Adults reach peak bone mass in their 30s, followed by a slow decline. Women pay a higher price than men because on average they have smaller frames than men–with less bone to start with. When women hit menopause in their late 40s or early 50s the rate of bone loss speeds up for a few years, leaving many women at risk for fractures.
To some degree having higher estrogen levels prior to menopause helps women. And until recently many women have taken hormone replacement therapy to maintain bone density. Following negative findings about the increased risks of heart attack and stroke associated with HRT, physicians are not as likely to prescribe it for some patients depending on other risk factors. Other prescription drugs are available that can help prevent bone loss and actually increase bone density. Biphosphanates, a class that includes Fosamax (alendronate), Actonel (risedronate), Boniva (ibandronate) and Reclast (zoledronic acid) have been shown to prevent bone loss and promote the building of new bone.
Just about every woman can assume that she needs to follow the basic guidelines of getting recommended amounts of calcium and vitamin D for her age plus plenty of weight bearing exercise to ensure adequate bone density. But how does she know if she needs a bone-building drug as well?
A non-invasive test known as dual energy x-ray absorptiometry (DEXA) is considered the gold standard for measuring bone density and the future risk of fractures. DEXA can be used to measure bone density at the wrist, hip and spine, all high-risk areas for fractures.
The definition of osteoporosis is based on how much bone mineral density varies from the average bone mineral density of a young adult. Expressed in T-scores, osteoporosis is diagnosed when the T-score is below -2.5. Scores of -1 to -2.5, indicate osteopenia, a less serious condition but an early warning that either lifestyle changes or medical interventions are necessary.
The advantage of DEXA is that it can provide an early warning of what is all too frequently a silent disease. For many women the first sign of osteoporosis is the broken wrist, hip or spine that comes with a fall on the kitchen floor.
The bisphosphanates are frequently prescribed for women who have suffered broken bones because of osteoporosis or who have low DEXA scores. A recent study found that too often patients quit worrying about getting adequate calcium and vitamin D when they start taking medication, assuming that the drug is taking care of the problem. Researchers found that bone-building drugs were much more effective when women also consumed recommended levels of calcium and vitamin D.
Raloxifene, a selective estrogen receptor modulator (SERM), has some of the benefits of estrogen but without the risk of breast cancer associated with estrogen replacement. It also increases bone mineral density and is prescribed for some women with osteoporosis. One negative side effect is that it can worsen hot flashes. Calcitriol is another medication that can be prescribed for osteoporosis. It is prescribed sometimes for women who cannot tolerate biphosphonates, but it has to be taken twice a day and requires monitoring of calcium levels.
While medications are effective, women can do much to help themselves. Lowering your risk by getting regular weight-bearing exercise and avoiding smoking and excess alcohol consumption. You should also consume the equivalent of one and one-half pints of reduced fat or fat-free milk or milk products per day as well as calcium-rich foods such as dried beans, green leafy vegetables, dried fruit and calcium-fortified orange juice. In order to use calcium effectively, the body needs vitamin D, which is most readily available through sunlight. Even though sunlight is the best method, taking a vitamin D supplement will also help the calcium you are taking to work more efficiently.
If you are planning for good health in the second half of life, make sure you include your bones in the blueprint. Bones are the frame that keeps your body strong and mobile. So be as attentive to your bones as you are to your skin. Keep feeding them the raw materials they need to renew and rebuild for a strong and active future.
Kerri Musselman, PharmD—Rev. 5/12/10 TNK
