Bed Rest Study SBI 2023

Neuromuscular Decline After Physical Inactivity: a Comparison of Younger and Older Adults

The study will consist of three groups of subjects. Ten young male subjects (18-30 years) will lie supine for 21 days, 10 older male subjects (65+ years) will lie supine for 10 days, and a third group of 10 older male subjects (65+ years) will also lie supine for 10 days but will receive interventions (see below) to counteract the physical changes caused by supine lying. All three groups will be bedridden in the premises of Izola General Hospital. Subjects will be housed in 5-bed rooms at the hospital and will receive 24-hour medical care, proper hygiene, nutrition, passive exercise, Internet, a relaxing environment, and visits. After their stay, subjects return home but receive 21 days of care at local fitness centers. Rehabilitation consists of interval training, in which subjects perform high-intensity exercise for 4 times 5 minutes. A number of important health parameters are measured before, during, and after bed rest. Some of these measurements will be invasive (blood and muscle sampling), for which appropriate medical personnel, sterile instruments, and environment will be available. Measurements will include normal voluntary efforts (indoor cycling, various jumps, short stretches) and electrically evoked muscle contractions (electrical stimulation with single impulses). All tests are normal tests and come from normal lifestyles and routine medical examinations.

Study Overview

• Status: Completed
• Conditions: Healthy Aging; Physical Inactivity
• Intervention / Treatment: Diagnostic test: OGTT; Dietary supplement: High protein diet

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Slovenia
  • Koper, Slovenia, 6000
    • SRC Koper

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• age: for young arm (18-35), for old arm (65-75)
• BMI: 22 in 32 kg/m2
• appendicular muscle mass > 7,23 kg/m2

Exclusion Criteria:

• serious acute or chronic diseases: skeletal, cancer, cardiovascular, metabolic, neuromuscular and psychiatric;
• cardiovascular disease detected on ECG examination;
• allergies to the active substances used in the study;
• problems with digestion of the active substances;
• frequent diarrhea and vomiting;
• arterial hypertension (>140/90 mmHg);
• psychological problems;
• susceptibility to deep vein thrombosis (D-dimer < 500 μg/L)
• poor orthostatic tolerance (frequent dizziness when changing position, especially when rising from a supine position);
• venous abnormalities that would cause difficulty in drawing blood;
• a large blood volume (more than 300 ml) in the last 3 months prior to the start of the project;
• problems with excessive consumption of alcoholic beverages;
• active smoking;
• Previous participation in any biomedical research in the last 3 months prior to the start of this study;
• a communicable disease before the start of the project;
• any ferromagnetic implant.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Old 1; 1. Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.	Diagnostic test: OGTT; Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.
Experimental: Old 2; Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.; Test the ability of high protein diet (1.4 g protein/kg/day) with branched chain amino acid and cysteine supplementation to decrease bed rest induced muscle atrophy, glutathione depletion and insulin resistance in old subjects.	Diagnostic test: OGTT; Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.; Dietary supplement: High protein diet; Test the ability of high protein diet (1.4 g protein/kg/day) with branched chain amino acid and cysteine supplementation to decrease bed rest induced muscle atrophy, glutathione depletion and insulin resistance in old subjects.
Other: Young; 1. Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.	Diagnostic test: OGTT; Assessment of changes in insulin sensitivity (Oral Glucose Tolerance test and muscle insulin signalling: immunofluorescence and western blot of GLUT-4, IRS-1, MPP/TIMP, etc.) following bed rest in old and young subjects.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin sensitivity	Assessment in changes in insulin sensitivity will be made with the use of Oral Glucose Tolerance test (OGTT).	10 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle mass	Muscle mass will be measured with bioimpedance and with DXA.	10 day
Muscle force	Quadriceps femoris maximal voluntary contractions (MVC) in isometric conditions at knee angle set at 30 deg flexion and hip fixed at 90 deg flexion using a custom-made knee dynamometer fitted with a load cell (RS 206-0290).	10 days
Neuromuscular junction stability	We will evaluate the presence of NMJ stability by analysing: AChR subunits expression	10 days

Collaborators and Investigators

• Sponsor: Science and Research Centre Koper
• Collaborators: University of Trieste; University of Udine; University of Padova; Izola General Hospital; University of Pavia; Azienda Sanitaria Universitaria Giuliano Isontina (ASU GI)
• Investigators: Principal Investigator: Rado Pišot, PhD, Science and Research Centre Koper

Study record dates

Study Major Dates

• Study Start (Actual): August 21, 2023
• Primary Completion (Actual): October 22, 2023
• Study Completion (Actual): October 22, 2023

Study Registration Dates

• First Submitted: October 11, 2023
• First Submitted That Met QC Criteria: November 15, 2023
• First Posted (Estimated): November 21, 2023

Study Record Updates

• Last Update Posted (Estimated): November 21, 2023
• Last Update Submitted That Met QC Criteria: November 15, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: BEDREST

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No