The word osteoporosis literally means "porous bones." It occurs when bones lose too much of their protein and mineral content, particularly calcium. Overtime, bone mass, and therefore bone strength, is decreased. As a result, bones become fragile and break easily. Even a sneeze or a sudden movement may beenough to break a bone in someone with severe osteoporosis.
To understand osteoporosis, it is helpful to understand the basics of bone formation. Bone is living tissue that's constantly being renewed in a two-stageprocess (resorption and formation) that occurs throughout life. In the resorption stage, old bone is broken down and removed by cells called osteoclasts.In the formation stage, cells called osteoblasts build new bone to replace the old. During childhood and early adulthood, more bone is produced than removed. After the mid-30s, bone is lost faster than it's formed, so the amount of bone in the skeleton slowly declines. Osteoporosis that occurs as an acceleration of this normal aging process is called primary osteoporosis. Osteoporosis that occurs because of other diseases or prolonged use of certain medicines is called secondary osteoporosis.
Osteoporosis occurs most often in older people. Women, however, are five times more likely than men to develop the disease. They have smaller, thinner bones than men to begin with, and they lose bone mass more rapidly after menopause (usually around age 50), when they stop producing a bone-protecting hormone called estrogen. In the five to seven years following menopause, women canlose about 20% of their bone mass. By age 65 or 70, though, men and women lose bone mass at the same rate.
- A number of factors increase the risk of developing osteoporosis. They include:
- Race. Caucasian and Asian women are most at risk for the disease, but African American and Hispanic women can get it too.
- Figure type. Women who are thin with small bones are more liable to have osteoporosis.
- Early menopause. Women who stop menstruating early because of heredity, surgery or heavy physical exercise may lose large amounts of bone tissue early in life. Conditions such as anorexia and bulimia may also lead to early menopause and osteoporosis.
- Lifestyle. People who smoke or drink too much, or don't get enough exercise have an increased chance of getting osteoporosis.
- Diet. Those who don't get enoughcalcium or protein are more likely to have osteoporosis.
Before making a diagnosis of osteoporosis, the doctor usually takes a complete medical history, conducts a physical exam, and orders x rays, as well as blood and urine tests, to rule out other diseases that cause loss of bone mass.The doctor may also recommend a bone density test. This is the only way to know for certain if osteoporosis is present and far it has progressed.
Ordinary x rays don't reveal bone loss until the disease is advanced and mostof the damage already has been done. Machines called densitometers, which are designed specifically to measure bone density, can catch the disease in earlier stages. The most accurate and advanced densitometers use a technique called DEXA (dual energy x-ray absorptiometry). People should talk to their doctors about their risk factors for osteoporosis and should discuss whether theyshould get the test.
For most women who've gone through menopause, hormone replacement therapy (HRT), also called estrogen replacement therapy, is an effective treatment for osteoporosis, as well as for relief of other menopause-related symptoms. HRT increases a woman's supply of estrogen, which helps build new bone, while preventing further bone loss. Some women, however, do not want to take hormones,because some studies show they are linked to an increased risk of breast cancer or uterine cancer. Whether or not a woman takes hormones is a decision she should make carefully with her doctor.
For people who can't or don't want to take estrogen, two other medications, alendronate and calcitonin, can be good choices. Both stop bone loss, help build bone, and decrease fracture risk by as much as 50%.
Unfortunately, much of the treatment for osteoporosis is for fractures that result from advanced stages of the disease. For complicated fractures, such asbroken hips, hospitalization and a surgical procedure are required. Though the surgery itself is usually successful, complications of the hip fracture can be serious. People who have had the surgery have a 5-20% greater risk of dying within the first year following that injury than do others in their age group. A large percentage of those who survive are unable to return to their previous level of activity, and many end up moving from self-care to a supervised living situation or nursing home. That's why getting early treatment andtaking steps to reduce bone loss are vital.
Building strong bones, especially before the age of 35, and maintaining a healthy lifestyle are the best ways of preventing osteoporosis. To build as muchbone mass as early as possible in life, and to help slow the rate of bone loss later in life:
Experts recommend 1,500 milligrams (mg) of calcium per day for adolescents, pregnant or breast-feeding women, older adults (over 65), and postmenopausal women not using hormone replacement therapy. All others should get 1,000 mg per day. Good sources of calcium are milk, cheese, yogurt, green leafy vegetables, tofu, shellfish, Brazil nuts, sardines, and almonds.
Those with calcium carbonate have the greatest amount of useful calcium. Supplements should be taken with meals and accompanied by six to eight glasses ofwater a day.
Vitamin D helps the body absorb calcium. People can get vitamin D from sunshine with a quick (15-20 minute) walk each day or from foods such as liver, fish oil, and vitamin-D fortified milk.
Smoking and heavy drinking reduce bone mass. To reduce risk, do not smoke, and limit alcoholic drinks to no more than two per day. An alcoholic drink is one-and-a-half ounces of hard liquor, 12 ounces of beer, or five ounces of wine.
Weight-bearing exercises--where bones and muscles work against gravity--are best. These include aerobics, dancing, jogging, stair climbing, tennis, walking, and lifting weights. Try to exercise three to four times per week for 20-30 minutes each time.