Effects of Acute Exercise on Acetylcarnitine Concentration in Endurance Trained and Untrained Subjects

It has been suggested that imbalance between TCA-cycle flux and β-oxidation may underlie insulin resistance, a predisposing factor for the development of type 2 diabetes mellitus. Acetylcarnitine concentration is suggested to be a marker of such imbalance. It is expected that when TCA-cycle capacity is high (a high oxidative capacity), less acetylcarnitine will accumulate, because of an improved balance between supply and demand of lipids.

The major research objective is to examine if acute exercise results in a more pronounced increase in acetylcarnitine concentration in sedentary subjects compared to endurance-trained subjects and if the exercise-induced increase in acetylcarnitine is restored more quickly in endurance-trained subjects when compared to sedentary subjects.

The investigators hypothesize that the increase in acetylcarnitine levels will be lower in trained subjects when compared to sedentary subjects, due to a better balance between lipid supply and utilization by the TCA-cycle. Furthermore it is expected that acetylcarnitine concentrations will be restored faster in these trained subjects, because of a tighter regulation of influx of fatty acids.

To test this hypothesis the investigators want to compare the acetylcarnitine response to exercise in a group of sedentary subjects and a group of endurance trained subjects. This response will be measured for 30 minutes after exercise with the use of 1H-MRS.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 2
• Intervention / Treatment: Other: Cycling

• Study Type: Interventional
• Enrollment (Actual): 9
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands, 6202 AZ
      • Maastricht University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Normal weight (BMI 18-25 kg/m2)
• Healthy
• Stable dietary habits
• No use of medication
• VO2-max for trained subjects above 50 mL/min/kg
• VO2-max for untrained subjects below 40 mL/min/kg

Exclusion Criteria:

• Any medical condition requiring treatment and/or medication use OR diminishing exercise tolerance
• Alcohol consumption of more than 20 g per day (± 2 units)
• Unstable body weight (weight gain or loss > 3 kg in the past three months)
• Participation in another biomedical study within 1 month prior to the screening visit

• Contraindications for MRI scan:

  • Central nervous system aneurysm clips
  • Implanted neural stimulator
  • Implanted cardiac pacemaker of defibrillator
  • Cochlear implant
  • Iron- containing corpora aliena in the eye or brain
  • Hearing aids and artificial (heart) valves which is contraindicated for MRS
• Subjects, who do not want to be informed about unexpected medical findings cannot participate in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: NON_RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
OTHER: Endurance Trained Subjects	Other: Cycling; 30 minutes of cycling at 50% of predetermined maximal performance
OTHER: Untrained Subjects	Other: Cycling; 30 minutes of cycling at 50% of predetermined maximal performance

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Exercise-induced changes in acetylcarnitine concentrations and dynamics of acetylcarnitine restoration after exercise	Acetylcarnitine concentration measured with Proton Magnetic Resonance Spectroscopy (1H-MRS)	During 30 minutes prior to the exercise and for 30 minutes after exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Substrate oxidation	Measured with indirect calorimetry	Measured during the 30 minutes of exercise
Blood plasma free fatty acids	Blood sample of 10 mL	At the start and at the end of 30 minutes of exercise
Blood plasma triglycerides	Blood sample of 10 mL	At the start and at the end of 30 minutes of exercise
Blood plasma glucose	Blood sample of 10 mL	At the start and at the end of 30 minutes of exercise

Collaborators and Investigators

• Sponsor: Maastricht University Medical Center
• Investigators: Principal Investigator: Vera B. Schrauwen-Hinderling, PhD., Maastricht University Medical Center

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (ACTUAL): March 1, 2014
• Study Completion (ACTUAL): June 1, 2014

Study Registration Dates

• First Submitted: March 7, 2012
• First Submitted That Met QC Criteria: March 12, 2012
• First Posted (ESTIMATE): March 14, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): September 20, 2016
• Last Update Submitted That Met QC Criteria: September 19, 2016
• Last Verified: July 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 11-2-069