Long-term Effects on Astronaut Bone Health after Space Flight

Biostatistics (Public Health); Biomechanics

This study will collect and analyze the relevant data from the LSAH in order to evaluate the long-term health risks associated with space flight.

Research Interests
  • Data Mining
  • Biomechanics/Injury Biomechanics or Biomechanics and Mechanobiology
Participants
  1. Robert Salzar headshot
    RS
    Robert S. Salzar
    School of Engineering and Applied Science
  2. Kathryn Thornton headshot
    KT
    Kathryn C. Thornton
    School of Engineering and Applied Science
  3. Mark Sochor headshot
    MS
    Mark Sochor
    School of Medicine

GeneralOverview

Measuredareal Bone Mineral Density (aBMD) ofastronauts before and after long-duration spaceflight has shown that prolongedexposure to a microgravity environment can decrease aBMD at a rate of .3% to.5% per month even with the aid of advanced resistive exercise devices (LeBlanc,Schneider, & Schackleford, 2000). These dynamicloads on long-bones can slow the deterioration of BMD (Turner,2000),but little is understood about how cortical and trabecular bone are affected by varying levels of gravity, and thelong-term effects of space flight on astronaut bone health.  NASA keeps detailed health records of allastronauts in the Lifetime Surveilance ofAstronaut Health (LSAH) program, but in-depth analysis of this data interms of the effect of space flight on the human body has not been published.

Ashumanity moves towards more frequent and longer duration space exploration, thelong-term effects of decreasing BMD may put astronauts at higher risk of bonedegeneration and injury as they age. This study will collect and analyze therelevant data from the LSAH in order to evaluate the long-term health risksassociated with space flight and BMD degeneration throughout the lifetime ofthe astronaut. 

Statement of Work         

This project will use lifetime astronautbone and calcium physiology data collected from NASA’s LSAH program to evaluatelong-term bone degeneration risks associated with duration of time in space.  The LSAH collects aBMD every 3 years on each active and retired astronaut.  This data will allow us to precisely relatemeasures of bone health to time spent in space; we will use this to explorewhether space-flight associated decreases in aBMD are permanent and whether astronauts exhibit long-term differences frommatched non-astronaut controls (similar non-astronauts also followed for life as part of the LSAH program).  This analysis will be performed usingstatistical “mixed” models, which correctly account for repeated measurementson individuals, and will account for the known differences in bone aging bysex.   A total of $60,000 across the team is beingrequested to fund the time and effort put forth by the principals and theassigned graduate student.

Desired outcomes

Determineany life-long risks to bone health in astronauts as it relates to time spent inspace.  Access to LSAH data will be aidedby Dr. Kathy Thornton, with medical significance assessed by Dr. MarkSochor.  Dr. Rob Salzar and Dr.Tim McMurry will direct and advise the appointed graduate students assignedto perform the statistical analysis. Significant findings will be published and used to direct additionalresearch directions required for long-term space exposures.