-Dual energy X-ray absorptiometry.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Body Composition | Baseline | 100.79 kg | Standard Error 2.54 |
| Control Group | Body Composition | Week 20 | 99.46 kg | Standard Error 2.82 |
| Aerobic Plus Resistance Training Group | Body Composition | Baseline | 99.75 kg | Standard Error 2.25 |
| Aerobic Plus Resistance Training Group | Body Composition | Week 20 | 97.97 kg | Standard Error 2.39 |
Secondary
Cardiorespiratory Fitness
Fitness testing is being used as a measure of change in the aerobic component of the intervention. Cardiorespiratory fitness maximal exercise tests were conducted using a standardized graded exercise testing protocol administered on a treadmill.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Cardiorespiratory Fitness | Baseline | 2.41 L/min of oxygen | Standard Error 0.07 |
| Control Group | Cardiorespiratory Fitness | Week 20 | 2.3 L/min of oxygen | Standard Error 0.09 |
| Aerobic Plus Resistance Training Group | Cardiorespiratory Fitness | Baseline | 2.41 L/min of oxygen | Standard Error 0.07 |
| Aerobic Plus Resistance Training Group | Cardiorespiratory Fitness | Week 20 | 2.6 L/min of oxygen | Standard Error 0.09 |
Secondary
Diastolic Blood Pressure
Blood pressure was measured at rest using a standard mercury sphygmomanometer.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Diastolic Blood Pressure | Week 20 | 79.16 mmHg | Standard Error 1.09 |
| Control Group | Diastolic Blood Pressure | Baseline | 81.2 mmHg | Standard Error 1.04 |
| Control Group | Diastolic Blood Pressure | Week 10 | 72.13 mmHg | Standard Error 1.04 |
| Aerobic Plus Resistance Training Group | Diastolic Blood Pressure | Baseline | 81.74 mmHg | Standard Error 1.16 |
| Aerobic Plus Resistance Training Group | Diastolic Blood Pressure | Week 10 | 70.8 mmHg | Standard Error 1.06 |
| Aerobic Plus Resistance Training Group | Diastolic Blood Pressure | Week 20 | 79.85 mmHg | Standard Error 1.27 |
Secondary
Mental Health
The Health Related Quality of Life (SF-36) questionnaire is being used to assess perceived quality of life, which usually improves through regular exercise. The measure is scored on a T-scale, with a mean of 50 and standard deviation of 10. Higher scores represent better functioning. Scores below 40 suggest poorer functioning than normal, and scores above 60 represent better functioning than normal.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Mental Health | Week 20 | 57.27 T-score | Standard Error 0.71 |
| Control Group | Mental Health | Baseline | 56.59 T-score | Standard Error 0.85 |
| Aerobic Plus Resistance Training Group | Mental Health | Week 20 | 54.41 T-score | Standard Error 1.21 |
| Aerobic Plus Resistance Training Group | Mental Health | Baseline | 55.53 T-score | Standard Error 0.89 |
Secondary
Mood
Depressive symptomatology is measured by the Center for Epidemiology Studies Depression Scale (CES-D). The total score range is 0 to 60. Higher scores represent higher levels of depressive symptomatology.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Mood | Week 20 | 10.09 score on a scale | Standard Error 0.99 |
| Control Group | Mood | Baseline | 5.75 score on a scale | Standard Error 0.59 |
| Aerobic Plus Resistance Training Group | Mood | Baseline | 6.05 score on a scale | Standard Error 0.66 |
| Aerobic Plus Resistance Training Group | Mood | Week 20 | 10.37 score on a scale | Standard Error 1.04 |
Secondary
Muscular Strength
Strength testing is performed in order to assess change in response to the resistance training program. Muscular strength is measured via isokinetic testing on a Biodex System 4 Isokinetic Dynamometer.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Muscular Strength | Week 20 | 3999.5 Joules | Standard Error 984.3 |
| Control Group | Muscular Strength | Baseline | 3926.1 Joules | Standard Error 788.2 |
| Aerobic Plus Resistance Training Group | Muscular Strength | Baseline | 4011.0 Joules | Standard Error 833.2 |
| Aerobic Plus Resistance Training Group | Muscular Strength | Week 20 | 4113.7 Joules | Standard Error 972.3 |
Secondary
Physical Health
The Health Related Quality of Life (SF-36) questionnaire is being used to assess perceived quality of life, which usually improves through regular exercise. The measure is scored on a T-scale, with a mean of 50 and standard deviation of 10. Higher scores represent better functioning. Scores below 40 suggest poorer functioning than normal, and scores above 60 represent better functioning than normal.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Physical Health | Baseline | 55.84 T-score | Standard Error 0.51 |
| Control Group | Physical Health | Week 20 | 54.96 T-score | Standard Error 0.79 |
| Aerobic Plus Resistance Training Group | Physical Health | Baseline | 55.35 T-score | Standard Error 0.8 |
| Aerobic Plus Resistance Training Group | Physical Health | Week 20 | 53.4 T-score | Standard Error 1.11 |
Secondary
Systolic Blood Pressure
Blood pressure was measured at rest using a standard mercury sphygmomanometer.
Time frame: 20 weeks
Population: The number analyzed differs by row because some participants did not complete the follow-up measures.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Control Group | Systolic Blood Pressure | Baseline | 123.04 mm Hg | Standard Error 1.5 |
| Control Group | Systolic Blood Pressure | Week 10 | 116.13 mm Hg | Standard Error 1.53 |
| Control Group | Systolic Blood Pressure | Week 20 | 120.06 mm Hg | Standard Error 1.6 |
| Aerobic Plus Resistance Training Group | Systolic Blood Pressure | Baseline | 124.39 mm Hg | Standard Error 1.62 |
| Aerobic Plus Resistance Training Group | Systolic Blood Pressure | Week 10 | 114.84 mm Hg | Standard Error 1.64 |
| Aerobic Plus Resistance Training Group | Systolic Blood Pressure | Week 20 | 122.68 mm Hg | Standard Error 1.76 |