STONY BROOK, N.Y., March 3, 2004—Two studies using a novel non-invasive, non-pharmacologic intervention for the prevention of osteoporosis showed a significant improvement for post-menopausal women and children with cerebral palsy, where bone fragility is of particular concern. The studies, which appear in the March issue of the Journal of Bone and Mineral Research, were led by Clinton Rubin, Ph.D., Professor and Director of the Center for Biotechnology and Chair of the Department of Biomedical Engineering at Stony Brook University, and a national expert on osteoporosis.
The intervention is based on “loading” the skeleton of the standing subject with extremely small vibrations, mimicking what active muscles do when the body is taking short, quick steps. Twenty million people in our country alone suffer from osteoporosis. Further, the disease is considered one of the greatest obstacles to extended human presence in space.
The Stony Brook research also may have consequences for the planned manned Mission to Mars. Loss of bone density and strength is compounded in extended space flight and Dr. Rubin and two Stony Brook colleagues, Drs. Stefan Judex and Yi-Xian Qin, have received an multi-year award from NASA to develop a “prospective flight experiment” that is currently in the design and development stage at Stony Brook. The goal of this project will be to adapt the vibration platform for use by astronauts in the International Space Station as a countermeasure for microgravity induced osteoporosis. Perhaps, in this way, the skeleton can be “tricked” into thinking it is still subject to earth’s gravitational loading.
In describing the work, Dr. Rubin said: “Bone is extremely sensitive to small changes in its mechanical environment. Long term bed-rest, or extended space flight, causes the skeleton to erode away. The converse is also true… increases in mechanical loading can stimulate the skeleton to increase its density… just like the professional tennis player that has 35% more bone on the playing arm than the arm that simply throws the ball into the air. The challenge for biomedical scientists is to determine what it is about mechanical loading that is so critical to the skeleton.”
Dr. Rubin’s research focuses on the use of low-magnitude, high-frequency mechanical vibrations, which is administered to patients non-invasively using a small bathroom-scale like object that “shakes” at 30 cycles per second, similar to the frequency that muscle is active at. First tested in mice, rats and sheep, it was shown that exposure to mechanical signals would increase bone mass and improve bone strength. This approach was next tested on post-menopausal women. Here, a one-year prospective, randomized, double blind, and placebo-controlled clinical trial in 70 women, three to eight years past the menopause, examined the ability of high frequency, low magnitude mechanical signals to inhibit bone loss in the human.
The results from this study, done in collaboration with Dr. Robert Recker at Creighton University, indicate that short daily exposure to these signals can effectively inhibit the bone loss which normally follows the menopause, perhaps most effectively in the spine of lighter women who are in the greatest need of intervention. Post-menopausal women can lose two per cent of their bone density a year; astronauts can lose two percent of their bone density per month.
The study involving children with cerebral palsy, explored the potential of short durations of low-level mechanical signals to effectively increase bone mineral density in children with disabling conditions. Following only six months, the subjects who stood on a placebo device lost approximately 12% of their bone density from the tibia, while the subjects on the active device gained 6%. Over the course of longer treatment period, harnessing bone’s sensitivity to these stimuli may provide a non-pharmacological treatment for bone fragility in children.
Dr. Rubin added: “We are very excited with the results which indicate that these mechanical signals can prevent bone loss in the post-menopausal women, as well stimulate bone gain in children with osteoporosis. While the results are preliminary, it is exciting to see that our basic science shows clinical promise in treating the disease. To stop bone loss without the use of drugs may offer an alternative to pharmacologic therapies that require decades of committed use.”
Dr. Rubin’s work represents a critical step in establishing new therapies for osteoporosis that are non-invasive, based on the normal physiology of the musculoskeletal system, and require no drug regimens.
