Osteoporosis

Osteoporosis (porous bone) is a major health threat for upwards of 30 million women in the United States, according to the National Institutes of Health Osteoporosis and Related Bone Diseases National Resource Center.

Another "silent" disease that strikes without causing readily recognizable symptoms, osteoporosis is a progressive condition that causes bones to become thin. As bones lose density, or mass, the chances of hip, spine and wrist fractures increase dramatically. One out of every two American women will have an osteoporosis-caused fracture during the span of her lifetime. The disorder, which is preventable and treatable but incurable, is sometimes said to be a pediatric disease with geriatric consequences. When women fail to reach their peak bone density during childhood and teenage years -- important times for building bones -- they are more apt to experience osteoporosis in later life.

Bones are made up of collagen (a protein) and calcium, a combination that promotes strength and flexibility. All through life, old bone is naturally removed and new bone is added to the skeleton. But during youth and adolescence, new bone is added faster than old bone is removed -- a process that continues until maximum bone density and strength are achieved. While bone mass can increase until the third decade of life, 97% of peak density is reached by age 18. Once optimum bone mass is reached, the body reverses itself and bone removal begins to outstrip bone addition. For women, bone loss is fastest in the years immediately following menopause. When bone removal happens too fast or replacement happens too slowly, osteoporosis develops.

Calcium intake during childhood and adolescence -- along with adequate Vitamin D to facilitate calcium absorption -- is a key factor in bone growth. Yet, studies indicate that in the United States girls and young women consume less than half the amount they need from food to build and maintain healthy bones over a lifetime.

Advanced stages of the disease may result in severe back pain, loss of height and stooped posture. However, because symptoms most often do not present themselves, many women do not realize they have weakened bones until a fall causes a fracture or break. Bone thinning is a natural part of aging. While the condition can be slowed, osteoporosis cannot be permanently stopped.

Prevention

Taking steps to prevent bone density loss is helpful no matter what your age or condition:

  • Get enough calcium and vitamin D. Premenopausal women and postmenopausal women on HRT should have at least 1,200 milligrams (mgs) of calcium and 400 international units (IU) of vitamin D every day. Postmenopausal women not on HRT and those at risk of getting osteoporosis from taking steriods should get 1,500 mgs of calcium and 800 IU of vitamin D daily. Men under age 65 should consume 1,000 mgs of calcium every day and men over age 65, 1,500 mgs. Good sources of calcium include milk; low-fat plain yogurt; Swiss, cheddar and ricotta cheese; broccoli; canned salmon with the bones; orange juice and tofu. If you find it hard to get this much calcium from your diet, try calcium supplements.
  • Exercise, which helps build strong bones and slow bone loss. It is helpful no matter when you begin, but it has the greatest benefits when you start young and do it throughout your life. Strength training lets you build the muscles and bones in your arms and upper spine. Weight-bearing exercise (walking, jogging, running, stair climbing, skipping rope, skiing and impact-producing sports) helps the bones in your legs, hips and lower spine.
  • Don't smoke. Smoking speeds bone loss, perhaps by lowering how much estrogen a woman's body makes and by reducing the calcium absorbed by the intestine.
  • Consider hormone replacement therapy (HRT). HRT is the best way to reduce a woman's risk of osteoporosis during and after menopause.
  • Avoid drinking too much alcohol. Having more than two alcoholic drinks a day may cut bone formation and the body's ability to absorb calcium. There's no clear link between limited alcohol intake and osteoporosis.
  • Limit caffeine.

Screening

Early detection of osteoporosis is possible with a state-of-the-art dual energy X-ray absorptiometry (DEXA) scanner to measure bone density. DEXA scanning is a simple, painless way to measure bone loss. In fact, a scan of the entire body can take as little as four minutes. DEXA scanning is the preferred method for measuring bone mineral density. This scan detects even small changes in bone mass more precisely than other tests, and it can be used to examine both the spine and the extremities.

Treatment

Hormone replacement therapy (HRT) is the best way to prevent osteoporosis in women. HRT does have side effects, including an increased risk of blood clots and gallbladder and heart diseases. Taking HRT as a combination therapy - estrogen with medroxyprogesterone acetate (such as Prempro) - for several years or more may increase your risk of breast cancer. All combination HRT regimens can cause irregular vaginal bleeding, particularly during the first year of use. More study is needed to learn if estrogen-only therapy increases your risk of breast cancer. The long-term benefits of HRT are, therefore, under intense scrutiny.

If HRT is not for you, other prescription drugs can help slow bone loss and may even increase bone density over time. They include:

  • Bisphosphonates. These can reduce bone breakdown, preserve bone mass and even increase bone density in the spine and hip. The best known of these drugs is alendronate (Fosamax). Studies show it may cut the risk of hip and spine fractures in half. Etidronate (Didronel) is also sometimes given to help prevent bone loss.
  • Raloxifene. This imitates estrogen's good effects on bone density, without some of the increased cancer risks. Hot flashes are a common side effect. You shouldn't use this drug if you have a history of blood clots.
  • Calcitonin. Produced by the thyroid gland, calcitonin may slow bone loss and prevent spine fractures, but not hip fractures. It's given as a nasal spray, and about 12% of those who use it develop nasal irritation. It is usually given to those who are at high risk of fracture but cannot take estrogen or bisphosphonates.
  • Tamoxifen, a synthetic hormone used to treat breast cancer. Although it blocks estrogen's effect on breast tissue, it has an estrogen-like effect on other cells, including bone cells. It may have serious side effects.
  • Statins. Ordinarily this class of drugs is used to lower cholesterol levels, but some studies have shown that women who take statin drugs for at least a year may also lower their risk of bone fractures. Because research is ongoing, the drugs are not routinely given for osteoporosis. Side effects include potential reversible liver damage and, rarely, muscle inflammation.

Resources at Cedars-Sinai

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