Yoga and Osteoporosis: Another Osteoporosis Drug Linked to Increased Spontaneous Femur Fractures

Editor’s Note: It’s a terrible irony—the very drug that’s supposed to be preventing hip fractures for people with osteoporosis might indeed be increasing the risk of femur fractures for some. This has long been a highly publicized effect of Fosamax and other bisphosphonates (the leading class of osteoporosis drugs). According to a New York Times article from June, 2016, millions of Americans are opting not to take the osteoporosis medication. Now new research questions the safety of another drug, Prolia, which in some studies led to twice the number of femur fractures compared to a placebo. And strangely, while European doctors have been informed of the increased risks, so far U.S. doctors have not.

In this insightful article, Yoga U Presenter Dr. Loren Fishman updates on the controversy of osteoporosis medications and why yoga might be your best bet for preventing fractures. If you’re interested in joining Dr. Fishman’s ongoing study on Yoga for Osteoporosis, go here to see an update on the study on and how you can join.

The drug Prolia is an injectable osteoporosis medication, which targets a molecular complex known as RANK that activates the osteoclasts that break down bone. In the body, RANK floats around stimulating osteoclasts, and makes more of them work harder to reduce bone density.

In other words, RANK increases the activity of the osteoclasts, the cells that dissolve bone, and Prolia reduces the activity of RANK.  In this respect, Prolia does exactly what the bisphosphonates such as Fosomax or Boniva do, but it does so more directly by bypassing the stomach, a trouble spot for the orally administered osteoporosis medicines.

The Risk of Osteoporosis Drugs

After a great deal of excitement and publications in the New England Journal of Medicine, Prolia was approved by the FDA in 2010. This despite the fact that worries about the extra fractures of the femur that were associated with the use of Prolia started popping up in 2009!  Subsequent studies found the incidence of femoral fractures to be nearly twice as common in research participants taking Prolia as in a comparable group of patients receiving a placebo.  In general, viewing cost-benefit analyses, a British study found Prolia to be no better than the bisphosphonates. (1)

Unfortunately, no American physicians have yet received official notice of the tendency to increase femoral fractures.(2) There is now a special name for the type of breaks in bones caused by these osteoporosis medications: AFF (atypical femoral fractures). They are defined by seven major features.  Most significantly, they look differently than the fractures that normally occur, having characteristics that suggest an internal process rather than an external traumatic process. Recently a Canadian article reported a fracture of the tibia, the shin bone, that met all of the criteria for AFF, except of course location in that it was a different bone, suggesting that other weight-bearing long bones could suffer the same fate. (3)

Another article defends the use of the injected osteoporosis drug, stating that the association between Prolia and fractures is yet unproven, and even if it were proven, the treatment would still be worthwhile. (4)

This point of view is hard to understand, since the medication’s purpose is to reduce fractures, yet it has been shown to double the incidence of fractures involving the femur, the most dangerous and deadly of all fractures associated with osteoporosis.

Missing Links no longer Missing

Fractures have been correlated with bisphosphonate medications, but no one has seen exactly how.  New studies reveal how disrupting nature’s balance is not a good thing.

Many osteoporosis medicines that suppress the natural give-and-take in bone formation and resorption have been shown to increase fracture risk.  Scientists and physicians have long assumed that this is a disruption of natural processes, but assumptions are not the stuff of science.  Two recent studies illustrate that there is indeed a direct causal connection.

* First, scientists have identified intermediate cells that develop into osteocytes, the cells that make new bone after damaged or diseased bone has been resorbed.
* Secondly, there is a molecule secreted by the osteoclasts, (the cells that dissolve bone), that stimulates growth and activity of the intermediate cells that will lay down new bone exactly where the old bone has been resorbed. Reversal cells, which turn into osteocytes (the cells that make bone), have been found where osteoclasts have done their work. (5) CTHRC1, made by the osteoclasts, was seen to stimulate such cells to transform themselves into osteocytes.(6)

So the cycle is complete: Osteoclasts perform their janitorial function, taking damaged and diseased bone up and sending its protein back into the general circulation, and leave a marker that stimulates other cells to come in and replace the bone. When the medicines retard this natural process, diseased and damaged bone accumulate, causing the very fractures they were intended to prevent.  

References

(1)  Scotland G, Waugh N, Royle P, McNamee P, Henderson R, Hollick R.”Denosumab for the prevention of osteoporotic fractures in post-menopausal women: a NICE single technology appraisal.” Pharmacoeconomics. 2011 Nov;29(11):951-61.
(2)  Michael Monheit, denosumab-prolia is another osteoporosis drug causing femur fractures/ August 7, 2013. http://central-pennsylvania.legalexaminer.com/fda-prescription drugs/.
(3)  Bissonnette L, April PM, Dumais R, Boire G, Roux S. “Atypical fracture of the tibial diaphysis associated with bisphosphonate therapy: A case report.” Bone. 2013 Jul 17;56(2):406-409.
(4)  Rizzoli R, Akesson K, Bouxsein M, Kanis JA, Napoli N, Papapoulos S, Reginster JY, Cooper C. “Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report.” Osteoporos Int. 2011 Feb;22(2):373-90.
(5)   Andersen TL,  Abdelgawad ME, Kristensen HB, Hauge EM, Rolighed L, Bollerslev J, Kjærsgaard-Andersen P, Delaissero J-M “Understanding coupling between bone resorption and formation: Are reversal cells the missing link?” American Journal of Pathology. Volume 183, Issue 1 (July 2013).
(6)   Takeshita S, Fumoto T,  Matsuoka K, Park K, Aburatani H, Kato S, Ito M, Ikeda K.”Osteoclast-secreted CTHRC1 in the coupling of bone resorption to formation” J Clin Invest. August 2013.