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Medically Reviewed On: January 30, 2004

Published on: January 30, 2004

By Christine Haran

Over the last year and half, the use of postmenopausal hormone therapy has declined dramatically. The drop followed the release of a widely reported study that showed an estrogen/progestin combination increased the risk of breast cancer, heart disease and stroke. Many women had been taking postmenopausal hormone therapy to alleviate symptoms of menopause such as hot flashes, but many also took it to protect themselves from a variety of health problems, including fractures due to the bone condition osteoporosis.

Although hormone therapy is no longer recommended for the treatment of chronic conditions such osteoporosis, experts say women can't afford to forget about their bone health. Osteoporosis causes about 1.5 million fractures a year, many of which can end up disabling people and forcing them into a nursing home.

Below, Nelson Watts, MD, the director of the University of Cincinnati Bone Health and Osteoporosis Center and the immediate past president of the American College of Endocrinology, explains how postmenopausal osteoporosis is diagnosed and reviews the many treatment options other than postmenopausal hormone therapy.

What is postmenopausal osteoporosis?
Osteoporosis is best defined as a disorder of reduced bone strength that predisposes to fractures that can occur during daily activities such as pushing, pulling, lifting, bending, walking and falling.

Why does rapid bone loss occur after menopause?
Estrogen protects against bone loss. There is, in all of us, an age-related bone loss that starts probably in the 30s or 40s. With menopause, the drop in estrogen is associated with an accelerated bone loss that goes on at the rate of 1 percent to 2 percent per year for possibly 5 to 10 years. So it's possible for a woman to lose 20 percent of her bone mass during that period.

So if she goes into that period with a good bone mass that she acquired when she was young, that 20 percent bone loss will not cause problems. But if, as a young person, she didn't get enough calcium or vitamin D or wasn't physically active, or she had genetics that limited her peak bone mass, then even 10 percent bone loss could be a problem for her.

What are risk factors other than age?
Cigarette smoking increases the likelihood of having low bone density and the likelihood of having fractures. Then there is a long list of conditions, including the overactivity of the parathyroid and thyroid glands; lung diseases like asthma or emphysema; and gastrointestinal diseases like celiac disease and Crohn's disease, which interferes with the body's ability to absorb calcium and vitamin D. Some medications that might cause osteoporosis include prednisone or other corticosteroids. And aromatase inhibitors, which are used to treat some breast cancers, reduce estrogen levels to almost zero, which causes bone loss.

And women with a family history of the disease, who have low body weight, or who are tall are also at risk for fractures.

What are the most common fractures?
There are about 1.5 million fractures due to osteoporosis each year in the United States. About half of those are spine fractures. There are about 250,000 hip fractures a year. Hip fractures are more serious because they tend to affect older people who have other diseases. The mortality after hip fracture may be as high as 20 percent, and about 50 percent of hip fracture survivors are not able to return to fully independent living, and maybe 20 percent will require long-term nursing home care. There are about 250,000 forearm fractures, and then 250,000 at other sites.

Are there any symptoms of osteoporosis?
If you have a wrist or hip fracture, you know it and you'll get medical attention. But with the spine fracture, you may not know it because you might not have pain. Patients with a spine fracture lose height and that can crowd their internal organs causing problems with breathing and digestion. They also develop something called kyphosis, forward curvature of the upper spine. It's also called a dowager's hump.

How is osteoporosis diagnosed?
The only way to identify people who have osteoporosis before they start having fractures is by measuring bone density. Almost 10 years ago, the World Health Organization (WHO) came out with a classification that can be used to diagnose postmenopausal osteoporosis. Osteoporosis for postmenopausal, Caucasian women is defined as a bone density value, or T score, that is at least 2.5 standard deviations or more below the young adult mean. In terms that may be more understandable, those would be values that are 25 percent to 30 percent below the bone density of the average 30-year-old.

Theses values are often misapplied to younger women and men, and even to children.

What does a borderline reading mean?
Osteopenia is used to describe a bone density value between -1 and -2.5. But I am on a personal crusade to try to eliminate that term because it's less than helpful. Osteopenia is not a diagnosis; it's simply a numeric classification.

With values that are between -1 and -2.5, I encourage the physician to consider the circumstances. So people who are in the upper part of a borderline range (for example, -1.0 to -1.5) are probably healthy. For patients who are getting close to that -2.5 number, I say, "Oh, this is low, not just borderline." And if the patient has risk factors for fracture over and above low bone density, such as older age, a family history of osteoporosis or low body weight, then that patient would probably benefit from treatment.

How is bone density measured?
There are a variety of ways to measure bone density, but to use the recommended WHO classification, it needs to be measured with a technique called central DEXA, which is an abbreviation for dual energy x-ray absorptiometry. This is a painless test that takes about five minutes. It has very little radiation exposure. It measures the central skeleton, the spine and the hips, which are sites that are commonly affected by osteoporotic fractures.

There are machines out there that will measure bone density in the heel, in the finger, in the forearm. The problem with those devices is that the scores that we get with them cannot be used with the WHO numbers. So if you have a heel test and you're at -1.5, your hip might be -2.5. So these tests tend to under-diagnose osteoporosis.

When should bone density be tested?
It's important to think about bone density testing in two different frameworks: as a medical test and as a screening test. It's certainly an appropriate medical test in people who have certain condition or take medications that put them at risk. And it's certainly appropriate to use as a medical test in people who have signs of osteoporosis, such as fragility fractures or height loss.

Screening, however, is testing people who are healthy. What is currently recommended is that healthy women should begin testing at age 65. Postmenopausal women who have risk factors for osteoporosis should be tested earlier.

When should someone over 65 have their bone density test repeated?
The answer there depends on what the initial test shows. I have some bone density reports where the patient's bone density at age 65 looks so good that there's no need to ever repeat this study unless there is some new indication. There are others who look good, but if they lose bone a little faster than average might get in trouble in, say, five or 10 years.

Do you ever recommend menopausal hormone therapy to women with osteoporosis?
What we learned from the Women's Health Initiative was that giving a specific type of hormone therapy to postmenopausal women without symptoms tends to do more harm than good. There were some benefits: There were fewer fractures and fewer cases of colon cancer. But for as many of those as were prevented there were more cases of heart attack, breast cancer, blood clots, and a somewhat more rapid appearance of dementia, like Alzheimer's disease. So on balance the idea of a healthy postmenopausal woman taking estrogen for protection against osteoporosis or any other kind of chronic condition doesn't seem to make sense because of this unfavorable balance of risks and benefits.

When I see a patient who already has osteoporosis, I don't think about estrogen therapy among the options. There are other medications that are equally effective that seem to have a better risk/benefit profile.

What strategy do you recommend for a woman with low bone density who has stopped taking menopausal hormone therapy?
Women who take estrogen for menopause for, say, five years or longer, and then stop, will have rapid bone loss. Within the first year off estrogen, it may be as much as 5 percent or 6 percent bone loss. So if a woman was taking estrogen for osteoporosis and has already had a bone density test and been diagnosed with osteoporosis, then it would make sense for her to change to one of the other medications at the time that she's stopping estrogen.

For a woman whose bone density is just borderline low, you would at least want to monitor the bone density and see where they're going, and then start another medication if it drops low.

What are the treatment options that improve bone density?
We have five choices. We have Evista (raloxifene); Miacalcin (calcitonin) nasal spray; and Forteo (teriparatide). Then we have two bisphosphonate drugs, Fosamax (alendronate) and Actonel (risedronate).

How can people prevent osteoporosis?
Vitamin D, calcium and weight-bearing activities are important for bone health for anyone. Walking is terrific weight-bearing activity. I see many people without osteoporosis who jog and fall and break bones, so I don't recommend people take up jogging if that's not something they enjoy anyway. For osteoporosis, resistance exercises such as those performed with stretchy, rubber bands may also be helpful. For older people, any activities that help their reaction time can reduce their risk of falling, or if they do happen to fall, it improves their protective reflexes. Activities like tai chi have also been shown to reduce the risk of falling.

People have said that osteoporosis is a disease that shows up in older age, but it really starts in infancy. So getting enough calcium and vitamin D and staying physically active is something that should be striven for lifelong.