Osteoporosis
Osteoporosis is a disease, more common in women, that causes bones to become fragile and more susceptible to breaking. It is a real condition with serious effects on women's health and quality of life. Some women -- most commonly those who don’t have good access to health care -- experience fractures that could have been prevented if their osteoporosis had been treated. At the same time, not every woman who is warned about bone thinning needs to be worried. Companies that make drugs for osteoporosis have conducted advertising campaigns for women and health care providers that have created fear and led many women who don’t need the drugs to take them, despite serious side effects and risks.
In recent years, many new osteoporosis drugs have become available, creating a dilemma for women trying to decide which, if any, of these medications they need. Specifically, women want to know when it is appropriate to take a drug for osteoporosis, and which treatments are safest and most effective. The National Women's Health Network believes that the focus of efforts to promote bone health should be on preventing fractures rather than preventing loss of bone mineral density in women who are otherwise at low risk of experiencing a fracture. As you’ll read below, drugs are not always the best approach.
We’ve developed this fact sheet to help women understand several aspects of osteoporosis – what it is, screening tests, treatment and prevention with prescription drugs, and alternative approaches to prevention. It can help women make informed decisions about which osteoporosis drug to use, and if they need drug treatment at all.
What is osteoporosis?
Osteoporosis literally means porous bone. Throughout life, there are constant changes in the structure of bones. A natural process breaks down bones and builds them back up again at the microscopic level. Children and young adults build more bone than they break down. Pregnant women release bone to transfer needed minerals to the developing fetus and then build their own bone strength up again after giving birth. After age 35-40 all adults begin to lose bone as the breaking down process overwhelms the building process. For a few years around the time of menopause, women lose bone more quickly, possibly because they no longer need extra stores of minerals to support a developing fetus.
Osteoporosis occurs when the natural process of aging goes too far and bones become weak and fragile. Osteoporosis has several causes – age alone can be a cause of osteoporosis, especially in people who didn’t build up their bones to their fullest potential during childhood and young adulthood. Medicine can cause osteoporosis – taking high doses of steroids over a period of months can cause significant bone loss, for example. Removing women’s ovaries increases their risk of getting osteoporosis. Inactivity can cause osteoporosis, too – astronauts and people who are not able to walk briskly are more likely to develop fragile bones.
People who have osteoporosis are at greater risk for fracturing their bones, especially in the hip, vertebrae (spine) and wrist. Hip fractures lead to hospitalization, can take a long time to heal, and many women never fully recover from them. Individual vertebral fractures can be completely painless and cause no problems at all, but if multiple fractures develop in the spine it can be very painful and restrict women’s ability to move without serious discomfort.
Osteoporosis screening
In the 1980s, women’s health advocates were concerned that the medical community had overlooked the effect of bone fractures on older women’s quality of life. We advocated for change — but today the pendulum has swung to the other extreme. For more than a decade, big drug companies have used promotional campaigns to convince health care providers and women that osteoporosis not only affects older women, but also those at middle-age. Despite the fact that independent medical experts recommend women not be screened for osteoporosis until age 65 unless they have an unusual risk factor like long-term steroid use, osteoporosis screening is now widely promoted by physicians and drug companies for women in their 50s and even 40s.
The most common screening tool is a DEXA X-ray scan, which measures bone mineral density in the hip or spine. DEXA results compare a woman’s bone density to that of a healthy young adult (almost guaranteeing the scan will reveal bone loss, since everyone loses bone with age). If a woman’s bone density is significantly lower than a young adult’s, she is diagnosed with osteoporosis. Some clinicians are now warning women with bone density that is only slightly lower than the young adult average that they have “osteopenia” — a term that describes reduced bone density but is neither a disease nor disorder.
DEXA machines are safe and pose no health risks, but the push to use them earlier and diagnose osteopenia can lead to early and unnecessary treatment. As a result, women end up taking expensive drugs for decades that may have serious risks and/or side effects. Moreover, while the scan can predict fracture risk in the short-term, it cannot accurately predict the risk of fracture occurring decades in the future; thus, a scan taken at age 45 generally has no value for predicting what may occur when the woman is 70 (when debilitating fractures are most likely to occur).
In addition, the accuracy of DEXA machines may not be as good in real life as it has been shown to be in carefully controlled research settings. Specialists have observed that very small changes in positioning of the hip and spine for BMD studies result in large differences in T scores. There is also a lot of variation between machines even from the same manufacturer. These differences caused by error may be as big as any change in bone density that a woman is actually experiencing. We recommend that women wait at least two years between scans and that women getting repeat scans have them done on the same machine, if possible.
Questions also exist about the value of such screening for women of color. The original DEXA studies did not include any women of color, so there’s a lack of good information about normal bone density scores, and what score might indicate concern about the risk of bone fractures, for these populations. African American women typically have denser bones and lower fracture rates than White women, while Asian American women typically have thinner bones, but also have lower fracture rates than White women. NWHN believes that research is needed on both osteoporosis and the use of DEXA scans in women of color, and until such research has been conducted we recommend that women of color approach screening with caution.
Drug Treatments
Women diagnosed with osteoporosis or osteopenia are usually told they need to take prescription medication to prevent further bone loss and reduce the risk of fractures. The most common drugs are:
Hormones
The Food and Drug Administration (FDA) has approved estrogen and progestin treatment to prevent osteoporosis — but not to treat it. Both estrogen alone and combinations of estrogen and progestin reduce women’s risk of osteoporosis and bone fracture. But, the hormones also increase the risk of breast cancer, heart attack, stroke, and pulmonary embolism. So, these hormones should be the last choice for osteoporosis prevention and should be used only when other prevention methods are not safe or appropriate for a particular woman.
Two other hormones have been approved to treat osteoporosis: teriparatide and calcitonin. Teriparatide (brand name: Forteo) is a derivative of human parathyroid hormone (PTH), the primary regulator of calcium and phosphate metabolism in bones; a daily 20 mg injection has been shown to stimulate new bone formation and prevent spine, hip, wrist and other bone fractures in women with osteoporosis. Teriparatide is generally used only for women with severe osteoporosis, because most people don’t want to get shots every day and side effects can include nausea, leg cramps, and dangerously high calcium levels. It’s also quite expensive, and some insurance companies are reluctant to cover it.
Calcitonin (brand names: Fortical or Miacalcin; not the same as calcium supplements) has been shown to prevent fractures of the spine but not of the hip and wrist. It is approved to treat women with osteoporosis, but its approval was based on weaker evidence than more recently approved drugs, and its use is not generally recommended. Women who take calcitonin must watch their intake of foods with high calcium levels (e.g., milk, cheese), as excessive calcium can be dangerous. Calcitonin is administered through a nasal spray; side effects may include nasal congestion and nausea.
Bisphosphonates
The FDA has approved six bisphosphonates to prevent bone loss and fractures in post-menopausal women: alendronate (Fosamax), etidronate (Didronel), ibandronate (Boniva), risedronate (Actonel), tiludronate (Skelid), and zoleldronic acid (Reclast, Zometra). Some are taken daily, others are formulated for weekly or monthly use. Bisphosphonates seem to have fewer risks than hormones, at least in the first five years. But the drugs haven’t been around very long and little is known about either the effects of taking them for more than 10 years, or of their use in pre-menopausal women. We now know that the fracture prevention benefit of at least one bisphosphonate (alendronate) persists for many years after stopping the drug. But whether it could last long enough to be taken at middle-age and reduce the risk of fractures in old age is unknown.
Several possible health problems are associated with bisphosphonates. First, there are questions about the effect of these drugs on women’s hearts. The FDA announced in January 2008 that it was conducting a safety review of the drugs, initiated after studies reported that women taking them had higher rates of irregular heart rhythms (atrial fibrillation) than other women. Second, women may experience severe bone, joint, and/or muscle pain after starting a bisphosphonate. The FDA advises patients with such pain to consider discontinuing the drug, which usually causes the pain to go away. Third, there have been reports that the jaw tissue of some women taking bisphosphonates dies (jaw necrosis), which can necessitate removal of the jaw bone. Fourth, very recent reports have raised concern about what may be an association between bisphosphonates and unusal fractures of the thigh bone. Finally, bisphosphonates can cause severe heartburn and ulcers and damage the stomach and esophagus if not taken in a very careful regimen (on an empty stomach, with a full glass of water, while sitting upright for up to an hour).
Selective Estrogen Receptor Modulators
The FDA has approved raloxifene (Evista) to prevent and treat osteoporosis. The drug has been tested more extensively than biophosphonates and although it reduces the risk of spine fractures, it doesn’t seem to reduce hip fracture risk. It also raises different safety concerns that include increased risks of blood clots, hot flashes, nausea, and leg cramps. In September 2008, the FDA held an advisory committee meeting to discuss an application to approve another SERM, lasofoxifene, for the treatment of osteoporosis in postmenopausal women. Research reviewed by the FDA showed that lasofoxifene appears to reduce spine fractures in the first three years of use. Like raloxifene, it increases the likelihood of blood clots, and it also increases vaginal bleeding and women taking the drug were subjected to more invasive procedures such as endometrial biopsies, D&Cs and even hysterectomy. The NWHN recommended to the FDA that approval of lasofoxifene be delayed until the agency can fully review research that extended use to five years so that we’ll know more about the effects and effectiveness of using the drug for longer. NWHN also expressed concern that Pfizer, the company that makes lasofoxifene, will encourage women to take this drug for pother uses that haven’t been fully evaluated by the FDA.
Alternatives
Alternatives to drugs exist for making and keeping bones strong. The National Institutes of Health’s 2000 Consensus Statement on Osteoporosis reviewed the research on osteoporosis prevention and treatment and found strong scientific evidence that calcium and Vitamin D intake are crucial to develop and preserve strong bones.
Regular exercise (especially resistance and high-impact activities) contributes to the development of bone mass. Other promising interventions focus on preventing fractures: balance training reduces the risk of falling, which is often responsible for broken bones in older people. A few small studies have shown that hip protectors provided along with training on how to use them can help reduce the risk of fracture if a fall occurs. Large randomized trials didn't find any benefit, though. Other practical ways to reduce the risk of falling include making sure that vision prescriptions are up-to-date, checking prescriptions for drug interactions that might cause dizziness, eliminating fall-causing hazards in the home (like slippery rugs), and wearing appropriate shoes.
The Bottom Line
Drug companies are clearly trying to expand the market for osteoporosis drugs; their latest efforts target “non-traditional” populations (like younger women and men) for screening. Many women under age 65 without critical risk factors are being screened for osteopenia and osteoporosis, despite the fact that early screening has not been shown to prevent most serious fractures. The NWHN encourages women under age 65 to reject bone density screening unless they have unusual circumstances that increase their risk.
In addition to thinking carefully about their own risk of experiencing a serious fracture, women need to consider safety issues when deciding whether to take osteoporosis drugs. Also, the treatment’s duration is critical in determining its effectiveness: when a woman stops taking certain osteoporosis prevention drugs, the preventive effects are quickly lost. Don't hesitate to ask your health care provider about the safety and efficacy of any osteoporosis medication and whether non-drug alternatives might be just as effective, based on your personal history and current health status. For more information go to the National Institutes of Health Osteoporosis and Related Bone Diseases Resource Center's website.
REFERENCES
1. Osteoporosis Prevention, Diagnosis, and Therapy. NIH Consensus Statement 2000 March 27-29; 17(1): 1-36.
updated 9/08
