Effect of 14 Day Bed Rest on Health Outcomes in Young and Older Participants
- Conditions
- Muscular Atrophy
- Interventions
- Behavioral: physical inactivity or bed rest with supervised recovery
- Registration Number
- NCT02694471
- Lead Sponsor
- University of Primorska
- Brief Summary
This investigation aimed to compare the response of older adult and young men to 14 day bed-rest and subsequent 28 day rehabilitation. Sixteen older (OM: 55-65 years) and seven young men (YM: 18-30 years) were exposed to 14-day bed rest (BR) followed by 14-day rehabilitation (R), and 400-day of R. Quadriceps muscle volume, force and explosive power of leg extensors, single fiber isometric force, peak aerobic power, gait stride length, and several metabolic were measured before and after BR and after R.
- Detailed Description
Twenty-three healthy men, of which 7 young (YM; aged 18-30 years) and 16 older adults (OM; aged 55-65 years) were recruited for the study. All participants underwent medical examination and routine blood and urine analysis. Exclusion criteria were: smoking; regular alcohol consumption; ferromagnetic implants; history of deep vein thrombosis with D-dimer \> 500 μg·L-1; acute or chronic skeletal, neuromuscular, metabolic and cardiovascular disease conditions; pulmonary embolism. Participants were informed of the purpose, procedures and potential risk of the study before signing the informed consent. The study was performed in accordance with the ethical standards of the 1964 Declaration of Helsinki and was approved by the National Ethical Committee of the Slovenian Ministry of Health on April 17, 2012.
The study was conducted in controlled medical environment of the Orthopedic Hospital of Valdoltra, Slovenia. The participants were housed in standard air conditioned hospital rooms and were under constant surveillance with 24-hour medical care. For 14 days, the participants performed all daily activities in bed and received eucaloric controlled meals three times a day. Dietary energy requirements were designed for each subject multiplying resting energy expenditure by factors 1.2 and 1.4 in BR and ambulatory period, respectively. The resting energy expenditure was calculated as done in previous studies. The macronutrient food content set at 60% of carbohydrates, 25% fat, and 15% of proteins, according to the scheme of the so called "mediterranean diet" and adopted also in previous bed rest protocols. Energy balance was checked weekly by fat mass assessment. The daily protein intake was 1.1-1.25 g kg-1 in both groups, in BR and recovery period respectively, except the subgroups of OM who received a supplementation (see below).
After the BR, participants underwent a rehabilitation protocol (R) that consisted of 4-week supervised multimodal exercise program with 3 sessions per week. In each session, participants performed 12-minute warm-up, 15-20 minutes of balance and strength training, and 20-30 minutes of endurance training.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 23
- Body mass index < 28 kg/m2
- Short physical performance battery score >= 9
- smoking;
- regular alcohol consumption;
- ferromagnetic implants;
- history of deep vein thrombosis with D-dimer > 500 μg·L-1;
- acute or chronic skeletal, neuromuscular, metabolic and cardiovascular disease conditions.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Young group physical inactivity or bed rest with supervised recovery 7 young participants (18-30 years) were included in physical inactivity or bed rest with supervised recovery intervent and underwent 14-day of bed rest. Bed rest was followed by 28-day recovery. During the bed rest participants will remain 24-hour horizontal with all daily activities performed lying in a bed. No social isolation will be forced. During the recovery participants will 3-times weekly per 75 minutes perform guided exercises to achieve baseline level. Old group physical inactivity or bed rest with supervised recovery 16 old participants (55-65 years) were included in physical inactivity or bed rest with supervised recovery intervent and underwent 14-day of bed rest. Bed rest was followed by 28-day recovery. During the bed rest participants will remain 24-hour horizontal with all daily activities performed lying in a bed. No social isolation will be forced. During the recovery participants will 3-times weekly per 75 minutes perform guided exercises to achieve baseline level.
- Primary Outcome Measures
Name Time Method Change in quadriceps muscle volume (young vs. old) after 14-day bed rest At baseline and after 14-day bed rest and on 14th day of recovery Using MRI continous screening of single leg was performed
Change in diameter of single fibre contractions (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery Biopsy samples were obtained from vastus lateralis muscles
Change in peak aerobic power (VO2max) (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery graded cycling on sitting ergometer until exhaustion
- Secondary Outcome Measures
Name Time Method Change in peak knee extensor force (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery Estimated from single leg isometric maximal voluntary contraction
Change in lower limb explosive power (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery estimated from bilateral efforts on explosive ergometer (EXER)
Change in gait stride length (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th and 400th day of recovery Walking through the food placement detection system
Change in insulin sensitivity (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery collected hourly for 6 hours after standard meal load as a measure of insulin sensitivity index
Change in area-under-the curve (AUC) of triglycerides plasma concentration (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery collected hourly for 3 hours after standard meal load
Change in N-telopeptide (young vs. old) after 14-day bed rest baseline, during and after 14-day bed rest and during first 14 day of recovery From urine collection
Change in C-telopeptide (young vs. old) after 14-day bed rest baseline, during and after 14-day bed rest and during first 14 day of recovery From urine collection
Change is contraction time (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery From Tensiomyographic response in vastus lateralis
Change in force of single muscle fibre contraction (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery Biopsy samples were obtained from vastus lateralis muscles
Change in specific force of single muscle fibre contraction (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery Biopsy samples were obtained from vastus lateralis muscles
Change in velocity of single muscle fibre contraction (young vs. old) after 14-day bed rest baseline and after 14-day bed rest and on 14th day of recovery Biopsy samples were obtained from vastus lateralis muscles
Trial Locations
- Locations (1)
Orthopaedic Hospital Valdoltra
🇸🇮Ankaran, Slovenia