Dietary Intake Modifications to Protect Against Changes in Bone Metabolism (ProK)
Primary Purpose
Bone Resorption
Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Preflight
In-flight
Sponsored by
About this trial
This is an interventional prevention trial for Bone Resorption focused on measuring Bone resorption, Diet
Eligibility Criteria
Inclusion Criteria:
- Astronauts flying on long-duration (3-6 months) spaceflights
Exclusion Criteria:
- Non-astronauts
Sites / Locations
- Johnson Space Center
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Experimental
Arm Label
Low Apro/K Diet
High Apro/K Diet
Arm Description
Subjects consume a prescribed diet for 4 days with a low ratio of animal protein to potassium (0.3-0.6 g/mEq).
Subjects consume a prescribed diet that has a high ratio of animal protein to potassium (1.0-1.3 g/mEq) for 4 days.
Outcomes
Primary Outcome Measures
Change in urinary n-telopeptide after 15 days of space flight compared to preflight
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
Change in urinary n-telopeptide after 60 days of space flight compared to preflight
Change in urinary n-telopeptide after 120 days of space flight compared to preflight
Change in urinary n-telopeptide after 180 days of space flight compared to preflight
Change in urinary calcium after 15 days of space flight compared to preflight
Change in urinary calcium after 60 days of space flight compared to preflight
Change in urinary calcium after 120 days of space flight compared to preflight
Change in urinary calcium after 180 days of space flight compared to preflight
Secondary Outcome Measures
Change in urinary calcium after 30 days of space flight compared to preflight
24-h urinary calcium
Full Information
NCT ID
NCT01713634
First Posted
October 19, 2012
Last Updated
November 13, 2015
Sponsor
National Aeronautics and Space Administration (NASA)
1. Study Identification
Unique Protocol Identification Number
NCT01713634
Brief Title
Dietary Intake Modifications to Protect Against Changes in Bone Metabolism
Acronym
ProK
Official Title
Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism During Spaceflight and Recovery
Study Type
Interventional
2. Study Status
Record Verification Date
November 2015
Overall Recruitment Status
Completed
Study Start Date
January 2009 (undefined)
Primary Completion Date
November 2015 (Actual)
Study Completion Date
November 2015 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
National Aeronautics and Space Administration (NASA)
4. Oversight
Data Monitoring Committee
No
5. Study Description
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.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Bone Resorption
Keywords
Bone resorption, Diet
7. Study Design
Primary Purpose
Prevention
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
17 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Low Apro/K Diet
Arm Type
Experimental
Arm Description
Subjects consume a prescribed diet for 4 days with a low ratio of animal protein to potassium (0.3-0.6 g/mEq).
Arm Title
High Apro/K Diet
Arm Type
Experimental
Arm Description
Subjects consume a prescribed diet that has a high ratio of animal protein to potassium (1.0-1.3 g/mEq) for 4 days.
Intervention Type
Other
Intervention Name(s)
Preflight
Intervention Description
4-d controlled diet sessions will occur twice before flight.
Intervention Type
Other
Intervention Name(s)
In-flight
Intervention Description
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 Measure Information:
Title
Change in urinary n-telopeptide after 15 days of space flight compared to preflight
Description
24-h NTX will be used as an indicator of bone resorption
Time Frame
15 days
Title
Change in urinary n-telopeptide after 30 days of space flight compared to preflight
Time Frame
30 days
Title
Change in urinary n-telopeptide after 60 days of space flight compared to preflight
Time Frame
60 days
Title
Change in urinary n-telopeptide after 120 days of space flight compared to preflight
Time Frame
120 days
Title
Change in urinary n-telopeptide after 180 days of space flight compared to preflight
Time Frame
180 days
Title
Change in urinary calcium after 15 days of space flight compared to preflight
Time Frame
15 days
Title
Change in urinary calcium after 60 days of space flight compared to preflight
Time Frame
60 days
Title
Change in urinary calcium after 120 days of space flight compared to preflight
Time Frame
120 days
Title
Change in urinary calcium after 180 days of space flight compared to preflight
Time Frame
180 days
Secondary Outcome Measure Information:
Title
Change in urinary calcium after 30 days of space flight compared to preflight
Description
24-h urinary calcium
Time Frame
30 days
10. Eligibility
Sex
All
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
Astronauts flying on long-duration (3-6 months) spaceflights
Exclusion Criteria:
Non-astronauts
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Scott M Smith, PhD
Organizational Affiliation
National Aeronautics and Space Administration (NASA)
Official's Role
Principal Investigator
Facility Information:
Facility Name
Johnson Space Center
City
Houston
State/Province
Texas
ZIP/Postal Code
77058
Country
United States
12. IPD Sharing Statement
Citations:
PubMed Identifier
15447920
Citation
Zwart SR, Hargens AR, Smith SM. The ratio of animal protein intake to potassium intake is a predictor of bone resorption in space flight analogues and in ambulatory subjects. Am J Clin Nutr. 2004 Oct;80(4):1058-65. doi: 10.1093/ajcn/80.4.1058.
Results Reference
background
PubMed Identifier
15691900
Citation
Zwart SR, Davis-Street JE, Paddon-Jones D, Ferrando AA, Wolfe RR, Smith SM. Amino acid supplementation alters bone metabolism during simulated weightlessness. J Appl Physiol (1985). 2005 Jul;99(1):134-40. doi: 10.1152/japplphysiol.01406.2004. Epub 2005 Feb 3. Erratum In: J Appl Physiol (1985). 2013 Sep;115(6):950.
Results Reference
background
PubMed Identifier
29722847
Citation
Zwart SR, Rice BL, Dlouhy H, Shackelford LC, Heer M, Koslovsky MD, Smith SM. Dietary acid load and bone turnover during long-duration spaceflight and bed rest. Am J Clin Nutr. 2018 May 1;107(5):834-844. doi: 10.1093/ajcn/nqy029.
Results Reference
derived
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Dietary Intake Modifications to Protect Against Changes in Bone Metabolism
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