Nutritional Strategies to Augment the Postprandial Muscle Protein Synthetic Response to the Ingestion of a Low Dose of Protein in Middle-aged Women

Using stable isotope methodology, investigators will determine the postabsorptive and postprandial muscle protein synthetic response in 60 female adults (Age 50-79, BMI: <30 kg/m2) immediately after an acute bout of resistance exercise. Participants will be divided in to 5 groups of twelve women (n=12). Each group will receive a different protein beverage or placebo to consume following the resistance exercise training. Group 1 will consume a beverage consisting of whey protein; group 2 will consume whey protein supplemented with additional leucine; group 3 will consume whey protein supplemented with additional leucine and hydrolyzed whey peptides; group 4 will consume whey protein supplemented with additional leucine and citrulline; group 5 will just consume water. During the testing, blood and muscle samples will be collected.

Study Overview

• Status: Completed
• Conditions: Aging
• Intervention / Treatment: Behavioral: Resistance Exercise; Dietary supplement: 14 g Whey protein; Dietary supplement: 6.6 g Whey protein + 1.25 g leucine; Dietary supplement: 4 g Whey protein + 1.25 g leucine + 2.6 g Whey peptides; Dietary supplement: 6.6 g Whey protein + 1.25 g leucine + 0.8 g Citrulline; Other: Water control

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Urbana, Illinois, United States, 61801
      • Freer Hall

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• BMI <30 kg/m2
• Healthy, sedentary
• Either 20-30 years old or 50-79 years old

Exclusion Criteria:

• Tobacco use
• Allergies to milk consumption
• Unusually high protein consumption
• Vegan diet
• Allergies to antibiotics or xylocaine
• Phenylketonuria (PKU)
• Diagnosed GI tract diseases
• Arthritic conditions
• A history of neuromuscular problems
• Heart disease
• Metabolic disorders
• -Liver, kidney, or urinary disease
• Musculoskeletal problems
• Autoimmune disease
• Neurological disease
• Previous participation in amino acid tracer studies
• Predisposition to hypertrophic scarring or keloid formation
• Individuals on any medications known to affect protein metabolism (i.e. corticosteroids, non-steroidal anti-inflammatories, or prescription strength acne medications).
• Individuals using thyroid medications or other medications affecting endocrine function
• Pregnancy
• Contraindications for exercise
• BMI ≥30
• supplements that influence protein metabolism (e.g omega 3 fish oils)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Whey protein; After resistance exercise, participants aged 50-79 years will consume 14g Whey protein dissolved in 200 mL of water	Behavioral: Resistance Exercise; Participants will perform unilateral leg extension exercise immediately prior to ingestion of the experimental beverage; Dietary supplement: 14 g Whey protein
Experimental: Whey + Leucine; After resistance exercise, participants aged 50-79 years will consume 6.6 g Whey protein + 1.25 g Leucine dissolved in 200 mL of water	Behavioral: Resistance Exercise; Participants will perform unilateral leg extension exercise immediately prior to ingestion of the experimental beverage; Dietary supplement: 6.6 g Whey protein + 1.25 g leucine
Experimental: Whey + Leucine + Whey peptides; After resistance exercise, participants aged 50-79 years will consume 4 g Whey protein + 1.25 g Leucine + 2.6 g Whey peptides dissolved in 200 mL of water	Behavioral: Resistance Exercise; Participants will perform unilateral leg extension exercise immediately prior to ingestion of the experimental beverage; Dietary supplement: 4 g Whey protein + 1.25 g leucine + 2.6 g Whey peptides
Experimental: Whey + Leucine + Citrulline; After resistance exercise, participants aged 50-79 years will consume 6.6 g Whey protein + 1.25 g Leucine + 0.8 g Citrulline dissolved in 200 mL of water	Behavioral: Resistance Exercise; Participants will perform unilateral leg extension exercise immediately prior to ingestion of the experimental beverage; Dietary supplement: 6.6 g Whey protein + 1.25 g leucine + 0.8 g Citrulline
Sham Comparator: Water; After resistance exercise, participants aged either 20-30 or 50-79 years old will consume 200 mL water	Behavioral: Resistance Exercise; Participants will perform unilateral leg extension exercise immediately prior to ingestion of the experimental beverage; Other: Water control

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The myofibrillar protein synthetic response to protein ingestion	Myofibrillar protein synthesis rates will be assessed during the postabsorptive period for 3 hr and during the 4 hr after the ingestion of the experimental beverages. This will allow us to assess the change from the postabsorptive to the postprandial period	Postabsorptive for 3 hours, Postprandial for 4 hours hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
mTORC1 phosphorylation	Activation of anabolic signaling pathways will be assessed in the fasted state and at 2 and 4 hr after the ingestion of the experimental beverages.	Baseline and at 2 and 4 hours after protein ingestion

Collaborators and Investigators

• Sponsor: University of Illinois at Urbana-Champaign
• Investigators: Principal Investigator: Nicholas A Burd, Ph.D., University of Illinois at Chicago

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2016
• Primary Completion (Actual): March 6, 2019
• Study Completion (Actual): March 6, 2019

Study Registration Dates

• First Submitted: September 20, 2016
• First Submitted That Met QC Criteria: September 27, 2016
• First Posted (Estimate): September 29, 2016

Study Record Updates

• Last Update Posted (Actual): November 3, 2020
• Last Update Submitted That Met QC Criteria: November 2, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 16999

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO