Throughout life, our bones are in a constant state of turnover -new bone replaces old. In growing children, more bone is added than removed. By age 20, the skeleton has matured and the rates of bone growth and removal are equal. At 40, bone loss begins to exceed our ability to replace it. If losses reach a critical level, bone may be seriously weakened. This is osteoporosis.
The problem may first become apparent after a fall, with a break in a hip or wrist. Collapse of weakened vertebrae can cause severe curvature of the spine, or dowager’s hump. Bending, coughing or sneezing can cause fracture of spinal vertebrae or ribs. The excruciating pain of a spine fracture can last many weeks. Dull, nagging pain may persist for years, and the patient remains at high risk for additional fractures.
Women bear the greatest risk of osteoporosis. At menopause, loss of estrogen hormone makes the body less efficient at absorbing calcium and incorporating it into bone. Calcium deficiency, smoking, a family history of osteoporosis, excessive use of alcohol, and lack of exercise all increase the chance of the disease.
Fortunately, we have the ability to detect the disorder through a painless test called a DXA scan. Using a small amount of x-ray, bone density can be measured at the spine, hip and forearm. The effects of treatment can be monitored by repeat testing. For most women, a scan is recommended by age 65; for men, 70.
Prevention starts with making sure the patient has an adequate intake of calcium and vitamin D. Many adults have limited intake of dairy products, and need calcium supplements. A simple blood test can detect vitamin D deficiency. Many of my seniors need to take a supplement of this “sunshine vitamin.”
Estrogen replacement can slow or prevent bone loss in women, but the risks of estrogen treatment, including cancer and blood clots, have limited the use of hormone therapy. Alternate forms of estrogen, called SERMs, are appropriate for some women with low bone density to prevent osteoporosis.
Fortunately, we now have a number of medications that can effectively treat osteoporosis. A class of drugs called bisphosphonates includes commonly used medications such as alendronate (Fosamax), ibandronate (Boniva), and risedronate (Actonel). An intravenous drug, zoledronate (Reclast), can be given as a one half hour infusion once a year. This avoids the stomach and esophagus irritation that the oral drugs can cause and is much more efficiently absorbed into bone. Injections of denosumab (Prolia) can also be administered, twice yearly. In severe cases, a daily hormone injection of teriparatide (Forteo) is very effective in helping to stimulate bone growth. Other new medications are in development.
Not to be overlooked is the importance of preventing falls. Walking is a favored form of weight-bearing exercise. Yoga and tai chi emphasize balance. Practical measures include keeping a well-lit pathway from bed to bath during the night, free of throw rugs and other obstacles.
The recognition, treatment and prevention of osteoporosis can help to avoid debilitating fractures. Patients should carefully review their test results with the doctor, to help determine which options are best.
Here are some suggested references for more information on this topic:
Alan R. Schenk, M.D. FACP