Oral 'Breath Test' to Measure Anabolic Sensitivity in Young and Older Adults at Different Activity Levels

NCT ID: NCT05216809

Last Updated: 2023-11-09

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 32 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-02-01
• Study Completion Date: 2024-03-31

Brief Summary

Recent work in the investigators laboratory has examined the ability of a non-invasive 13CO2 breath-test to assess differences in amino acid oxidation rates and net balance in young healthy males following protein feeding and resistance exercise. The investigators aim to test the efficacy of this non-invasive 13CO2 breath-test to assess for differences in anabolic sensitivity between young and older adults following an acute period of habitual and reduced physical activity.

Detailed Description

Aging is associated with a phenomenon known as anabolic resistance, whereby individuals are less responsive to anabolic stimuli (i.e., resistance exercise, dietary protein ingestion). Mild and severe reductions in physical activity are also known to play a key role in the emergence of anabolic resistance. Therefore, the purpose of this study is to investigate the ability of a non-invasive 13CO2 breath-test to assess differences in whole-body leucine oxidation and leucine net balance between younger and older individuals under conditions of habitual activity and following a period of reduced activity/step-reduction. In this manner, the ability of the methodology to distinguish anabolic sensitivity between young and older adult populations will be assessed.

Methods:

Total participant time commitment will span over 4 sessional dates:

Session 1 - Introduction Interested participants will be recruited to engage in a video conference call to undergo an introductory session. Participants will be provided with a comprehensive introduction to the study which will explain the research objectives, conduct, and associated risks. Participants will provide informed consent prior to the collection of any study information (i.e., anthropometrics and habitual activity levels). Eligibility will also be screened for at this time.

Session 2 - Body Composition Assessment Participants will consume a bolus of deuterium oxide (D2O) and provide saliva samples in order to estimate fat-free mass.

The remainder of the study will consist of seven consecutive days, wherein Phase 1 (Habitual Activity) will be subsequently followed by Phase 2 (Step-Reduction).

Phase 1 - Habitual Activity (Days 1-3) Participants will be asked to engage in their habitual activity pattern (> 7000 steps/day) while wearing an accelerometer and pedometer. Participants will be further instructed to maintain their normal dietary patterns and to track their diets over the course of these three days using diet logs.

Session 3 - Habitual Activity Metabolic Trial (Day 4) On the morning of the fourth day, following three days of habitual activity, participants will be subjected to the non-invasive 13CO2 breath-test to assess for whole-body leucine oxidation and net balance. This date will also serve as a lead-in to the subsequent Phase 2.

Phase 2 - Step-Reduction (Days 4-6) Participants will be asked to maintain their normal dietary patterns and track their dietary intake, but will need to adhere to a reduced daily step count (<2000 steps/day). Accelerometers and pedometers will be worn again during this period.

Session 4 - Step-Reduction Metabolic Trial (Day 7) On the morning of the 7th day, following three days of reduced daily step-count, participants will be subjected again to the non-invasive 13CO2 breath-test to assess for whole-body leucine oxidation and net balance. Ultimately, this will allow us to determine whether 3-days of reduced step-count will impart any changes on anabolic sensitivity.

For each metabolic trial, two urine samples (baseline and pooled enriched) will be collected, in addition to breath samples collected over a 6-hour post-prandial period at 20-30 minute intervals. These biological samples will be used to measure tracer excretion and oxidation, allowing us to determine rates of protein metabolism.

Conditions

Sedentary Behavior; Aging; Sarcopenia; Amino Acids; Dietary Protein

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Young Adults

Equal sex distribution (10M/10F); ages 18-35 years old.

Group Type: ACTIVE_COMPARATOR

Habitual Physical Activity

Intervention Type: BEHAVIORAL

Participants will maintain habitual levels of physical activity (inclusive of structured physical activity). Participants will be required to maintain \>7,000 steps/day.

Step-Reduction

Intervention Type: BEHAVIORAL

Participants will be required to reduce their daily step-counts to \<2,000 steps/day. Further, they will be required to refrain from structured physical activity.

Older Adults

Equal sex distribution (6M/6F); ages 60-80 years old.

Group Type: ACTIVE_COMPARATOR

Habitual Physical Activity

Intervention Type: BEHAVIORAL

Participants will maintain habitual levels of physical activity (inclusive of structured physical activity). Participants will be required to maintain \>7,000 steps/day.

Step-Reduction

Intervention Type: BEHAVIORAL

Participants will be required to reduce their daily step-counts to \<2,000 steps/day. Further, they will be required to refrain from structured physical activity.

Interventions

Habitual Physical Activity

Participants will maintain habitual levels of physical activity (inclusive of structured physical activity). Participants will be required to maintain \>7,000 steps/day.

Intervention Type: BEHAVIORAL

Step-Reduction

Participants will be required to reduce their daily step-counts to \<2,000 steps/day. Further, they will be required to refrain from structured physical activity.

Intervention Type: BEHAVIORAL

Other Intervention Names

Free-Living Activity; Reduced Physical Activity

Eligibility Criteria

Inclusion Criteria

• Healthy young (age: 18-35 years) or older (age: 60-80 years) adults
• Average daily step-count >7,000/day
• BMI between normal to overweight (18.5-29.9 kg/m2)

Exclusion Criteria

• Regular use of nonsteroidal anti-inflammatory drugs (with the exception of daily low-dose aspirin)
• Use of anticoagulants
• Use of a walker, cane, or assistive walking device
• Current or recently remised cancer
• Infectious or gastrointestinal disease
• Inability to comply with study protocol (e.g., >2,000 steps/day during Step-Reduction Phase)
• Regular tobacco use
• Self-reported illicit drug use (e.g. growth hormone, testosterone, etc.)
• Diagnosed chronic illness (e.g. type 2 diabetes, heart disease, thyroid disease)
• Pregnant
• Hormonal Replacement Therapy

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Toronto

OTHER

Sponsor Role: lead

Responsible Party

Daniel Moore

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Daniel Moore, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Toronto

Hugo JW Fung, PhD (c)

Role: STUDY_DIRECTOR

University of Toronto

Locations

Goldring Centre for High Performance Sport at the University of Toronto

Toronto, Ontario, Canada

Site Status: RECRUITING

Countries

Canada

Central Contacts

Daniel R Moore, PhD

Role: CONTACT

dr.moore@utoronto.ca

4169464088

Matthew Lees, PhD

Role: CONTACT

matthew.lees@utoronto.ca

Facility Contacts

Daniel R Moore, PhD

Role: primary

dr.moore@utoronto.ca

416-946-4088

Hugo Fung, MSc

Role: backup

hugojernwai.fung@mail.utoronto.ca

Other Identifiers

ARBT

Identifier Type: -

Identifier Source: org_study_id