Type 2 Diabetes
Conditions
Keywords
Type 2 Diabetes, Exercise Impairment, Blood Flow, Muscle Oxygen Uptake, Exercise Training
Brief summary
This study plans to learn more about the effects of type 2 diabetes (T2DM) on exercise blood flow and muscle oxygen uptake. This study will evaluate & compare exercise function during single leg plantar flexion exercise in a total of 45 subjects from the Denver area (15 lean controls, 15 people with T2DM, and 15 overweight control subjects). Differences between the exercise responses in people with T2DM and healthy people will help further identify the disease process of T2DM and direct future research of treatments and interventions.
Detailed description
It is well established that functional exercise capacity and peak oxygen uptake (VO2) are reduced in patients with type 2 diabetes mellitus (T2DM) compared with healthy counterparts. The mechanisms underlying the exercise deficit in T2DM remain largely unknown, but previous work has suggested that reduced exercise blood flow and impaired submaximal VO2 may be contributing factors. Both of these findings are consistent with a peripheral impairment of skeletal muscle oxygen delivery, oxygen utilization, or both. Indeed, dysfunction of skeletal muscle metabolism plays a key role in the pathophysiology of T2DM, and considerable work has described abnormalities of oxidative function in the skeletal muscle of people with T2DM. Given this, it is likely that the causes of exercise intolerance in T2DM may relate to specific defects at the level of the skeletal muscle, particularly given that skeletal muscle blood flow and oxidative capacity are impaired in diabetes. However, to our knowledge, no one has related these peripheral muscle abnormalities to the diminished exercise function in this patient group. The overarching hypothesis for the proposed research is that both a failure to adequately increase muscle oxygen delivery following the onset of exercise and reduced oxidative function of skeletal muscle contribute to the acute oxygen deficit and diminished exercise tolerance that has been observed in patients with T2DM.
Interventions
OTHERSingle Leg Exercise Training
Following the completion of baseline testing, all 3 subject groups will undergo supervised single leg, exercise training of the index (dominant) calf muscle 5 days per week for two weeks - alternating weight-bearing single leg calf raises and single leg calf extensions by endurance resistance training (weight machine apparatus).
Sponsors
University of Colorado, Denver
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Men and women with and without type 2 diabetes * 30-70 years of age * Lean and overweight * Sedentary subjects not participating in a regular exercise program (\<one bout of exercise/week)
Exclusion criteria
* Documented cardiovascular disease * Uncontrolled hypertension: systolic blood pressure (SBP) \> 150, diastolic blood pressure (DBP)\> 110 * Obstructive pulmonary disease or asthma * Peripheral neuropathy * Subjects taking beta blockers, insulin, or Thiazolidinediones (TZD) * Current or past smoking within the last 2 years * Anemia * Control HbA1c \> 6, T2DM HbA1c \> 10 * Type 1 diabetes * Any implanted metal in subject's body
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Muscle Oxygen Saturation | 4.5 hrs each, pre- and post- Exercise Intervention | The investigators evaluated the dynamics of muscle deoxygenation (O2 extraction) using near infrared spectroscopy (NIRS) during single leg plantar flexion exercise to identify the predominant mechanisms of oxygen delivery versus oxygen utilization abnormalities in the muscle of T2DM during the transition from rest to exercise. These measurements were gathered continuously for 2-5 minutes of multiple exercise bouts within two visits, one prior to the exercise intervention period and one post exercise intervention. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Type 2 Diabetes Individuals with a diagnosis of type 2 diabetes | 20 |
| Overweight Controls Individuals with a BMI 25-30 but otherwise healthy. | 20 |
| Total | 40 |
Baseline characteristics
| Characteristic | Overweight Controls | Total | Type 2 Diabetes |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 6 Participants | 16 Participants | 10 Participants |
| Age, Categorical Between 18 and 65 years | 14 Participants | 24 Participants | 10 Participants |
| Age, Continuous | 54 years STANDARD_DEVIATION 12 | 57 years STANDARD_DEVIATION 11 | 60 years STANDARD_DEVIATION 9 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 3 Participants | 7 Participants | 4 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 2 Participants | 2 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 14 Participants | 30 Participants | 16 Participants |
| Region of Enrollment United States | 25 participants | 0 participants | 30 participants |
| Sex: Female, Male Female | 10 Participants | 20 Participants | 10 Participants |
| Sex: Female, Male Male | 10 Participants | 20 Participants | 10 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 3 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 |
Outcome results
Primary
Change in Muscle Oxygen Saturation
The investigators evaluated the dynamics of muscle deoxygenation (O2 extraction) using near infrared spectroscopy (NIRS) during single leg plantar flexion exercise to identify the predominant mechanisms of oxygen delivery versus oxygen utilization abnormalities in the muscle of T2DM during the transition from rest to exercise. These measurements were gathered continuously for 2-5 minutes of multiple exercise bouts within two visits, one prior to the exercise intervention period and one post exercise intervention.
Time frame: 4.5 hrs each, pre- and post- Exercise Intervention
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Type 2 Diabetes | Change in Muscle Oxygen Saturation | Pre-intervention | -10.7127 percentage | Standard Deviation 6.07805 |
| Type 2 Diabetes | Change in Muscle Oxygen Saturation | Post-intervention | -12.471 percentage | Standard Deviation 11.07039 |
| Overweight Controls | Change in Muscle Oxygen Saturation | Pre-intervention | -8.9149 percentage | Standard Deviation 6.68906 |
| Overweight Controls | Change in Muscle Oxygen Saturation | Post-intervention | -8.7883 percentage | Standard Deviation 7.49904 |