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CompletedNCT03419195Updated Jul 12, 2023

Cardiovascular Mechanisms of Exercise Intolerance in Diabetes and the Role of Sex

An interventional study of Cardiovascular exercise training in Type 2 Diabetes Mellitus, Healthy and Overweight, sponsored by University of Colorado, Denver. Completed at 1 site in United States. Open to participants aged 30 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-07-12.

Sponsored by University of Colorado, Denver · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
124
Allocation
Non-randomized
Ages
30 Years to 55 Years
Sex
All
01

Study summary

This study will define the relationship of cardiac, vascular function and skeletal muscle blood flow (individually and together) to cardiovascular exercise capacity in in men and women with and without type 2 diabetes (T2DM). Identification of differences in the effects of exercise training on the integrated cardiovascular system and metabolism in men and women with and without T2DM will reveal specific adaptive responses to exercise.This study will evaluate \& compare exercise function in a total of 60 subjects from the Denver area (30 people with T2DM and 30 overweight control subjects).

Specific Aim 1: To test the hypothesis that the integration of cardiac function, macrovascular function, and microvascular function is impaired in T2D and correlates with cardiovascular exercise capacity (CVEC) impairment.

Specific Aim 2: To test the hypothesis that exercise training will elicit adaptive responses in cardiac and vascular function, muscle perfusion and metabolism with differences by T2D status.

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.

Read the 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 the knowledge of the investigators, 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 impaired CVEC in T2DM is the result of preclinical cardiac, vascular dysfunction and skeletal muscle perfusion abnormalities. Exercise training will improve CVEC and will reveal specific reversible therapeutic aspects of this pathology. The investigators will first determine the impairments and then evaluate responses to an established cardiac rehabilitation exercise training program, established to improve fitness in people with and without diabetes. Given the greater CVEC abnormalities observed in women, sex differences will be evaluated for each aim.

02

Conditions studied

  • Type 2 Diabetes Mellitus
  • Healthy
  • Overweight
  • Cardiovascular Risk Factor

Keywords

  • Type 2 Diabetes
  • Overweight
  • Exercise Training
  • Exercise Impairment
  • Healthy Control
  • Veteran
  • Blood Flow
03

Who can participate

Ages eligible
30 Years to 55 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Men and women with and without type 2 diabetes
  • BMI 25-40
  • Sedentary subjects not participating in a regular exercise program (\<one bout of exercise/week)

Exclusion criteria

Exclusion Criteria:

  • Documented cardiovascular disease
  • Uncontrolled hypertension: disease systolic blood pressure (SBP) > 150, diastolic blood pressure (DBP)> 110
  • Obstructive pulmonary disease or asthma
  • Peripheral neuropathy
  • Physical impairment that would limit exercise ability
  • Subjects taking beta blockers, calcium channel blockers, insulin, or Thiazolidinediones (TZD)
  • Current or past smoking within the last 1 years
  • Current tobacco use
  • Anemia
  • Control HbA1c > 5.7, T2DM HbA1c > 9
  • Pregnant, nursing or hormonal therapy (other than contraceptives)
  • Peri or post-menopausal women
  • Type 1 diabetes
  • Hepatic or renal disease.
  • Peptic ulcer disease.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
124 participants (actual)

Study arms

  • Experimental
    Type 2 diabetes

    Men and women between the ages of 30-55 with well controlled type 2 diabetes (A1C \<9%).

    Other: Cardiovascular exercise training

  • Experimental
    Healthy overweight controls

    Men and women between the ages of 30-55 with BMI 25-40 and limited immediate family history of type 2 diabetes.

    Other: Cardiovascular exercise training

Interventions

  • OtherCardiovascular exercise training

    Following the completion of baseline testing, both subject groups will undergo supervised cardiovascular exercise training 3 times per week for 3 months (plus a 3 week ramp-up). Exercise training will take place on a treadmill, stationary bicycle, elliptical, rowing machine, or combination of machines. Each session will last 1 hour, which includes a 5 minute warm-up, 50 minutes of exercise, and a 5 minute cool down.

    Also known as: Exercise Training

05

What researchers measure

Primary outcomes

  1. Change in peak oxygen consumption (VO2peak)

    Subjects' peak oxygen consumption will be tested on a stationary bike before and after 3 months of exercise

    Time frame: Through study completion, approximately 4 months

  2. Change in insulin sensitivity

    The investigators will evaluate the changes in insulin sensitivity utilizing a euglycemic insulin clamp

    Time frame: Through study completion, approximately 4 months

  3. Change in muscular mitochondrial function

    The investigators will examine mitochondrial function using magnetic resistance (MR) spectroscopy during single leg calf exercise

    Time frame: Through study completion, approximately 4 months

06

Study locations

1 site
  • University of Colorado, Anschutz Medical Campus
    Aurora, Colorado 80045, United States
07

References and documents

Study documents

  • Informed consent form · Apr 24, 2019

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

08

Registry details

Key details

Study ID
NCT03419195
Lead sponsor
University of Colorado, Denver
Collaborators
VA Eastern Colorado Health Care System
Responsible party
Sponsor
First posted
Feb 1, 2018
Start date
Feb 7, 2018
Primary completion
Mar 20, 2023
Completion
Mar 20, 2023
Last update
Jul 12, 2023

Study contacts

Judy Regensteiner, PhD
principal investigator · University of Colorado, Denver

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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