BISPHOSPHONATES AS A COUNTERMEASURE TO SPACEFLIGHT-INDUCED
BONE LOSS (BISPHOSPHONATES)
Research Area: Bone and Muscle Physiology
Expeditions: 18- 30
Principal Investigator(s): ● Adrian D. Leblanc, PhD, Universities Space Research
Association, Houston, Texas
● Toshio Matsumoto, PhD, MD, University of Tokushima,
Kuramoto, Japan
RESEARCH OBJECTIVES
The purpose of the Bisphosphonates study is to determine whether an antiresorptive agent, in
conjunction with the routine in-flight exercise program, protects International Space Station
(ISS) crew members from the
regional decreases in bone
mineral density documented on
previous ISS missions.
EARTH BENEFITS
The benefits of this research are
primarily for space travelers.
However, knowledge gained from
this investigation may generate
useful information applicable to
patients on Earth with
accelerated bone loss because of
disuse (eg, spinal cord injury
patients or those with prolonged
immobilization).
SPACE BENEFITS
If shown to be an effective
countermeasure to spaceflight-induced bone loss, bisphosphonates could prevent or reduce
several potential bone-related problems identified in NASA's Critical Path Roadmap. If
bisphosphonates improve the efficiency of in-flight exercise to maintain bone mass, then more
crew time could be made available for other purposes.
RESULTS
Seven ISS astronauts who spent a mean of 5.5 months on the ISS were given an oral dose of
70 mg of alendronate (a bisphosphonate drug used to treat the thinning of bone, ie,
osteoporosis) weekly starting 3 weeks before flight and continuing throughout the mission to
study the effectiveness of alendronate on reducing bone loss. All crew members had a
treadmill, cycle ergometer, and a resistance exercise device available for exercise. Bone
assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA)
Pictured is 1-mm-thick sections through the mid frontal plane of the
hip, showing regions of evaluation in white superimposed on a false
color image of the Quantitative Computed Tomography (QCT) data.
The left-hand image shows the cortical region of the femoral neck,
and the right-hand image shows the trabecular bone regions. NASA
image.