Re-evaluation of the Muscle-full Effect During Continuously Elevated Amino Acid Availability in Healthy Young Males

NCT06721026 | Not Yet Recruiting DMC

• 1 other identifier: METC24-028
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

Muscle tissue consists of proteins. These proteins are built up of a collection of smaller building blocks: amino acids. When protein is consumed, it gets digested and absorbed into the blood. The body can use these amino acids, by taking them up from thecirculation. By consuming sufficient protein through our diet, we ensure that the body is provided with enough amino acids to enable muscle protein building. Sufficient muscle protein synthesis is important for maintaining muscle function and strength. Previous research has shown that when 20 to 25g of protein is eaten, muscle protein synthesis is maximized. It is therefore recommended to eat 20g of protein per meal. However, it is currently unclear what happens to muscle protein synthesis rates if multiple meals are eaten. When multiple meals are consumed, amino acids appear in the circulation for prolonged period of time. Theoretically, when there are a high amino acid concentrations in the blood, muscle protein synthesis rates will increase. Contrary to this theory, a study more than 20 years ago showed otherwise. It was observed that muscle protein synthesis rates are only elevated for2 hours afterwhich they decrease again. This phenomenon was referred to as the "muscle-full" effect. Because this phenomenon is in contrast with more previous studies, the objective is to replicate that study. This is important so that nutritional advice for healthy, but also clinical populations in the future can be improved.

Conditions

Muscle Protein Synthesis

Keywords

amino acid infusion; tracer methodology; muscle biopsy

Outcome Measures

Primary Outcomes (1)

• Muscle protein synthesis during continuous elevated plasma amino acid avaialbility in healthy young males

  The primary endpoint is muscle protein synthesis rates (in %/h) over the full assessment period (8 h) as determined with contemporary stable isotope tracer methodology combined with repeated blood and muscle sampling. Muscle protein synthesis are calculated using plasma as precursor pool and the tracer enrichment in the muscle (measured with UPLC and GC-IRMS).

  8 hours

Secondary Outcomes (3)

• Basal muscle protein synthesis rates

  3 hours

• Whole-body protein kinetics

  8 hours

• Whole-body protein metabolism

  8 hours

Study Arms (1)

Continuous amino acid infusion

EXPERIMENTAL

Tracer infusions combined with infusion of a mixture of amino acids

Other: Continuous intravenous stable isotope amino acid tracer infusion; Other: Amino acid infusion

Interventions

Continuous intravenous stable isotope amino acid tracer infusion OTHER

During the single 12 h trial day, a primed continuous stable isotope infusion will run in order to assess muscle protein synthesis in the basal (4 h) and post-prandial (8 h) state.

Continuous amino acid infusion

Amino acid infusion OTHER

In order to assess muscle protein synthesis rates during continuous elevated plasma amino acid availability, the amino acid infusion solution Vamin®14 EF will be used. Vamin® 14EF contains 85g amino acids per liter and will be administered in the post-prandial period for 8 hours to ensure a constant rate of amino acid infusion over the full assessment period of the primary outcome measure.

Continuous amino acid infusion

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male sex
• Aged between 18 - 35 years
• Healthy (assessed based on routine medical questionnaire)
• BMI between 18.5 - 30 kg/m2

You may not qualify if:

• A potential subject who meets any of the following criteria will be excluded from participation in this study:
• Smoking
• Involved in progressive exercise training
• A history of neuromuscular problems
• Use of anticoagulants
• Recent (\<12 months) participation in amino acid tracer (L-\[ring-13C6\] phenylalanineand L-\[3,5-2H2\]-tyrosine) studies
• Use of medication known to affect (muscle) protein metabolism (e.g. corticosteroids, non-steroidal anti-inflammatory drugs, acne medication)
• Phenylketonuria
• Diagnosed with or history of liver damage
• Diagnosed with or history of severe kidney damage and/or malfunction
• Diagnosed with inability to break down amino acids

Sponsors & Collaborators

• Maastricht University Medical Center: lead

Study Sites (1)

Maastricht University Medical Centre+

Maastricht, Limburg, 6229ER, Netherlands

Location

Study Officials

• Luc van Loon, PhD

  Maastricht University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Luc van Loon, PhD

CONTACT

0031433881743; l.vanloon@maastrichtuniversity.nl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Cross-sectional, non-therapeutic, intervention study

Study Record Dates

• First Submitted: December 3, 2024
• First Posted: December 6, 2024
• Study Start: March 1, 2025
• Primary Completion: December 31, 2025
• Study Completion: February 1, 2026
• Last Updated: December 13, 2024

Record last verified: 2024-12

Locations

NL (1)