Upper Limit of Leucine Intake in Adults

NCT00972582 | Completed Phase 1

• 1 other identifier: 1000012066
• Study Type: interventional
• Target: 5
• Locations: 1 country
• Sites: 1

Brief Summary

When dietary amino acid supplements are consumed by humans they are normally in addition to their normal daily requirements. The investigators' laboratory played a leading role in defining the estimated average requirement (EAR) and the recommended dietary intake for the "essential" amino acids (Dietary Reference Intakes 2005). The other important but less well studied component of Dietary Reference Intakes (DRI) is - What is a safe upper limit of intake? The investigators now propose to determine the safe upper limits of the dietary essential amino acids. The recently published DRI (2005) defines the Tolerable Upper Intake Level (UL) as 'the highest average daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population.' As intake increases above the UL, the potential risk of adverse effects may increase'. In this proposal, the investigators define a novel method to define the safe upper limit where the 'maximum oxidative potential' of an amino acid identifies the 'metabolic limit' to dispose the amino acid. Intakes of amino acid above this level will increase the potential for adverse effects to appear.

Conditions

Healthy

Keywords

leucine intake; tolerable upper limit; adults; amino acid supplements; Excessive Leucine Intake

Outcome Measures

Primary Outcomes (1)

• Breath carbon dioxide production

  Study Visits 1-7 (-45min,-30min,-15min, +2.5hrs, +3hrs, +3.5Hrs +4hrs)

Secondary Outcomes (3)

• Plasma

  Study Visits 1-7 (Hourly)

• Urine

  Study Visits 1-7 (8hr timepoint)

• VCO2

  Study Visits 1-7 (after 5hr meal)

Study Arms (1)

Leucine

EXPERIMENTAL

Dietary Supplement: Leucine Increase

Interventions

Leucine Increase DIETARY_SUPPLEMENT

Graded stepwise increases in leucine intakes (50, 250, 500, 750, 1000, 1250 and 1500mg/kg/day)

Leucine

Eligibility Criteria

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

You may qualify if:

• Male
• years old

You may not qualify if:

• Report a recent history of sudden weight loss
• Have unusual dietary habits such as chronic consumption of caffeinated beverages or alcohol
• Have any endocrine disorders
• Are currently using any prescribed medications

Sponsors & Collaborators

• The Hospital for Sick Children: lead

Study Sites (1)

The Hospital for Sick Children

Toronto, Ontario, Canada

Location

Related Publications (1)

• Elango R, Chapman K, Rafii M, Ball RO, Pencharz PB. Determination of the tolerable upper intake level of leucine in acute dietary studies in young men. Am J Clin Nutr. 2012 Oct;96(4):759-67. doi: 10.3945/ajcn.111.024471. Epub 2012 Sep 5.

  PMID: 22952178 DERIVED

Study Officials

• Paul B Pencharz, MD

  The Hospital for Sick Children, Toronto, Canada

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Emeritus Scientist

Study Record Dates

• First Submitted: September 4, 2009
• First Posted: September 7, 2009
• Study Start: May 1, 2009
• Primary Completion: February 1, 2010
• Study Completion: February 1, 2010
• Last Updated: July 29, 2013

Record last verified: 2013-07

Locations

CA (1)