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CompletedNCT02499926Updated Jul 25, 2024

Lysine Oxidation in Response to Arginine Supplementation

An interventional study of Arginine in Physiologically Healthy Adult Male Participants, sponsored by University of British Columbia. Completed at 1 site in Canada. Open to male participants aged 19 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-07-25.

Sponsored by University of British Columbia · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
5
Allocation
Not applicable
Ages
19 Years to 50 Years
Sex
Male
01

Study summary

This research study is investigating if consuming more of one amino acid (arginine) influences the digestion and absorption of another amino acid (lysine) due to competition in digestion, in a healthy adult population.

Read the detailed description

Background:

Protein is made up of building blocks called amino acids. Some amino acids, including Lysine, cannot be made in the body and must be obtained from diet, and these are called essential amino acids.

Pyridoxine dependent deficiency (PDE) is a rare condition caused by the body's inability to properly breakdown lysine. This is due to a missing enzyme, α- aminoadipic semi-aldehyde dehydrogenase (α-AASAD) also known as antiquitin (ATQ), involved in lysine breakdown. When the enzyme is missing and/or not functioning properly, it increases the level of byproducts of lysine breakdown that may result in seizures babies and young children and affect brain development. As with many other similar conditions, a low lysine diet may be helpful for some patients, but can pose a significant burden on the patient and the families.

More recently, animal experiments have shown that the body's ability to absorb lysine from the diet can be altered by adding more of another "competitive" amino acid, in this case, arginine. This is because lysine and arginine share the same transport system in the body.

Therefore, the current study is designed to describe the application of 13C-lysine to explore the changes in lysine breakdown caused by varying (graded) amounts of arginine supplementation in young adult male participants.

Study design:

Two adult male subjects aged 19-50 y will be recruited to participate in 6 graded doses of arginine intakes, in addition to a test diet which will provide the lysine at normal intake of 110mg/kg/d. Lysine intake levels, will be determined based on subject age and body weight and will remain constant for the entire study period. The recommended dietary protein intake (DRI) will be maintained throughout the study.

A thorough pre-study assessment will be performed and all subjects will be screened by questionnaire for chronic diseases, physical activity and dietary habits. Lean body mass or skeletal muscle mass (Bioelectrical impedance Analysis) will be measured. Subjects will be ensured to be free of chronic diseases.

Arginine Test Intakes:

Graded arginine excess intake will start at 50mg/kg/d on study day 1 followed by 100 mg/kg/d on study day 2 till the level reaches 300mg/kg/d on study day 6.

The arginine test intakes will be provided in the form of protein shakes containing a stable isotope, and then oxidation of this isotope will be measured to determine whether arginine that will competitively inhibit lysine uptake.

To measure how the the body responds to the test diet we will collect seven breath samples, two urine samples and one blood sample during each study day.

02

Conditions studied

  • Physiologically Healthy Adult Male Participants
03

In context

Lead sponsor

University of British Columbia is the lead sponsor of 1,309 studies on the registry; 253 are open to participants now.

Of its 6 completed or terminated interventional studies of FDA-regulated products, 1 (17%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
19 Years to 50 Years
Sexes eligible
Male
Accepts healthy volunteers
Yes

Inclusion criteria

  • You are 19 to 50 years-of-age
  • Male
  • Classified as normal body weight and BMI (18.5-25 kg/m2)
  • Free of any concurrent illness (cold, flu, vomiting etc.)
  • Not be claustrophobic (we will place a clear hood, which can easily be removed, over your head for approximately 20 min to measure your energy expenditure).
  • Not be enrolled in any other research studies (as this may affect our study results)

Exclusion criteria

Exclusion Criteria:

You are not in good health or have a metabolic, neurological, genetic, or immune disorder, including diabetes and hypertension

  • You are classified as underweight (\<18.5 kg/m2), overweight (25-30 kg/m2), or obese (>30 kg/m2) using the BMI classification
  • You are allergic to milk, eggs and egg protein
  • You are claustrophobic (we will place a clear hood, which can easily be removed, over your head for approximately 20 min to measure your energy expenditure)
  • You are currently enrolled in other research studies (as this may affect our study results)
05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
5 participants (actual)

Study arms

  • Experimental
    Dietary supplement: Arginine

    Graded arginine excess intake

    Dietary Supplement: Arginine

Interventions

  • Dietary supplementArginine

    Graded arginine excess intake will start at 50mg/kg/d on study day 1 followed by 100 mg/kg/d on study day 2 till the level reaches 300mg/kg/d on study day 6. Consisting of oral consumption of eight hourly experimental meals per study day - Includes 4 tracer free experimental meals containing a mixture of free amino acids, calories from a flavored liquid and protein free cookies and 4- labeled amino acid experimental meals.

06

What researchers measure

Primary outcomes

  1. 13CO2 production

    Urine, plasma and breath samples will be collected during the study to measure the rate of oxidation of tracer with graded intake of arginine

    Time frame: 8 hours (1 study day)

07

Study locations

1 site
  • BC Children;s Hospital Research Institute, University of British Columbia
    Vancouver, British Columbia V5Z4H4, Canada
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 25, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02499926
Lead sponsor
University of British Columbia
Responsible party
Rajavel Elango, PhD (Assistant Professor, University of British Columbia) — Principal investigator
First posted
Jul 16, 2015
Start date
Jul 2015
Primary completion
Dec 2017
Completion
Jan 12, 2024
Last update
Jul 25, 2024

Study contacts

Rajavel Elango, PhD
principal investigator · University of British Columbia

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Jul 2024. You cannot join it, but the record below documents what was studied.

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