AzTrials
AzTrials

AgingNCT02371278

Leucine Co-ingestion and Myofibrillar Protein Synthesis in Older Adults

A study testing Leucine in people with Aging and Sarcopenia, run by McMaster University at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

The loss of muscle mass with aging is associated with a dysregulation of muscle protein synthesis (MPS) that is generally characterized by a suppressed MPS response to protein ingestion. Read more about this study

Who is it for?
Ages 65 to 85 years, men onlyHealthy volunteers can take part
Conditions the study is for
Aging, Sarcopenia
What is being tested?
Leucine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
20 participants
Where
1 siteCanada
Study dates
May 2015to Oct 2015
Phase
Interventional
Are there results?
None posted in the registry

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 65 to 85 years
  • Men only
  • Healthy volunteers accepted
  • Older adult

Who may be able to join

  • Body mass index (BMI) between 20-35 kg/m2
  • Non-smokers

Who cannot join

  • Diabetes mellitus, prediabetes and the metabolic syndrome
  • Cardiovascular disease
  • Neuromuscular problems or muscle wasting diseases
  • Renal disease
  • Gastrointestinal disease
  • Musculoskeletal conditions such as rheumatoid arthritis or osteoarthritis
Show all 12Show fewer
  • Infectious disease
  • Cancer
  • Significant body mass loss in the 1 month period prior to the study
  • Vegetarianism
  • Use of medications known to interfere with muscle metabolism (i.e. beta-blockers, high dose non-steroidal anti-inflammatory drugs, corticosteroids, hormone replacement therapy, antiarrhythmic drugs, warfarin, prescription strength acne medications, oral hypoglycaemic agents and insulin)
  • Regular resistance training or daily step counts >9,000 or <3,500

Trial locations and contacts

1 site in 1 country.

Canada1 site
  • McMaster University

    Hamilton, Ontario, L8S 4K1

Other trials in Canada

About this study

Official title: Influence of Leucine Co-ingestion With Mixed Meals on Integrative Myofibrillar Protein Synthesis in Older Adults

The loss of muscle mass with aging is associated with a dysregulation of muscle protein synthesis (MPS) that is generally characterized by a suppressed MPS response to protein ingestion. This 'anabolic resistance' to protein feeding can be overcome with the ingestion of larger protein servings (~0.4g/kg/meal, equivalent to ~ 30 - 40g/meal); however, older adults would likely find it challenging to consume such quantities of protein on a per meal basis.

The amino acid leucine has a unique role as a key 'activator' of MPS. Some research shows that increasing the leucine content of a suboptimal dose of a protein supplement can enhance the MPS response in older adults. However it is currently unknown whether the co-ingestion of leucine with normal, mixed meals can increase MPS. Furthermore, it has been suggested that leucine supplementation may only benefit older adults consuming suboptimal daily protein intakes. Therefore, the purpose of the current study is to examine the impact of leucine co-ingestion with mixed macronutrient meals on the myofibrillar protein synthetic response in older men consuming daily protein intakes at or below the current recommendations. A further objective is to determine whether the myofibrillar protein synthetic response to a session of resistance exercise is enhanced by leucine supplementation with meals. The investigators hypothesize that, in both the exercised and non-exercised condition, leucine co-ingestion at meals will enhance integrative myofibrillar protein synthesis in older adults consuming lower daily protein intakes, but will not augment MPS in those consuming higher daily protein. The investigators further hypothesize that the influence of leucine supplementation on MPS will be greater in the exercise condition than the non-exercise condition.

Read the detailed description

At baseline, participants will be asked to wear a pedometer and to complete a physical activity and a weighed food record for 3 days. Resting energy expenditure (indirect calorimetry), body weight and body composition (DEXA) will be assessed in the fasted state. A strength test will be conducted to determine 1 repetition maximum (1-RM) and the maximum load that each participant can lift for 15 - 24 repetitions using a seated leg extension machine. Participants will then be randomized to one of two groups matched for age, activity level and BMI: higher (1.2 g/kg/d) or lower daily protein (0.8 g/kg/d). Participants will then commence a 9 day controlled diet (day -3 to 6) designed to meet energy requirements for weight maintenance and to provide a daily protein intake according to each participant's group allocation (i.e. 0.8 or 1.2 g/kg/d).

All participants will be provided with flavored, supplemental beverages (Infinit Nutrition, Windsor, Ontario) and will be instructed to consume one beverage half way through each meal from day 0 - 5. Individual servings of the supplement will be packaged into a ziplocked pouch by Infinit Nutrition in power form. Participants will be required to add water to the power at home. During day 0 - 2 (unsupplemented period) the beverage will be a placebo (maltodextrin and sucrose), and during day 3 - 5 (leucine supplementation period) the beverage will contain crystalline leucine (5 g) with sucrose for flavour. The beverages will be provided in a single-blind manner, energy-matched and will be similar in odour, color, and taste. Participants will also be blinded to their group allocation.

Aminoacidemia, insulinemia and glycaemia will be determined in response to breakfast, lunch and dinner ingestion during the unsupplemented (day 2) and leucine supplemented (day 5) periods. During each of these blood sampling trials blood samples will be obtained immediately before and 20, 40, 60, 90, 120, 180, 240 min following the ingestion of each meal (total of 25 x 4ml blood samples per participant per trial).

Integrative MPS will be measured in the exercised and non-exercised leg over the unsupplemented (day 0 - 3) period and leucine supplemented (day 3 - 6) period using orally ingested deuterated water (D20) and muscle biopsies obtained from the vastus lateralis on days 0, 3 and 6. Participants will report to the laboratory in the fasted state on day 0 and, following a muscle biopsy from the vastus lateralis and saliva sample, participants will consume a single 100 ml oral bolus of D20 at approximately 0900. Immediately following the D20 bolus participants will perform a bout of unilateral leg extension exercise (3 sets to volitional failure at the maximum load they can lift for 15-24 repetitions (~40-50% 1-RM)). On day 3 participants will perform an identical resistance exercise session with the exception that repetitions will be clamped at the number achieved on day 0. Following both exercise sessions participants will consume their individualized breakfast (with the placebo beverage on day 0 and with the leucine beverage on day 3) in the laboratory before returning home. Bilateral muscle biopsies will be obtained prior to the exercise on day 3 (end of unsupplemented period) and on day 6 (end of leucine supplemented period). Total body water deuterium enrichment can be used as a surrogate for plasma alanine labelling and will be determined from saliva swabs collected by the participant every morning at 0900. Participants will be instructed to not eat or drink anything for 30 min before saliva sampling and samples will be stored in the participant's freezer before their next visit to the laboratory.

Conditions
Aging, Sarcopenia
Being tested
Leucine, Placebo
Keywords
Leucine, Protein, Diet, Muscle protein synthesis
Medical subject headings
Sarcopenia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • LeucineDietary supplement

    5 g leucine with sucrose and maltodextrin

  • PlaceboDietary supplement

    5 g glycine with sucrose and maltodextrin

Study groups in NCT02371278
Study groupRoleWhat they receive
Higher daily proteinOtherDiets will provide protein intakes of 1.2 g/kg/d. Placebo with meals for 3 days, and leucine with meals for 3 days.
Receives: Dietary Supplement: Leucine; Dietary Supplement: Placebo
Lower daily proteinOtherDiets will provide protein intakes of 0.8 g/kg/d. Placebo with meals for 3 days, and leucine with meals for 3 days.
Receives: Dietary Supplement: Leucine; Dietary Supplement: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Myofibrillar protein fractional synthetic rate

    The incorporation of a stable isotope (deuterium) into muscle tissue will allow for the determination of fractional synthetic rate, which is indicative of muscle protein synthesis.

    Measured: 3 days

Secondary outcomes (3)
  1. Aminoacidemia in response to daily meals with and without leucine supplementation

    Measured: 3 days

  2. Glycaemia in response to daily meals with and without leucine supplementation

    Measured: 3 days

  3. Insulinemia in response to daily meals with and without leucine supplementation

    Measured: 3 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Feb 2015 (estimated)
  2. Study startMay 2015
  3. Primary completionOct 2015
  4. Study completionOct 2015

Resources

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
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
20 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02371278
Sponsor's protocol ID
LEU-MEALS-2015
Status last verified
Mar 2016
First submitted
13 Feb 2015
Last updated
16 Mar 2016
Results posted
No
Data monitoring committee
No

Publications

  • Murphy CH, Saddler NI, Devries MC, McGlory C, Baker SK, Phillips SM. Leucine supplementation enhances integrative myofibrillar protein synthesis in free-living older men consuming lower- and higher-protein diets: a parallel-group crossover study. Am J Clin Nutr. 2016 Dec;104(6):1594-1606. doi: 10.3945/ajcn.116.136424. Epub 2016 Nov 9.

    PubMed 27935521

Questions about this trial

What is this clinical trial studying?

A study testing Leucine in people with Aging and Sarcopenia, run by McMaster University at 1 site in Canada.

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 12 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 16 Mar 2016. 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 Canada. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Myofibrillar protein fractional synthetic rate (time frame: 3 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02371278, which also lists 1 linked publication.

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 16 Mar 2016.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in