Mitochondrial Dysfunction in Type 2 Diabetes Mellitus and Capacity for Fat Oxidation During Exercise

April 24, 2014 updated by: University of Pittsburgh

The purpose of this study is to compare the effects of an 8-week aerobic training program upon fat oxidation in vivo and markers of skeletal muscle mitochondrial content and oxidative capacity in sedentary obese subjects with and without type 2 diabetes. We will also investigate if mitochondrial content in muscle predicts success of weight loss.

The specific aims are:

  • To compare systemic fat oxidation rates;
  • To measure mitochondrial content in muscle before and after aerobic training;
  • To determine if decreased mitochondrial content is also associated with decreased mitochondrial oxidative capacity;
  • To measure non-plasma fatty acid oxidation in vivo during submaximal exercise conditions both prior and after aerobic training;
  • To determine whether increases in fat oxidation due to physical activity predict weight loss success when a reduced calorie diet is added to a physical activity program.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Detailed Description

During prolonged moderate-intensity exercise, skeletal muscle gradually increases its metabolic reliance on fat oxidation. In healthy subjects, this adaptation is enhanced by aerobic training and is associated with increased mitochondrial capacity in muscle. Whether or not subjects with type-2 diabetes (T2DM) respond to exercise training with similar metabolic and mitochondrial adaptations is yet to be demonstrated. Skeletal muscle mitochondrial oxidative capacity has been shown to be deficient in T2DM, suggesting a compromised physiologic reserve that might have implications for the metabolic plasticity of muscle during exercise.

This study will test the hypothesis that fat oxidation rates during exercise are poorly responsive to training in T2DM, being correlated to the degree of muscle mitochondrial adaptation. The effects of a 16-week intervention (8 weeks of exercise intervention followed by 10-12 weeks of weight loss intervention) on systemic fat oxidation during exercise and mitochondrial capacity will be compared between 3 sedentary subject groups; 15 lean subjects, 15 overweight subjects with T2DM, and 15 overweight subjects without diabetes. The first aim is to compare the degree of improvement in fat oxidation during submaximal exercise obtained by indirect calorimetry. The second and third aims are, respectively, to compare the degree of improvement in mitochondrial content and oxidative capacity in muscle biopsy samples. The fourth aim is to determine whether fat oxidation from non-plasma sources is increased by the intervention. The final aim is to examine whether improvements in fat oxidation predict degree off success in a subsequent weight loss program.

The results of this study will be relevant to the understanding of the mechanisms by which exercise training confers metabolic improvements in T2DM. In addition, this study will address whether perturbations in mitochondria could explain why obese individuals with T2DM might have difficulty with fat disposal.

Study Type

Interventional

Enrollment (Actual)

29

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15213
        • University of Pittsburgh, Montefiore Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

28 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

Men and women, aged 28-55 year-old, in general good health and with no contraindications to exercise. We are recruiting three groups of subjects: Group 1: overweight/obese adults with type 2 diabetes, with a BMI between 28-40. Group 2: overweight/obese adults without type 2 diabetes, with a BMI between 28-40. Group 3: adults without type 2 diabetes, with a BMI equal or less than 25 (not overweight/obese.)

Exclusion Criteria:

Any condition that does not permit exercise; current participation in a regular physical activity; uncontrolled blood pressure; treatment with any of the following medications: insulin, any weight-loss drug, oral glucocorticoids, or any drugs that affect muscle and fat metabolism such as niacin, fibrates, and beta blockers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: exercise
Behavioral: Aerobic exercise program - 8 weeks
No drugs. Regular aerobic exercise in structured prescription format

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The degree of improvement in fat oxidation during submaximal exercise obtained by indirect calorimetry after subjects have completed an eight week aerobic exercise program.
Time Frame: 8 weeks
8 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
The degree of improvement in muscle mitochondrial content after eight week exercise program.
Time Frame: 8 weeks
8 weeks
The amount of improvement in muscle mitochondrial oxidative capacity after eight week exercise program.
Time Frame: 8 weeks
8 weeks
Increase in fat oxidation from non-plasma sources after the eight week intervention.
Time Frame: 8 weeks
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Pittsburgh

Collaborators

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

Investigators

  • Principal Investigator: Frederico G Toledo, MD, University of Pittsburgh

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2006

Primary Completion (Actual)

December 1, 2010

Study Completion (Actual)

December 1, 2010

Study Registration Dates

First Submitted

September 28, 2006

First Submitted That Met QC Criteria

September 28, 2006

First Posted (Estimate)

September 29, 2006

Study Record Updates

Last Update Posted (Estimate)

April 25, 2014

Last Update Submitted That Met QC Criteria

April 24, 2014

Last Verified

April 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 0605115

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Diabetes Mellitus, Type 2

Clinical Trials on Aerobic exercise program - 8 weeks

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Taiwan

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe