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Short Term Bed Rest Study: Evaluation of the Use of Artificial Gravity, Induced by Short-arm Centrifugation (SAG)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01820702
Recruitment Status : Completed
First Posted : March 29, 2013
Last Update Posted : March 29, 2013
European Space Agency
University Hospital, Angers
Politecnico di Milano
University Hospital, Bonn
University of Zurich
Leiden University Medical Center
German Sport University, Cologne
Information provided by (Responsible Party):
DLR German Aerospace Center

Brief Summary:
Randomized cross-over design with 10 male subjects and 3 campaigns to test whether the negative effects of bed rest (6º head-down tilt) on the various systems of the body and the consequences to health of simulated weightlessness can be counteracted by the use of a defined training programme.

Condition or disease Intervention/treatment Phase
Bone Diseases, Metabolic Acid-Base Imbalance Muscular Atrophy Sprains and Strains Protein Metabolism Body Weight Changes Cardiovascular Abnormalities Other: Defined Training Programme Not Applicable

Detailed Description:

The SAG study was a single center, open-label crossover trial with healthy men conducted in three campaigns at the Institute of Aerospace Medicine, Cologne, Germany.

The subjects were quasi randomized alternatively by enrolment to undertake the different training interventions or to be in the control group during 5 days of immobilisation in 6° head down tilt position. The subjects were quasi randomized either to the one of the training programs or the non-training group depending on the arrival at the Institute of Aerospace Medicine.

The study started November 01st, 2010 and was finished May 29th, 2011. The first campaign lasted from November 01st to November 21sh, 2010, the second campaign from January 10th to January 30th, 2011 and the third campaign from May 09th to May 29th, 2011.

Each campaign comprised a 5 day adaptation-, a 5 day intervention phase in HDT bed rest, and a 5 day recovery phase (15 days in total) in-house at the Metabolic Ward of the Institute of Aerospace Medicine.

Baseline Data were collected during the adaptation phase (BDC Baseline Data Collection) when subjects could move free inside the lab. The intervention was administered during the bed rest phase where the subjects had to lie in bed in 6° head down tilt (HDT Head Down Tilt) position and were not allowed to get up. Recumbency was to be adhered to at all times including all activities (hygienic procedures, leisure activities). The bed rest phase was followed by a recovery phase (R+).

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 10 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Short Term Bed Rest Study: Evaluation of the Use of Artificial Gravity, Induced by Short-arm Centrifugation or the Appliance of Definite Combined Training Program to Counteract Effects of Bed Rest (Acronym: SAG Study)
Study Start Date : November 2010
Actual Primary Completion Date : May 2011
Actual Study Completion Date : May 2011

Arm Intervention/treatment
Active Comparator: defined training programme Other: Defined Training Programme
A Smith Machine with fixed rails was used to guide the heel raise and squat exercises in the vertical axis. A metronome was used to direct the subjects during the performance of the exercises. Squats and heel raises were performed against body weight plus the additional weight of the barbell (15 kg). The heel raises were performed with straight knees and without ankle dorsiflexion. The shallow squats were performed continuously for 3 minutes. The hopping and the cross-hopping exercises were performed without Smith Machine. The bilateral hops were performed at ~ 3 repetitions per second with 15-s rest insertions between each set. Cross-hopping was performed continuously for 3 minutes against ~ 1.3 repetitions per second. Except for the duration of the static squat, with progressed from 45 s at HDT1 to 70 s at HDT5, none of the exercises were progressed during the study. Including the scheduled rest pauses, the LRT sessions were completed in 24 minutes.

No Intervention: Control

Primary Outcome Measures :
  1. Maximal knee extensor and plantar flexor muscle force [ Time Frame: Baseline, after 5 days of bed rest ]
    The maximal voluntary isometric force (MVC) was assessed before and following bed rest. MVC measurements were obtained from the left leg using the Biodex 3 system (Biodex Medical Systems, Shirley, New York, USA).

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • • Healthy male test subjects, aged between 20 and 45 years old with a Body Mass Index (BMI) of 20 - 26 kg/m2 and a height of 158 - 190 cm (62 - 75 inches)

    • 65 - 85 kg
    • Not a competitive athlete
    • Non-smoker, for at least six months before the start of the study
    • In the position to participate in the complete study
    • Demonstrable social insurance and official certificate of absence of criminal record
    • Successful completion of screening examination
    • Provision of Declaration on Consent at the start of the study

Exclusion Criteria:

  • • Drug, medication or alcohol abuse (regular consumption of more than 20-30 g alcohol/day)

    • Smoking
    • Vegetarian, vegan
    • Migraine
    • Previous psychiatric illness
    • Claustrophobia
    • Hiatus hernia
    • Gastro-oesophageal reflux
    • Diabetes mellitus
    • Rheumatic illness
    • Muscle or joint disorder
    • Prolapse of intervertebral disk
    • Pronounced orthostatic intolerance
    • Hyperlipidaemia (deviations from standard values, standard values: TG < 180 mg/dl, cumulative CH < 200 mg/dl, HDL > 35 mg/dl, LDL < 160 mg/dl)
    • Renal dysfunction (deviation from plasma creatinin standard values, standard value < 1.20 mg/dl)
    • Thyroid dysfunction (deviation from standard values for plasma TSH, standard value TSH 0.27 - 4.20 U/l)
    • Hyperhomocysteinemia (deviation from standard value for plasma homocysteine, standard value homocysteine >15 µmol/l)
    • Hyper-, Hypouricemia (deviation from plasma uric acid standard values, age dependent standard value 3.0-6.9 mg/dl)
    • Hyper-, Hypocalcemia (deviation from plasma calcium standard values, age dependent standard value 2.15-2.64 mmol/l)
    • Anaemia: (< as standard values for plasma haemoglobin, standard values for men 13.5-17.5 g/dl)
    • Iron deficiency: ferritin < 30 µg/l
    • Vitamin D deficiency: D3-25-OH < 50 ng/ml
    • Blood gas values deviating from the normal values:

      • pH 7.38-7.42
      • pCO2 34-45 mmHg
      • pO2 79-98 mmHg
      • HCO3 20-28 mmol/l
      • Base deviation ± 2 mmol/l
    • Family history of thrombosis or positive response in thrombosis screening procedure: Biochemical analysis of the following parameter: ATIII, protein C and S activities, factor V Leiden, prothrombin mutants, lupus PTT
    • Chronic back complaints
    • Bone fracture in the year preceding the study
    • Bone density of the femur and lower spine (L1-L4) 1.5 SD ≤ t-score
    • Metal implants or other kinds of bone synthesis materials
    • Participation in another clinical study within the last 2 months before start of this study
    • Imprisoned at the time of the study
    • Any other condition which makes the test subject unsuitable for study inclusion in the opinion of the examiner

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01820702

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German Aerospace Center (DLR)
Cologne, Germany, 51147
Sponsors and Collaborators
DLR German Aerospace Center
European Space Agency
University Hospital, Angers
Politecnico di Milano
University Hospital, Bonn
University of Zurich
Leiden University Medical Center
German Sport University, Cologne
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Study Director: Edwin Mulder, Dr. German Aerospace Center

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Responsible Party: DLR German Aerospace Center Identifier: NCT01820702    
Other Study ID Numbers: Contract 22126/08/NL/VJ (SAG)
First Posted: March 29, 2013    Key Record Dates
Last Update Posted: March 29, 2013
Last Verified: March 2013
Keywords provided by DLR German Aerospace Center:
bone metabolism
acid base balance
bed rest
Additional relevant MeSH terms:
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Sprains and Strains
Bone Diseases
Bone Diseases, Metabolic
Muscular Atrophy
Cardiovascular Abnormalities
Metabolic Diseases
Acid-Base Imbalance
Body Weight
Body Weight Changes
Pathological Conditions, Anatomical
Congenital Abnormalities
Signs and Symptoms
Wounds and Injuries
Neuromuscular Manifestations
Neurologic Manifestations
Nervous System Diseases
Musculoskeletal Diseases
Cardiovascular Diseases