Type 2 Diabetes and Exercise Function in Single Leg Exercises

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01793909
Recruitment Status : Completed
First Posted : February 18, 2013
Last Update Posted : June 8, 2018
Information provided by (Responsible Party):
University of Colorado, Denver

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.

Condition or disease Intervention/treatment Phase
Type 2 Diabetes Other: Single Leg Exercise Training Not Applicable

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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 43 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Role of Vascular Function: Oxygen Delivery vs Oxygen Utilization in the Exercise Impairment in Type 2 Diabetes
Study Start Date : June 2012
Actual Primary Completion Date : May 31, 2018
Actual Study Completion Date : May 31, 2018

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Single Leg Exercise
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).
Other: Single 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).
Other Name: Exercise Training

Primary Outcome Measures :
  1. Change in Oxygen delivery/Muscle utilization [ Time Frame: 4.5 hrs each, pre- and post- Exercise Intervention ]
    The investigators will evaluate the dynamics of leg blood flow (and thus oxygen delivery) using Doppler ultrasound, muscle deoxygenation (O2 extraction) using near infrared spectroscopy (NIRS), and pulmonary VO2 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 will be 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. This innovative set of experiments will be the beginning of an important link between metabolic abnormalities of T2DM and exercise capacity.

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Ages Eligible for Study:   30 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts 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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01793909

United States, Colorado
University of Colorado Denver, Anschutz Medical Campus
Aurora, Colorado, United States, 80045
Sponsors and Collaborators
University of Colorado, Denver
Principal Investigator: Judy Regensteiner, PhD University of Colorado, Denver

Responsible Party: University of Colorado, Denver Identifier: NCT01793909     History of Changes
Other Study ID Numbers: 06-0062
1564 ( Other Identifier: Clinical Translational Research Center - University Hospital )
1UL1TR001082 ( U.S. NIH Grant/Contract )
First Posted: February 18, 2013    Key Record Dates
Last Update Posted: June 8, 2018
Last Verified: June 2018

Keywords provided by University of Colorado, Denver:
Type 2 Diabetes
Exercise Impairment
Blood Flow
Muscle Oxygen Uptake
Exercise Training

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases