Medium-term Bedrest Whey Protein (MEP)

This study has been completed.
Sponsor:
Collaborators:
European Space Agency
University Hospital, Clermont-Ferrand
Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
Charite University, Berlin, Germany
University of Milan
University of Nice, France
University of Ottawa
Manchester Metropolitan University
University of Toronto
Medical University of Graz
University of Cologne
Radboud University
University Hospital, Lille
Leiden University Medical Center
Information provided by (Responsible Party):
DLR German Aerospace Center
ClinicalTrials.gov Identifier:
NCT01655979
First received: July 23, 2012
Last updated: July 31, 2012
Last verified: July 2012
  Purpose

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.


Condition Intervention
Countermeasure Evaluation
Dietary Supplement: Whey Protein + Potassium bicarbonate
Other: Control

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment

Resource links provided by NLM:


Further study details as provided by DLR German Aerospace Center:

Primary Outcome Measures:
  • Change in body composition [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Plasma Volume [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Maximum volume of oxygen uptake [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Isometric torque [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
    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.

  • Muscle fatigue [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Bone metabolism [ Time Frame: Baseline, after 2,5,14,21 days of bed rest, 1, 5, 14, 28 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Bone mineral density + content [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Standing balance [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Locomotion [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
    Locomotion will be assessed by Dynamic Gait Index, specific parameters are: total Score and Subscore

  • Body mass [ Time Frame: Daily for a duration of 35 days ] [ Designated as safety issue: No ]
  • Intracranial pressure [ Time Frame: 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 ] [ Designated as safety issue: No ]
  • Monitoring of Vitamin K status [ Time Frame: Baseline, after 2,5,14,21 days of bed rest, 1, 5 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Fat metabolism [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Glucose metabolism [ Time Frame: Baseline, after 21 days of bed rest, 4 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Nitrogen balance [ Time Frame: Daily for a duration of 33 days ] [ Designated as safety issue: No ]
  • Energy metabolism [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Glucocorticoid activity [ Time Frame: Baseline, after 2,3,7,8,12,13,16,17 days of bed rest, 2,3 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Muscle metabolism [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Acid base balance [ Time Frame: Baseline, after 2, 14, 21 days of bed rest, 5 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Sympathetic activity during orthostatic stress [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
    Muscle sympathetic nerve activity is measured by MSNA recording by microneurography technique.

  • Visual Orientation [ Time Frame: Baseline, after 6,12,20 days of bed rest, 2,4 days after finishing bed rest ] [ Designated as safety issue: No ]
    Visual Orientation is assessed by 'Oriented Character Recognition Test' and Luminous Line Test. The main parameter is Score.

  • Plasma galanin and adrenomedullin responses during head up tilt test (orthostatic stress) [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
  • Cartilage metabolism and -thickness [ Time Frame: Baseline, after 2,3,5,7,14,21 days of bed rest, 5 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Hematopoetic system [ Time Frame: Baseline, after 10, 21 days of bed rest, 1, 28 days after finishing bed rest ] [ Designated as safety issue: No ]
    Blood cell count, reticulocytes, Haptoglobin, Bilirubin, Ferritin, EPO, Thrombopoietin, Urinary Urobilinogen and Fecal Urobilinogen (markers of blood cell degradation)

  • Fat accumulation in bone marrow [ Time Frame: Baseline, after 10, 21 days of bed rest, 3, 28 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Achilles tendon structure [ Time Frame: Baseline, after 21 days of bed rest, 2, 28 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Headache - frequency and quality [ Time Frame: Baseline, daily during 21 days of bed rest ] [ Designated as safety issue: No ]
  • Muscle volume [ Time Frame: Baseline, after 20, 21 days of bed rest, 3 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Free water and fat content in muscle [ Time Frame: Baseline, after 20, 21 days of bed rest, 3 days after finishing bed rest ] [ Designated as safety issue: No ]
  • Orthostatic tolerance [ Time Frame: Baseline, after 21 days of bed rest ] [ Designated as safety issue: No ]
    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]


Enrollment: 10
Study Start Date: August 2011
Primary Completion Date: April 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: MEP-1 Dietary Supplement: Whey Protein + Potassium bicarbonate
0.6 mmol WP/kg body weight + 90 mmol KHCO3 during bed rest
Other: Control
Bed rest without dietary supplement
Experimental: MEP-2 Dietary Supplement: Whey Protein + Potassium bicarbonate
0.6 mmol WP/kg body weight + 90 mmol KHCO3 during bed rest
Other: Control
Bed rest without dietary supplement

  Eligibility

Ages Eligible for Study:   20 Years to 45 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy males, 20 -45 years
  • BMI: 20 - 25 kg/m2
  • Height: 158 - 190 cm
  • Weight: 65 - 85 kg
  • maximum relative oxygen uptake: 30 - 60 ml/min/kg
  • non-smokers
  • successful medical and psychological screening
  • Willingness to participate in the entire study
  • signed informed consent
  • social insurance
  • Clear criminal background check

Exclusion Criteria:

  • Abuse of drugs, medicine or alcohol
  • Vegetarians, Vegans
  • Migraines
  • History of mental illness
  • Claustrophobia
  • History of: thyroid dysfunction, renal stones, diabetes, allergies, hypertension, hypocalcaemia, uric acidaemia, lipidaemia, hyperhomocysteinaemia
  • Rheumatism
  • Muscle-, Cartilage- or Joint Injuries
  • Gastro-esophageal reflux disease, renal function disorder, Hiatus hernia
  • Chronic back pain
  • Bone diseases
  • Herniated discs
  • Achilles tendon injuries
  • Cruciate ligament rupture or any other severe knee injury
  • BMD more than 1.5 SD < t-score
  • History of orthostatic intolerance or vestibular disorders
  • Anaemia
  • Vitamin D Deficiency
  • Positive response in thrombosis screening
  • Use of metallic implants, osteosynthesis material
  • Porphyria, Blood dyscrasia
  • HIV, Hepatitis
  • Increased Inner Eye pressure
  • Intolerance to local anesthetics
  • Participation in another study up to three month before study onset
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01655979

Locations
Germany
DLR German Aerospace Center
Cologne, Germany, 51147
Sponsors and Collaborators
DLR German Aerospace Center
European Space Agency
University Hospital, Clermont-Ferrand
Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
Charite University, Berlin, Germany
University of Milan
University of Nice, France
University of Ottawa
Manchester Metropolitan University
University of Toronto
Medical University of Graz
University of Cologne
Radboud University
University Hospital, Lille
Leiden University Medical Center
  More Information

No publications provided

Responsible Party: DLR German Aerospace Center
ClinicalTrials.gov Identifier: NCT01655979     History of Changes
Other Study ID Numbers: ESA-AO-06-BR
Study First Received: July 23, 2012
Last Updated: July 31, 2012
Health Authority: Germany: Ethics Commission

ClinicalTrials.gov processed this record on April 16, 2014