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

This study is ongoing, but not recruiting participants.
Sponsor:
Information provided by (Responsible Party):
Scott M. Smith, National Aeronautics and Space Administration (NASA)
ClinicalTrials.gov Identifier:
NCT01713634
First received: October 19, 2012
Last updated: March 22, 2013
Last verified: March 2013
  Purpose

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 Intervention
Bone Resorption
Other: Preflight
Other: In-flight

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism During Spaceflight and Recovery

Resource links provided by NLM:


Further study details as provided by National Aeronautics and Space Administration (NASA):

Primary Outcome Measures:
  • Change in urinary n-telopeptide after 15 days of space flight compared to preflight [ Time Frame: 15 days ] [ Designated as safety issue: No ]
    24-h NTX will be used as an indicator of bone resorption

  • Change in urinary n-telopeptide after 30 days of space flight compared to preflight [ Time Frame: 30 days ] [ Designated as safety issue: No ]
  • Change in urinary n-telopeptide after 60 days of space flight compared to preflight [ Time Frame: 60 days ] [ Designated as safety issue: No ]
  • Change in urinary n-telopeptide after 120 days of space flight compared to preflight [ Time Frame: 120 days ] [ Designated as safety issue: No ]
  • Change in urinary n-telopeptide after 180 days of space flight compared to preflight [ Time Frame: 180 days ] [ Designated as safety issue: No ]
  • Change in urinary calcium after 15 days of space flight compared to preflight [ Time Frame: 15 days ] [ Designated as safety issue: No ]
  • Change in urinary calcium after 60 days of space flight compared to preflight [ Time Frame: 60 days ] [ Designated as safety issue: No ]
  • Change in urinary calcium after 120 days of space flight compared to preflight [ Time Frame: 120 days ] [ Designated as safety issue: No ]
  • Change in urinary calcium after 180 days of space flight compared to preflight [ Time Frame: 180 days ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Change in urinary calcium after 30 days of space flight compared to preflight [ Time Frame: 30 days ] [ Designated as safety issue: No ]
    24-h urinary calcium


Estimated Enrollment: 16
Study Start Date: January 2009
Estimated Study Completion Date: December 2015
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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)

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

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

Exclusion Criteria:

  • Non-astronauts
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: 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)
  More Information

Additional Information:
Publications:
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
Study First Received: October 19, 2012
Last Updated: March 22, 2013
Health Authority: United States: Federal Government
United States: Institutional Review Board

Keywords provided by National Aeronautics and Space Administration (NASA):
Bone resorption
Diet

Additional relevant MeSH terms:
Bone Resorption
Bone Diseases
Musculoskeletal Diseases

ClinicalTrials.gov processed this record on August 28, 2014