Newsletters

Winter 2009

New Ways to Make Bones Stronger

Osteoporosis is a disease that is characterized by reduced bone strength that results in increased risk of fractures (broken bones). The measurement of bone density is considered to be a surrogate of bone strength and fracture risk. In other words, when the bone density is low, the bones are weak and at high risk for fracture. Since fractures can be painful and result in long-term disability, loss of independence, and even death, we need to do all that is possible to prevent fractures. Although the risk of fractures can never be totally eliminated, there are things we can do to improve the odds.

Bone density in adults is determined by two factors- the peak bone mass (the best our bones ever were, usually occurring sometime in our 20s) and the rate of bone loss after that. To assure the best possible peak bone mass, a healthy lifestyle and good nutrition in childhood and adolescence are very important. To slow down the rate of bone loss later in life, we need to continue with regular physical activity and have a good intake of calcium and vitamin D. If osteoporosis or very low bone density is present, we may need medications to help. There are now many choices for osteoporosis medications, including a good one that is generic (very cheap!). However, scientists are continually searching for better and safer drugs to improve bone strength.

The recent trend in the drug treatment of osteoporosis is to use drugs that have long intervals between doses (now as long as one year) and that are easier to administer. Also, as we learn more about the workings of individual molecules that regulate the activity of bone cells, we have found new opportunities to develop new treatments.

One such drug that may be available for use by the end of 2009 is denosumab. It is given as a simple subcutaneous (just under the skin) injection once every 6 months. Research on this drug, conducted here at New Mexico Clinical Research & Osteoporosis Center and elsewhere, has shown that it makes bones stronger and less likely to break.

Another drug in development, odanacatib, is an inhibitor of an enzyme called cathepsin K. This enzyme, which is normally produced by osteoclast bone cells, dissolves the protein portion of bone in the process of bone remodeling. Since osteoporosis may be caused by excessive bone remodeling, a drug such as odanacatib that slows remodeling may improve bone strength and reduce fracture risk.

Other potentially useful drugs are ones that stimulate the formation of new bone in places where it has been lost. Researchers will continue to pursue all possible ways to improve bone strength and reduce the burden of osteoporotic fractures.

E. Michael Lewiecki, MD                                    
Lance A. Rudolph, MD

This page update 01/14/09