Toulouse Male Long Term Bed Rest 2001-2002
Microgravity during space flight induces physiological changes that affect astronauts’ health and performance. Space flight simulations such as prolonged bed rest can mimic some of these changes and provide study conditions that are more accessible than during space flight. The European Space Agency, ESA together with the French national space agency, CNES and the Japanese national space agency, NASDA are performing extensive studies using long duration bed rest.
Previous studies including several long and short term bed rest campaigns have yielded significant medical data on the physiological changes induced by space flight. These data can be used to study the effect of countermeasures, methods helping to prevent these physiological changes.
The long duration bed rest, lasting 3 months undertakes a variety of investigations involving 28 subjects. This study focuses on countermeasures, studying the effect of a bone tissue stabilisation medication and resistive exercises to determine their suitability for use during long duration stays on ISS.
The physiological changes recorded during space flight and bed rest mimic those observed in some diseases and in the aging process. Significant clinical applications are expected as a direct result of this experiment and future equivalent studies.
Simulation of Weightlessness by Anti-Orthostatic Long Term Bed Rest
Behavioral: Physical training
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
|Official Title:||Simulation of a Mission Aboard the International Space Station by a Long Duration Anti-Orthostatic Bed Confinement at – 6° (90 Days) on Healthy Subjects:1/Perfecting of Preventive Methods (Muscular Exercise and Biphosphonates) and Evaluation of the Effects on the Locomotion and Cardiovascular Systems and on the Lipid and Energy Metabolisms. 2/Pharmacokinetic Assessment: Effects of Position on the Absorption Mechanisms: Pharmacokinetics of Paracetamol Used as Model to Study Oral Absorption in Simulated Weightlessness|
- Muscle size and function
- Muscle protein composition, muscle fiber type composition andmuscle enzyme content of soleus and vastus lateralis muscles
- Bone mineral content and structure
- Isokinetic muscle strength (using Cybex)
- Fluid volume shift
- Calcium metabolism and hormonal control
- Sleep assessment by questionnaires and actigraphy
- RR interval from an ECG lead signal by an high impedance probe, Systolic (SAP), Diastolic (DAP) and Mean arterial pressure (MAP) by Finapres (or Portapres) andRespiration by a piezoelectric pneumobelt,
- Acetaminophen pharmacokinetic parameters,
- 24 h profile of spine geometry,flexibility index of spine, activity of lower back muscles,
- and subjective rating of back pain
- Maximal oxygen consumption.
- Cardiovascular oxygen transport (oxygen delivery and oxygen return), requiring measurement of cardiac output, heart rate, arterialized blood gas composition, and arterial oxygen saturation.
- Gas exchange kinetics at the onset and offset of exercise, requiring measurement of breath-by-breath ventilation and expired gas composition.
- Blood volume
- Plasma concentrations of arginin vasopressin, atrial natriuretic peptide, renin, endothelin, cyclic GMP and catecholamines. Urine concentrations of catecholamines, arginin vasopressin and cyclic GMP Blood concentration of nitric oxide.
- Total energy expenditure, Lipid metabolism, body composition, water turnover and the formation of metabolic water.
- Heart rate variability and post-ganglionic sympathetic nerve activity.
- Arterial cardiac chronotropic baroreflex sensitivity and ventricular interdependence.
- Ventricular mass and cardiac dimension.
- Muscle architecture, including angle of pennation, fibre length, muscle thickness and muscle cross-sectional area
- Energetics and biomechanics of walking and running
- Parameters of vascular peripheral hemodynamics
- Parameters of central hemodynamics
|Study Start Date:||August 2001|
|Estimated Study Completion Date:||June 2003|
Please refer to this study by its ClinicalTrials.gov identifier: NCT00311571
|Toulouse, France, 31405|
|Principal Investigator:||Jacques Bernard, Dr||MEDES-IMPS|