Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Class |
|---|---|
| European Space Agency | OTHER |
| University Hospital, Clermont-Ferrand | OTHER |
| Institut Pluridisciplinaire Hubert Curien, Strasbourg, France | UNKNOWN |
The human being has shown that he can live and work in the space environment, but due to the lack of essential mechanical load on muscle and bone, the fluid-shift as well as alterations in the acid-base balance (mainly on account of nutritional factors), the exposure to microgravity results in a gradual degradation of muscle, bone and cartilage, deconditioning of the cardiovascular system and metabolic changes. Countermeasures to prevent all the deconditioning of the physiological systems are not yet fully effective and require further investigation.
A commonly utilized model of simulating the physiological effects of microgravity on the human organism on ground is the 6° head-down-tilt bed rest. In the present study the model has been used to study potential countermeasures to spaceflight-associated deconditioning.
One of the most constrictive changes appearing during space flight as well as during bed rest, are disuse-induced muscle losses. These are associated with a decrease in muscle protein synthesis, rather then an increase in muscle protein breakdown. Besides an effective training countermeasure, nutritional countermeasures gain respect in this context: supplementing conventional diets with whey protein or essential amino acids has been shown to increase muscle protein synthesis. Due to these anabolic properties whey protein seems promising to counteract disuse-induced muscle wasting.
Drawbacks of a high protein intake are calciuric effects, ascribed to the proton-release when metabolizing sulfur-containing amino acids. The so called 'low grade metabolic acidosis' has also shown to activate osteoclastic bone resorption and muscle protein degradation. Therefore, to maximize the anabolic potential of a whey protein supplementation, the acidogenic properties need to be compensated. As previous works suggest, a shift of acid base balance into the acid direction and the resulting changes in bone and protein turnover may be hindered by supplementing alkaline mineral salts.
In this regard, a mid-term bed rest study was performed in order to investigate the effect of a combined whey protein (0.6 g/kg body weight/day) and potassium bicarbonate (90 mmol/day) supplementation as a potential countermeasure to multiple physiological and metabolic alterations on the human body resulting from real and simulated microgravity.
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| MEP-1 | Experimental |
| |
| MEP-2 | Experimental |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Whey Protein + Potassium bicarbonate | Dietary Supplement | 0.6 mmol WP/kg body weight + 90 mmol KHCO3 during bed rest |
|
| Measure | Description | Time Frame |
|---|---|---|
| Change in body composition | Baseline, after 21 days of bed rest |
| Measure | Description | Time Frame |
|---|---|---|
| Plasma Volume | Baseline, after 21 days of bed rest | |
| Maximum volume of oxygen uptake | Baseline, after 21 days of bed rest | |
| Isometric torque |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| DLR German Aerospace Center | Cologne | 51147 | Germany |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 29546280 | Derived | Rudwill F, O'Gorman D, Lefai E, Chery I, Zahariev A, Normand S, Pagano AF, Chopard A, Damiot A, Laurens C, Hodson L, Canet-Soulas E, Heer M, Meuthen PF, Buehlmeier J, Baecker N, Meiller L, Gauquelin-Koch G, Blanc S, Simon C, Bergouignan A. Metabolic Inflexibility Is an Early Marker of Bed-Rest-Induced Glucose Intolerance Even When Fat Mass Is Stable. J Clin Endocrinol Metab. 2018 May 1;103(5):1910-1920. doi: 10.1210/jc.2017-02267. |
Not provided
Not provided
Not provided
| ID | Term |
|---|---|
| D000067816 | Whey Proteins |
| C026329 | potassium bicarbonate |
| ID | Term |
|---|---|
| D008894 | Milk Proteins |
| D000080224 | Animal Proteins, Dietary |
| D004044 | Dietary Proteins |
| D011506 | Proteins |
Not provided
Not provided
| Charite University, Berlin, Germany |
| OTHER |
| University of Milan | OTHER |
| Université de Nice Sophia Antipolis | OTHER |
| University of Ottawa | OTHER |
| Manchester Metropolitan University | OTHER |
| University of Toronto | OTHER |
| Medical University of Graz | OTHER |
| University of Cologne | OTHER |
| Radboud University Medical Center | OTHER |
| University Hospital, Lille | OTHER |
| Leiden University Medical Center | OTHER |
Not provided
Not provided
Not provided
Not provided
Not provided
| Control | Other | Bed rest without dietary supplement |
|
During a an Isometric Maximum Voluntary Contraction Test on the knee extensors & flexors, the plantarflexors and dorsiflexors, the elbow extensors & flexors the Isometric Torque will be measured in Nm. |
| Baseline, after 21 days of bed rest |
| Muscle fatigue | Baseline, after 21 days of bed rest |
| Bone metabolism | Baseline, after 2,5,14,21 days of bed rest, 1, 5, 14, 28 days after finishing bed rest |
| Bone mineral density + content | Baseline, after 21 days of bed rest |
| Standing balance | Baseline, after 21 days of bed rest |
| Locomotion | Locomotion will be assessed by Dynamic Gait Index, specific parameters are: total Score and Subscore | Baseline, after 21 days of bed rest |
| Body mass | Daily for a duration of 35 days |
| Intracranial pressure | Baseline, after 1,4, 7,10,13,14,15,16,17,18,19,20,21 days of bed rest,1,2,4 days after finishing bed rest |
| Monitoring of Vitamin K status | Baseline, after 2,5,14,21 days of bed rest, 1, 5 days after finishing bed rest |
| Fat metabolism | Baseline, after 21 days of bed rest |
| Glucose metabolism | Baseline, after 21 days of bed rest, 4 days after finishing bed rest |
| Nitrogen balance | Daily for a duration of 33 days |
| Energy metabolism | Baseline, after 21 days of bed rest |
| Glucocorticoid activity | Baseline, after 2,3,7,8,12,13,16,17 days of bed rest, 2,3 days after finishing bed rest |
| Muscle metabolism | Baseline, after 21 days of bed rest |
| Acid base balance | Baseline, after 2, 14, 21 days of bed rest, 5 days after finishing bed rest |
| Sympathetic activity during orthostatic stress | Muscle sympathetic nerve activity is measured by MSNA recording by microneurography technique. | Baseline, after 21 days of bed rest |
| Visual Orientation | Visual Orientation is assessed by 'Oriented Character Recognition Test' and Luminous Line Test. The main parameter is Score. | Baseline, after 6,12,20 days of bed rest, 2,4 days after finishing bed rest |
| Plasma galanin and adrenomedullin responses during head up tilt test (orthostatic stress) | Baseline, after 21 days of bed rest |
| Cartilage metabolism and -thickness | Baseline, after 2,3,5,7,14,21 days of bed rest, 5 days after finishing bed rest |
| Hematopoetic system | Blood cell count, reticulocytes, Haptoglobin, Bilirubin, Ferritin, EPO, Thrombopoietin, Urinary Urobilinogen and Fecal Urobilinogen (markers of blood cell degradation) | Baseline, after 10, 21 days of bed rest, 1, 28 days after finishing bed rest |
| Fat accumulation in bone marrow | Baseline, after 10, 21 days of bed rest, 3, 28 days after finishing bed rest |
| Achilles tendon structure | Baseline, after 21 days of bed rest, 2, 28 days after finishing bed rest |
| Headache - frequency and quality | Baseline, daily during 21 days of bed rest |
| Muscle volume | Baseline, after 20, 21 days of bed rest, 3 days after finishing bed rest |
| Free water and fat content in muscle | Baseline, after 20, 21 days of bed rest, 3 days after finishing bed rest |
| Orthostatic tolerance | Orthostatic tolerance will be assessed by Head up tilt test. The following parameters are assessed to measure orthostatic tolerance: beat-to-beat heart rate [bpm], beat-to-beat blood pressure [bpm] time to presyncope [min, s] | Baseline, after 21 days of bed rest |
| D000602 |
| Amino Acids, Peptides, and Proteins |
| D000067796 | Whey |
| D008892 | Milk |
| D003611 | Dairy Products |
| D005502 | Food |
| D000066888 | Diet, Food, and Nutrition |
| D010829 | Physiological Phenomena |
| D019602 | Food and Beverages |