ObesityNCT04700800
Regulation of Muscle Protein Phenotype in Humans With Obesity
A study testing Exercise in people with Obesity, run by Mayo Clinic at 1 site in United States.
Trial summary
A hallmark of muscle changes in obesity is an altered muscle fiber type profile, characterized by a reduced proportion of Type I fibers - a shift associated with adverse obesity-related health outcomes. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- Exercise
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Oct 2021to 2 Oct 2024
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- ability to sign informed consent form
- body mass index (BMI), 18-26 kg/m2 (lean subjects), 32-50 kg/m2 (subjects with obesity)
Who cannot join
- prescription or over-the-counter medication
- supplements known to affect protein metabolism (i.e., amino acids, protein, omega-3 fatty acids)
- diabetes
- acute illness
- liver disease
- uncontrolled metabolic disease, including renal disease
Show all 16Show fewer
- heart disease related to atrial fibrillation, history of syncope, limiting or unstable angina, congestive heart failure or ECG documented abnormalities
- low hemoglobin or hematocrit
- use of anabolic steroids or corticosteroids (within 3 months)
- not classified as inactive/sedentary based on the Stanford Brief Activity Survey and accelerometry data
- participation in a weight-loss regimen
- extreme dietary practices (i.e., vegan, vegetarian)
- smoking
- pregnancy
- gastro-intestinal surgery
- any other condition or event considered exclusionary by the PI and the study physician.
Trial locations and contacts
1 site in 1 country.
About this study
A hallmark of muscle changes in obesity is an altered muscle fiber type profile, characterized by a reduced proportion of Type I fibers - a shift associated with adverse obesity-related health outcomes. This alteration can be linked to changes in the expression of myosin heavy chain (MHC) protein isoforms in the skeletal muscle of individuals with obesity. The investigators aim to modulate the metabolism of muscle MHC isoforms to uncover the biological mechanisms underlying this disrupted expression pattern in muscle of humans with obesity.
Read the detailed description
Humans with obesity have typically lower proportion of Type I muscle fibers in skeletal muscle. These fiber types, known for their high capacity for glucose uptake, have also greater sensitivity to fuel metabolism compared with Type II fibers, even within the adverse metabolic environment of obesity. Altered expression of skeletal muscle myosin heavy chain (MHC) protein isoforms, molecular marker of fiber types, may explain this shift.
This project aims to uncover the biological mechanisms sustaining disrupted MHC protein metabolism in the skeletal muscle of individuals with obesity. The investigators will compare overall protein metabolism between humans with obesity and lean controls, with a specific focus on MHC isoforms. They will assess MHC isoform gene expression, associated molecular regulators, and synthesis rates of the MHC isoforms involved in muscle fiber programming. Acute aerobic exercise and elevated plasma amino acids will be used as experimental tools to target transcriptional and translational processes related to MHC gene expression. The findings are expected to reveal mechanisms responsible for the unfavorable fiber type profile observed in the skeletal muscle of humans with obesity.
- Conditions
- Obesity
- Being tested
- Exercise
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ExerciseOther
Exercise at 65% of heart rate reserve
| Study group | Role | What they receive |
|---|---|---|
| Subjects with obesity | Experimental | Exercise followed by infusion of amino acids Receives: Other: Exercise |
| Lean Subjects | Active comparator | Exercise followed by infusion of amino acids Receives: Other: Exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Whole-Muscle Protein Synthesis
Protein synthesis rates in whole muscle were quantified as the fractional synthesis rate (FSR), expressed as %/hour - representing the percentage of the entire muscle protein pool newly synthesized per hour.
Protein synthesis rates were determined by continuous infusion of a stable isotope-labeled amino acid tracer, followed by measurement of tracer incorporation into the muscle proteins over time.
Changes in FSR from baseline were evaluated in response to combined exercise and amino acid infusion.
Measured: 9 Hours
Synthesis Rates of the Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx)
Synthesis rates of the myosin heavy chain protein isoforms were quantified as the fractional synthesis rate (FSR), expressed as %/hour - representing the percentage of each of the three myosin heavy chain isoform protein pool newly synthesized per hour.
Protein synthesis rates were determined by continuous infusion of a stable isotope-labeled amino acid tracer, followed by measurement of tracer incorporation into each of the three myosin heavy chain isoform protein
Changes in FSR from baseline were evaluated in response to combined exercise and amino acid infusion.
Measured: 9 Hours
Messenger RNA (mRNA) Expression of Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx)
Messenger RNA (mRNA) expressions of the myosin heavy chain isoforms were determined by measuring the abundance of the three specific transcripts of the myosin heavy chain isoforms.
mRNA was measured using quantitative reverse transcription PCR (qRT-PCR).
Changes in mRNA expression from baseline were evaluated in response to combined exercise and amino acid infusion.
Measured: 9 Hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2021
- Study start7 Oct 2021
- Primary completion2 Oct 2024
- Study completion2 Oct 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by Mayo ClinicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 48 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mayo Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lori R. Roust, Mayo Clinic
- Investigators
- Lori R Roust, MD, Principal investigator, Mayo ClinicChristos S Katsanos, PhD, Principal investigator, Arizona State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04700800
- Sponsor's protocol ID
- 20-003294
- Other IDs
- R01DK123441
- Status last verified
- Sep 2025
- First submitted
- 21 Dec 2020
- Last updated
- 5 Nov 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Regulation of Muscle Protein Phenotype in Humans With Obesity
- ClinicalTrials.gov ID
- NCT04700800
- Acronym / sponsor ID
- 20-003294
- Conditions
- Obesity
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 48 participants (actual)
- Lead sponsor
- Mayo ClinicUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 7 Oct 2021 (actual)
- Primary completion
- 2 Oct 2024 (actual)
- Study completion
- 2 Oct 2024 (actual)
- First posted
- 8 Jan 2021 (actual)
- Results
- Posted 5 Nov 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A hallmark of muscle changes in obesity is an altered muscle fiber type profile, characterized by a reduced proportion of Type I fibers - a shift associated with adverse obesity-related health outcomes. This alteration can be linked to changes in the expression of myosin heavy chain (MHC) protein isoforms in the skeletal muscle of individuals with obesity. The investigators aim to modulate the metabolism of muscle MHC isoforms to uncover the biological mechanisms underlying this disrupted expression pattern in muscle of humans with obesity.
Detailed description
Humans with obesity have typically lower proportion of Type I muscle fibers in skeletal muscle. These fiber types, known for their high capacity for glucose uptake, have also greater sensitivity to fuel metabolism compared with Type II fibers, even within the adverse metabolic environment of obesity. Altered expression of skeletal muscle myosin heavy chain (MHC) protein isoforms, molecular marker of fiber types, may explain this shift.
This project aims to uncover the biological mechanisms sustaining disrupted MHC protein metabolism in the skeletal muscle of individuals with obesity. The investigators will compare overall protein metabolism between humans with obesity and lean controls, with a specific focus on MHC isoforms. They will assess MHC isoform gene expression, associated molecular regulators, and synthesis rates of the MHC isoforms involved in muscle fiber programming. Acute aerobic exercise and elevated plasma amino acids will be used as experimental tools to target transcriptional and translational processes related to MHC gene expression. The findings are expected to reveal mechanisms responsible for the unfavorable fiber type profile observed in the skeletal muscle of humans with obesity.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Subjects with obesity | Experimental | Other: ExerciseExercise followed by infusion of amino acids |
| Lean Subjects | Active comparator | Other: ExerciseExercise followed by infusion of amino acids |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- ability to sign informed consent form
- body mass index (BMI), 18-26 kg/m2 (lean subjects), 32-50 kg/m2 (subjects with obesity)
Key exclusion criteria (16 listed)
- prescription or over-the-counter medication
- supplements known to affect protein metabolism (i.e., amino acids, protein, omega-3 fatty acids)
- diabetes
- acute illness
- liver disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ExerciseExercise at 65% of heart rate reserve | Other | Lean Subjects, Subjects with obesity |
Primary outcome
Whole-Muscle Protein Synthesis
Time frame: 9 Hours
Protein synthesis rates in whole muscle were quantified as the fractional synthesis rate (FSR), expressed as %/hour - representing the percentage of the entire muscle protein pool newly synthesized per hour. Protein synthesis rates were determined by continuous infusion of a stable isotope-labeled amino acid tracer, followed by measurement of tracer incorporation into the muscle proteins over time. Changes in FSR from baseline were evaluated in response to combined exercise and amino acid infusion.
Synthesis Rates of the Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx)
Time frame: 9 Hours
Synthesis rates of the myosin heavy chain protein isoforms were quantified as the fractional synthesis rate (FSR), expressed as %/hour - representing the percentage of each of the three myosin heavy chain isoform protein pool newly synthesized per hour. Protein synthesis rates were determined by continuous infusion of a stable isotope-labeled amino acid tracer, followed by measurement of tracer incorporation into each of the three myosin heavy chain isoform protein Changes in FSR from baseline were evaluated in response to combined exercise and amino acid infusion.
Messenger RNA (mRNA) Expression of Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx)
Time frame: 9 Hours
Messenger RNA (mRNA) expressions of the myosin heavy chain isoforms were determined by measuring the abundance of the three specific transcripts of the myosin heavy chain isoforms. mRNA was measured using quantitative reverse transcription PCR (qRT-PCR). Changes in mRNA expression from baseline were evaluated in response to combined exercise and amino acid infusion.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lori R Roust, MD principal investigator
Mayo Clinic
Christos S Katsanos, PhD principal investigator
Arizona State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Exercise in people with Obesity, run by Mayo Clinic at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 5 Nov 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Whole-Muscle Protein Synthesis (time frame: 9 Hours). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Nov 2025.