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Osteoporosis

 

What it is


Ten million Americans—80 percent of them women —currently have osteoporosis, or "porous bones." Another 18 million have low bone mass, or osteopenia, a precondition to osteoporosis which puts them at increased risk. With the first of the baby boomers now heading into their golden years, the National Osteoporosis Foundation expects the number to soar to 41 million in the next 15 years. In fact, your risk of suffering an osteoporotic hip fracture alone is equal to your combined risk of breast, uterine and ovarian cancer.

Bone is a living tissue. Your body constantly breaks down and removes old bone while simultaneously forming new bone. Even well after puberty, your body adds more bone than it removes. Both men and women reach their peak bone mass sometime between the age of 20 and 30, when the balance starts to tip the other way and your body begins to lose bone mass at a faster rate than you can rebuild it. At menopause, consult with your physician to discuss risk factors and to explore what option is best for you. The drop in estrogen, which has a protective effect on bone, can make you lose as much as 20 percent of your bone mass in the first five to seven years of menopause.

Although osteoporosis can happen to any of your bones, it is most common in the hip, wrist, and in your spine, also called the vertebrae. Vertebrae are important because these bones support your body to stand and sit upright.

Symptoms



Osteoporosis in the vertebrae can cause serious problems for women. A fracture in this area occurs from day-to-day activities like climbing stairs, lifting objects, or bending forward, along with:

  • Sloping shoulders
  • Curve in the back
  • Height loss
  • Back pain
  • Hunched posture
  • Protruding abdomen

A small amount of height loss is a normal accompaniment of aging. Women who live into old age may lose about half an inch due to the degeneration of discs in the spine. They may also shrink a little due to poor posture and weakened back muscles. But loss of an inch or more in height, particularly when accompanied by the "dowager's hump," might signal osteoporosis and the presence of fractured vertebrae—and that's not normal. If women with these symptoms haven't already suffered a hip or wrist fracture, it's likely that they will, though drug treatments may help offset the risk. Half of all women over 50 are expected to experience an osteoporosis-related fracture at some point in their lives, but it doesn't have to be that way. Fractures are not a normal consequence of aging.

Who is at risk?

Although most osteoporotic women are older than 50 and well into menopause, women in their 30s—or even younger—can develop the condition if they have a history of anorexia or bulimia (which may cause amenorrhea and low calcium levels as a result of vomiting, purging and poor nutrition); if they are athletes training hard enough to become amenorrheic; or if they have low estrogen levels. Because osteoporosis is usually asymptomatic, it can sneak up on women, many of whom aren't diagnosed until they actually break a bone. For this reason it's called a "silent disease."

7 major risk factors

1. Eating disorders Since their nutrition is so poor, anorexics and bulimics deprive their bodies of calcium, bone's major building block. Anorexics often don't have enough body fat to menstruate, so their estrogen levels drop, too, increasing bone breakdown. This double whammy occurs when bone density should be still rising, so these women may never attain a normal peak bone mass.

2. Body size It is believed that thin women with small frames have lower bone mineral density (BMD), a measure of bone health.

3. Family history Researchers aren't sure osteoporosis is genetic, but it does seem to run in families. Having a mother or sister with it puts you at increased risk. White and Asian women have a higher risk as well.

4. Erratic periods/early menopause (whether from natural causes or a hysterectomy) Irregular periods translates into a lack of progesterone, a hormone needed along with estrogen for bone health. Estrogen reduces the rate of bone loss, while progesterone, when in the presence of estrogen, stimulates new bone formation. Athletes beware: Rigorous training and low body fat can trigger irregular periods or amenorrhea.

5. Some diseases Conditions like hyperthyroidism, hyperparathyroidism and chronic kidney, lung and gastrointestinal disorders are risk factors.

6. Long-term use of certain medications The number one culprit: corticosteroids to suppress inflammation. Steroid drugs prescribed for diseases like epilepsy, severe asthma, severe allergies and autoimmune diseases like lupus can also have an effect (nonsteroidal drugs prescribed for these diseases do not pose problems in terms of bone loss).

7. Excessive doses of thyroid hormone Normal replacement dosages for hypothyroid patients are perfectly safe, although super high doses prescribed by a doctor in certain rare circumstances can have an effect if prolonged.

Diagnosis

The most-reliable means of diagnosing osteoporosis is with a bone mineral density (BMD) test. The most-comprehensive test, using dual energy X-ray absorptiometry (DXA or DEXA), is a relatively quick, painless procedure that uses a very low dose of radiation (10 times less than you'd get on a round-trip, cross-continental flight) to measure the density of the hip and spine, where osteoporosis shows up first and is the most debilitating. Smaller machines using ultrasound to measure BMD in the extremities (typically the heel) are sometimes available at health fairs or in shopping malls, although experts debate their accuracy. One point is clear, however: If you have an ultrasound test that shows even marginal bone loss, talk to your doctor about having a DEXA scan as soon as possible.

Getting bone scans is especially important for women with major risk factors like menopause, eating disorders or prolonged amenorrhea. And experts believe many more premenopausal women could benefit from scanning, so those who don't know they've already lost bone can find out early.

You have osteoporosis if a scan reveals bone loss at any one site of at least 25 percent and osteopenia when results fall between 10-24 percent.

Treatment

Lifestyle changes and medical treatment are part of a total program to prevent future fractures. A diet rich in calcium, daily exercise, and drug therapy are treatment options. Good posture and prevention of falls can lower your chances of being injured.

These drugs are approved for the treatment or prevention of osteoporosis:

  • Alendronate (Fosamax®). This drug belongs to a class of drugs called biophosphonates and is approved for both prevention and treatment of osteoporosis. It is used to treat bone loss from the long-term use of osteoporosis-causing medications and is used for osteoporosis in men. In postmenopausal women, it has shown to be effective at reducing bone loss, increasing bone density in the spine and hip, and reducing the risk of spine and hip fractures.
  • Risedronate (Actonel®). Like Alendronate, this drug also is a biophosphonate and is approved for both prevention and treatment of osteoporosis, for bone loss from the long-term use of osteoporosis-causing medications, and for osteoporosis in men. It has been shown to slow bone loss, increase bone density, and reduce the risk of spine and non-spine fractures.
  • Calcitonin (Miacalcin®). Calcitonin is a naturally occurring hormone involved in calcium regulation and bone metabolism. Calcitonin can be injected or taken as a nasal spray. In women who are at least five years beyond menopause, it slows bone loss and increases spinal bone density. Women report that it also eases pain associated with bone fractures.
  • Raloxifene (Evista®). This drug is a selective estrogen receptor modulator (SERM) that has many estrogen-like properties. It is approved for prevention and treatment of osteoporosis and can prevent bone loss at the spine, hip, and other areas of the body. Studies have shown that it can decrease the rate of vertebral fractures by 30-50%.
  • Estrogen therapy (ET), or Hormone Therapy (HT). These drugs, which have been used to treat the symptoms of menopause, also are used to prevent bone loss.  But recent studies suggest that this might not be a good option for many women. The Food and Drug Administration (FDA) has made the following recommendations for taking ET and HT:
    • Take the lowest possible doses of ET or HT for the shortest period of time to manage symptoms of menopause.
    • Talk about using other osteoporosis medications instead.
  • Parathyroid Hormone or Teriparatide (Fortéo®). This form of parathyroid hormone is approved for the treatment of osteoporosis in postmenopausal women and men who are at high risk for a fracture. It helps new bone to form and increases bone density. It has been shown to reduce fractures in postmenopausal women in the spine, hip, foot, ribs, and wrist. In men, it can reduce fractures in the spine. A patient gives it to herself as a daily injection for up to 24 months.

 

Prevention

The best way to prevent osteoporosis is to make high-intensity weight-loading exercise a regular part of your workout, get enough calcium and—once you're in menopause—take hormone replacement or a drug that mimics estrogen.

Put on the weight

When it comes to weight-bearing exercise, it's best to comply with existing guidelines set by the American College of Sports Medicine, according to Daniel Kosich, Ph.D., an exercise physiologist and consultant to Aurora Denver Cardiology and a Shape contributing editor. Ideally, your weight-loading regime should include vigorous resistance training (free weights, machines, elastic resistance, water resistance, body resistance). Kosich recommends eight to 12 repetitions maximum (to temporary muscle fatigue), performing one to three sets two to three days a week. Kosich says exercises which are particularly helpful for preventing osteoporosis include squats, lunges and leg presses.

To really target the wrist, a common fracture site, Dianne Daniels, an exercise physiologist in New York City and author of Exercises for Osteoporosis (Hatherleigh Press, 2000) recommends doing push-ups, squeezing a rubber ball in your hand or wringing out a towel (one wrist flexes while the other extends).

Feed your bones

Even the best exercise plan won't work if you're not getting enough calcium. The latest adult recommendation is at least 1,000 mg a day (1,200 after age 65), although most Americans consume only about half that. Supplements can help you get your daily calcium requirements, but the mineral is most easily absorbed from foods. Dairy products such as skim milk, lowfat yogurt (1 cup provides 300 and 415 milligrams, respectively) and Swiss cheese are the richest sources, but broccoli, kale and oranges also contain the mineral. A healthful diet boosts bone in other ways, too, such as by providing vitamin D, as well as magnesium and vitamins C and K, all of which benefit the skeleton.

If you're not getting enough calcium through your diet, supplements can help. Calcium carbonate is the cheapest; taking it with food may improve absorption, but it sometimes causes gas and constipation. Calcium citrate costs a little more, but you can take it with or without food and it may cause less discomfort. Either way, don't take more than 2,500 mg a day or you may raise your risk of kidney stones. And don't take more than 500 mg at one time because your body can only utilize so much at once. The rest is merely flushed out of the body. Avoid supplements made with unrefined oyster shell.

To absorb calcium, you also have to get the Recommended Dietary Allowance of vitamin D (between 400 and 600 IU). Like magnesium and phosphorus, two other bone-healthy nutrients, this vitamin can be easily obtained by eating a balanced diet containing vitamin-D-fortified foods, plenty of calcium through milk, dairy products and calcium-fortified foods and juices, and by taking a multivitamin.

 

Quit smoking and limit alcohol

Both smokers and heavy drinkers have lower BMDs. Smoking may lower your estrogen levels, which results in bone loss, while heavy drinking interferes with nutrition, although a recent study showed that premenopausal women who consumed beer in moderation had significantly higher bone mineral densities than non-beer drinkers. Beer is a major source of silicon, a mineral strongly associated with bone health. But instead of pounding down four beers a day to reach the recommended 30 milligrams of silicon, try eating green beans, whole grains and bananas, all of which contain good amounts of the mineral.

Some doctors also warn against consuming large amounts of protein, sodium, caffeine and soft drinks like colas that contain phosphorus because they can leach calcium from the bones, although with adequate calcium intake, that effect may disappear.

 

Adapted from The National Women's Health Information Center (www.womenshealth.gov)