Trial Outcomes & Findings for Regulation of Muscle Protein Phenotype in Humans With Obesity (NCT NCT04700800)

Last Updated: 2025-11-05

Results Overview

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.

Recruitment status

COMPLETED

Study phase

Target enrollment

48 participants

Primary outcome timeframe

9 Hours

Results posted on

2025-11-05

Participant Flow

A total of 48 participants signed informed consent.

Of the participants that signed the consent form, 10 were screen failures, 11 withdrew, 4 declined participation, and 1 was enrolled but did not proceed. Twenty-three completed the entire study with one participant had data collected as did part of the study, for a total of 22 with data collected.

Participant milestones

Participant milestones
Measure	Participants with Obesity Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean participants Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion
Overall Study STARTED	10	12
Overall Study COMPLETED	10	12
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Regulation of Muscle Protein Phenotype in Humans With Obesity

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Participants with Obesity n=10 Participants Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean paticipants n=12 Participants Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Total n=22 Participants Total of all reporting groups
Age, Continuous	30 Years STANDARD_DEVIATION 2 • n=15 Participants	29 Years STANDARD_DEVIATION 2 • n=161 Participants	29 Years STANDARD_DEVIATION 2 • n=100 Participants
Sex: Female, Male Female	6 Participants n=15 Participants	7 Participants n=161 Participants	13 Participants n=100 Participants
Sex: Female, Male Male	4 Participants n=15 Participants	5 Participants n=161 Participants	9 Participants n=100 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=15 Participants	3 Participants n=161 Participants	4 Participants n=100 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	9 Participants n=15 Participants	9 Participants n=161 Participants	18 Participants n=100 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) Asian	1 Participants n=15 Participants	1 Participants n=161 Participants	2 Participants n=100 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) Black or African American	1 Participants n=15 Participants	0 Participants n=161 Participants	1 Participants n=100 Participants
Race (NIH/OMB) White	8 Participants n=15 Participants	11 Participants n=161 Participants	19 Participants n=100 Participants
Race (NIH/OMB) More than one race	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=15 Participants	0 Participants n=161 Participants	0 Participants n=100 Participants

PRIMARY outcome

Timeframe: 9 Hours

Outcome measures

Outcome measures
Measure	Participants with Obesity n=10 Participants Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean participants n=12 Participants Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion
Whole-Muscle Protein Synthesis	0.004 %/hr Standard Deviation 0.011	0.015 %/hr Standard Deviation 0.005

PRIMARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Participants with Obesity n=10 Participants Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean participants n=12 Participants Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion
Synthesis Rates of the Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx) Myosin Heavy Chain - I (MHC-I)	0.005 %/hr Standard Deviation 0.001	0.006 %/hr Standard Deviation 0.001
Synthesis Rates of the Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx) Myosin Heavy Chain -IIa (MHC-IIa)	0.004 %/hr Standard Deviation 0.001	0.005 %/hr Standard Deviation 0.001

PRIMARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Participants with Obesity n=10 Participants Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean participants n=12 Participants Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion
Messenger RNA (mRNA) Expression of Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx) MHC-I	1.1 Arbitrary Units Standard Deviation 0.5	1.0 Arbitrary Units Standard Deviation 0.4
Messenger RNA (mRNA) Expression of Three Myosin Heavy Chain Isoforms (MHC I, MHC IIa, and MHC IIx) MHC-IIa	0.5 Arbitrary Units Standard Deviation 0.2	0.6 Arbitrary Units Standard Deviation 0.3

Adverse Events

Participants with Obesity

Serious events: 0 serious events

Other events: 2 other events

Deaths: 0 deaths

Lean participants

Serious events: 0 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Participants with Obesity n=10 participants at risk Participants with Obesity performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion	Lean participants n=12 participants at risk Healthy lean participants performing acute aerobic exercise followed by infusion of amino acids, with measurements take before and after exercise+amino acid infusion
Musculoskeletal and connective tissue disorders Numbness and soreness on the site of muscle biopsy few days after the procedure	10.0% 1/10 • Number of events 1 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)	8.3% 1/12 • Number of events 1 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)
Nervous system disorders Nauseous and/or lightheaded	0.00% 0/10 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)	25.0% 3/12 • Number of events 3 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)
Gastrointestinal disorders Numbness in mouth	0.00% 0/10 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)	8.3% 1/12 • Number of events 1 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)
Gastrointestinal disorders Unable to drink the drink provided for the oral glucose tolerance test	10.0% 1/10 • Number of events 1 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)	0.00% 0/12 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)
Musculoskeletal and connective tissue disorders Car accident outside the study procedures, preventing further participation in the study	0.00% 0/10 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)	8.3% 1/12 • Number of events 1 • Up to 6 months after enrollment in the study. Levels of adverse events were defined as: Mild, Moderate, Severe (severe would correspond to serious)

Additional Information

Lori Roust

Mayo Clinic

Phone: (602) 543-4254

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place