The Effects of Varying Protein Intakes on Muscle Protein Synthesis During Injury-Mediated Muscle Disuse

Status: Recruiting
Location: See location...
Intervention Type: Dietary supplement
Study Type: Interventional
Study Phase: Not Applicable
SUMMARY

Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Loss of muscle under these conditions is attributed to a persistent negative net muscle protein balance (muscle protein synthesis \[MPS\] \< muscle protein breakdown) that results, in part, from declines in postprandial MPS (i.e., anabolic resistance). Nutritional interventions that enhance postprandial MPS may be used to overcome disuse-induced anabolic resistance and preserve muscle mass to accelerate recovery and improve recovery outcomes. While supplemental protein has been explored as a potential countermeasure to disuse-induce anabolic resistance, the observed efficacy of such interventions has been mixed. Equivocal findings across studies may be attributed, in part, to an insufficient understanding of what constitutes an effective protein-based intervention. Importantly, no study to date has determined an optimal protein dose for overcoming disuse-induce anabolic resistance, or if there is a threshold for maximally stimulating postprandial MPS under disuse conditions. Therefore, the objective of this work is to determine rates of MPS at rest and in response to standard (20 g) or high (40 g) doses of whey protein during knee immobilization (DISUSE) compared with standard activity (ACTIVE)

Eligibility
Participation Requirements
Sex: All
Minimum Age: 17
Maximum Age: 39
Healthy Volunteers: t
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• Men and women aged 18-39 years (17-39 years if military personnel)

• Body mass index (BMI) between 18.5-32 kg/m2

• Routinely participate in aerobic and/or resistance exercise at least 2 days per week.

• Willing to refrain from alcohol, smoking, smokeless nicotine products (includes e-cigarettes, vaping, chewing tobacco), and dietary supplements (i.e., vitamin D, probiotics) 24 hours before and during immobilization and final testing day.

• Willing to only consume caffeine products provided by study staff during the study.

• Supervisor approval for federal civilian employees and non-SRV active-duty military personnel stationed at NSSC.

• Biological females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or on continuous hormonal contraception (i.e., IUD or oral contraceptives without placebo).

Locations
United States
Massachusetts
US Army Research Institute of Environmental Medicine
RECRUITING
Natick
Contact Information
Primary
Emily E Howard, PhD
emily.e.howard14.civ@health.mli
508-206-2309
Time Frame
Start Date: 2025-09-01
Estimated Completion Date: 2026-09
Participants
Target number of participants: 28
Treatments
Active_comparator: Standard Protein Dose
Participants will consume 20 g of whey protein after 5 days of muscle disuse
Active_comparator: High Protein Dose
Participants will consume 40 g of whey protein after 5 days of muscle disuse
Related Therapeutic Areas
Sponsors
Leads: United States Army Research Institute of Environmental Medicine

This content was sourced from clinicaltrials.gov