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Dietary Intake Modifications to Protect Against Changes in Bone Metabolism (ProK)

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ClinicalTrials.gov Identifier: NCT01713634
Recruitment Status : Completed
First Posted : October 25, 2012
Last Update Posted : November 16, 2015
Sponsor:
Information provided by (Responsible Party):
Scott M. Smith, National Aeronautics and Space Administration (NASA)

Brief Summary:
Bone loss is not only a well-documented effect of spaceflight on astronauts, but also a condition that affects millions of men and women on Earth each year. Many countermeasures to bone loss have been proposed, and many have been evaluated to some degree. To date, those showing potential have focused on either exercise or pharmacological interventions, but none have targeted dietary intake alone as a factor to predict or minimize bone loss during spaceflight. The investigators proposed to document how the ratio of acid precursors to base precursors in the diet is related to directional changes in markers of bone resorption and formation during flight and recovery from flight. There is a high likelihood for success in predicting the extent of bone loss from dietary intake patterns of astronauts during spaceflight, given that this concept is strongly anchored in data obtained from ground-based experiments in our laboratory and others. The notion of manipulating diet to minimize bone loss could also have significant social and economic impacts for NASA and for the general public - especially given the increasing trends for diets that are high in animal protein and low in fruits and vegetables. The results of the proposed experiments will lead to development of a dietary countermeasure for bone loss consisting of a balanced diet with no associated risks for side effects that might be present with pharmaceuticals or supplements, no requirement for payload mass, and no additional crew time necessary during flight.

Condition or disease Intervention/treatment Phase
Bone Resorption Other: Preflight Other: In-flight Not Applicable

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 17 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism During Spaceflight and Recovery
Study Start Date : January 2009
Actual Primary Completion Date : November 2015
Actual Study Completion Date : November 2015

Arm Intervention/treatment
Experimental: Low Apro/K Diet
Subjects consume a prescribed diet for 4 days with a low ratio of animal protein to potassium (0.3-0.6 g/mEq).
Other: Preflight
4-d controlled diet sessions will occur twice before flight.
Other: In-flight
4-d controlled diet sessions will take place on flight days 15, 60, 120, and 180. Flight day 30 will only be monitored intakes (subject consume nominal intake)
Experimental: High Apro/K Diet
Subjects consume a prescribed diet that has a high ratio of animal protein to potassium (1.0-1.3 g/mEq) for 4 days.
Other: Preflight
4-d controlled diet sessions will occur twice before flight.
Other: In-flight
4-d controlled diet sessions will take place on flight days 15, 60, 120, and 180. Flight day 30 will only be monitored intakes (subject consume nominal intake)



Primary Outcome Measures :
  1. Change in urinary n-telopeptide after 15 days of space flight compared to preflight [ Time Frame: 15 days ]
    24-h NTX will be used as an indicator of bone resorption

  2. Change in urinary n-telopeptide after 30 days of space flight compared to preflight [ Time Frame: 30 days ]
  3. Change in urinary n-telopeptide after 60 days of space flight compared to preflight [ Time Frame: 60 days ]
  4. Change in urinary n-telopeptide after 120 days of space flight compared to preflight [ Time Frame: 120 days ]
  5. Change in urinary n-telopeptide after 180 days of space flight compared to preflight [ Time Frame: 180 days ]
  6. Change in urinary calcium after 15 days of space flight compared to preflight [ Time Frame: 15 days ]
  7. Change in urinary calcium after 60 days of space flight compared to preflight [ Time Frame: 60 days ]
  8. Change in urinary calcium after 120 days of space flight compared to preflight [ Time Frame: 120 days ]
  9. Change in urinary calcium after 180 days of space flight compared to preflight [ Time Frame: 180 days ]

Secondary Outcome Measures :
  1. Change in urinary calcium after 30 days of space flight compared to preflight [ Time Frame: 30 days ]
    24-h urinary calcium



Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Astronauts flying on long-duration (3-6 months) spaceflights

Exclusion Criteria:

  • Non-astronauts

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 ClinicalTrials.gov identifier (NCT number): NCT01713634


Locations
United States, Texas
Johnson Space Center
Houston, Texas, United States, 77058
Sponsors and Collaborators
National Aeronautics and Space Administration (NASA)
Investigators
Principal Investigator: Scott M Smith, PhD National Aeronautics and Space Administration (NASA)

Additional Information:
Publications:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Scott M. Smith, Manager for Nutritional Biochemistry, National Aeronautics and Space Administration (NASA)
ClinicalTrials.gov Identifier: NCT01713634     History of Changes
Other Study ID Numbers: Pro0225
First Posted: October 25, 2012    Key Record Dates
Last Update Posted: November 16, 2015
Last Verified: November 2015

Keywords provided by Scott M. Smith, National Aeronautics and Space Administration (NASA):
Bone resorption
Diet

Additional relevant MeSH terms:
Bone Resorption
Bone Diseases
Musculoskeletal Diseases