What is osteoporosis?
Osteoporosis is a disease that affects your bones. It means you have bones that are thin and brittle, with lots of holes inside them like a sponge. This makes them easy to break. Osteoporosis can lead to broken bones (fractures) in the hip, spine, and wrist. These fractures can be disabling and may make it hard for you to live on your own.
Osteoporosis affects millions of older adults. It usually strikes after age 60. It’s most common in women, but men can get it too.
What causes osteoporosis?
Osteoporosis is caused by a lack of bone strength or bone density. As you age, your bones get thinner naturally. But some things can make you more likely to have the severe bone thinning of osteoporosis. These things are called risk factors. Some risk factors you can change. Others you can’t change.
Risk factors you can’t change include:
* Your age. Your risk for osteoporosis goes up as you get older.
* Being a woman who has gone through menopause. After menopause, the body makes less estrogen. Estrogen protects the body from bone loss.
* Your family background. Osteoporosis tends to run in families.
* Having a slender body frame.
* Your race. People of European and Asian background are most likely to get osteoporosis.
Risk factors you can change include:
* Not getting enough weight-bearing exercise.
* Drinking too much alcohol.
* Not getting enough calcium and vitamin D in the things you eat or from supplements.
What are the symptoms?
Osteoporosis can be very far along before you notice it. Sometimes the first sign is a broken bone in your hip, spine, or wrist after a bump or fall.
As the disease gets worse, you may have other signs, such as pain in your back. You might notice that you are not as tall as you used to be and that you have a curved backbone.
How is osteoporosis diagnosed?
Your doctor will ask about your symptoms and do a physical exam. You may also have a test that measures your bone thickness (bone density test) and your risk for a fracture.
If the test finds that your bone thickness is less than normal but is not osteoporosis, you may have osteopenia, a less severe type of bone thinning.
It’s important to find and treat osteoporosis early to prevent bone fractures. The United States Preventive Services Task Force advises routine bone density testing for women age 65 and older. If you have a higher risk for fractures, it’s best to start getting the test at age 60.
How is it treated?
Treatment for osteoporosis includes medicine to reduce bone loss and to build bone thickness. Medicine can also give you relief from pain caused by fractures or other changes to your bones.
It’s important to take both calcium and vitamin D supplements along with any medicine you take for the disease. You need both of these supplements to build strong, healthy bones.
You can slow osteoporosis with new, healthy habits. If you smoke, quit. Get plenty of exercise. Walking, jogging, dancing, and lifting weights can make your bones stronger. Eat a healthy mix of foods that include calcium and vitamin D. Try dark green vegetables, yogurt, and milk (for calcium). Eat eggs, fatty fish, and fortified cereal (for vitamin D).
Making even small changes in how you eat and exercise, along with taking medicine, can help prevent a broken bone.
When you have osteoporosis, it’s important to protect yourself from falling. Reduce your risk of breaking a bone by making your home safer. Make sure there’s enough light in your home. Remove throw rugs and clutter that you may trip over. Put sturdy handrails on stairs.
Osteoporosis is a chronic disorder in which the mass of bones decreases and their internal structure degenerates to the point where bones become fragile and break easily.
Bone is living material. It is constantly broken down by cells called osteoclasts and built up again by cells called osteoblasts. This process is called bone remodeling, and it continues throughout an individual’s life. Normally, more bone is built up than is broken down from birth through adolescence. In the late teens or early twenties, people reach their peak bone mass—the most bone that they will ever have. For twenty or so years, bone gain and bone loss remain approximately balanced in healthy people with good nutrition. However, when women enter menopause, usually in their mid to late forties, for the first 5to 7 years bone loss occurs at a rate of 1–5% a year. Men
tend to lose less bone, and the loss often begins later in life. Osteoporosis occurs when bone loss continues and bones become so thin and their internal structure is so damaged that they break easily.
Bone remodeling occurs because bone is made primarily of calcium and phosphorous. Calcium is critically involved in muscle contraction, nerve impulse transmission, and many metabolic activities within cells. To remain healthy, the body must keep the level of free calcium ions (Ca 2+) within a very narrow concentration range. Besides providing a framework for the body, bone acts as a calcium “bank.” When excess calcium is present in the blood, osteoblasts deposit it into bones where it is stored. When too little calcium is present, osteoblasts dissolve calcium from bones and move it into the blood. This process is controlled mainly by parathyroid hormone (PTH) secreted by the parathyroid glands in the neck. As people age, various conditions cause them to take more calcium out of the “bone bank” than they deposit, and osteoporosis (which literally means porous bones) eventually develops. Osteoporosis is a silent disorder. It usually shows no symptoms until bones become so weak that they fracture from a seemingly minor bump of fall. All bones in the body may be affected by osteoporosis, but spinal vertebrae, the hip, and the wrist and forearm are the bones most often broken.
The National Osteoporosis Foundation estimates that 10 million people in the United States over age 55 have osteoporosis, and another 34 million have lost enough bone mass to put them at high risk for developing the disorder. The National Institutes of Health estimate that 25 million people in the United States have osteoporosis. Since people rarely seek treatment until they have a bone fracture, accurate estimates are difficult to obtain. However, about 1.5 million fractures are attributed to osteoporosis in the United States each year. Internationally, in Europe 1 of every 8 people over age 50 will have a spinal fracture, suggesting a high rate of osteoporosis.
Osteoporosis is a disorder of older individuals. It rarely develops before age 50. and the likelihood of developing it increases steadily with age. Eighty percent of the people who have osteoporosis are women, but there is a fair amount of variation among the rate in women of different ethnic groups. White women, especially those of northern European ancestry, are at highest risk of developing osteoporosis. Their rate is twice as high as Hispanic women and four times as high as black women. White men also are most likely to be affected, but the differences in the rate of osteoporosis among men of different races and ethnicities is smaller than among women.
Causes and symptoms
Although the immediate cause of osteoporosis is loss of bone, there are many risk factors that increase the change of developing this condition. Age, race, gender, and heredity play a role in the development of osteoporosis, but other the risk factors are related to lifestyle. These include:
* cigarette smoking. Smoking causes the liver to destroy estrogen at a faster than normal rate .
* heavy alcohol consumption. Alcohol can interfere with calcium absorption.
* lack of exercise. Weight bearing exercises help increase bone mass.
* too much strenuous exercise in women. Extreme exercise causes menstrual cycles to stop (amenorrhea), reducing estrogen levels.
* Poor diet. Vitamin D and calcium are both necessary to build strong bones.
Medical conditions and treatments can also cause osteoporosis. These include:
* conditions that cause low testosterone levels in men (e.g. hypogonadism)
* cancer or treatment with certain chemotherapy drugs (e.g. cyclosporine A).
* early hysterectomy or removal of the ovaries. This reduces the level of estrogen in the body.
* use of anticonvulsant drugs (e.g. phenytoin, carba-mazepin). These cause vitamin D deficiency and reduce the amount of calcium absorbed from the intestine.
* long-term use of corticosteroids drugs (e.g. cortisone, prendisone) to treat conditions such as systemic lupus erythematosus (SLE) or rheumatoid arthritis. These drugs directly inhibit bone formation.
* Certain hormonal disorders such as Cushing syndrome where the body makes too many corticosteroids
* spinal cord injury that results in paralysis or any other medical condition that severely limits the individual’s physical activity
Osteoporosis is a disorder that shows few obvious symptoms. Elderly individuals may begin to lose height and develop a curved upper back and what is sometimes called a dowagers hump. For most people, signs of osteoporosis only become apparent when they either fracture a bone or have a bone mineral density (BMD) test done.
Diagnosis begins with a medical history to determine whether what risk factors the individual has. The physician may order blood and urine tests to rule out other disorders. The definitive test for osteoporosis is a bone mineral density (BMD) test. The most commonly used BMD is called a dual-energy x-ray absorptiometry (DXA)test. This test measures the density of bone in the hip and spine. It is similar to an x ray, only with less exposure to radiation, and it is painless. Results are given as a T-score, with negative numbers indicating low bone mass. Occasionally the physician may order a bone scan. A bone scan checks for bone inflammation, fractures, bone cancer, and other abnormalities, but it does not measure bone density.
Osteoporosis cannot be cured but it can be treated with exercise (see Therapy), diet, and sometimes with medication. There are several types of prescription medications approved by the United States Food and Drug Administration for the treatment of osteoporosis.
* Antiresorptive medications slow or prevent bone from being broken down. These include alendronate sodium (Fosamax), ibandronate sodium (Boniva), etidronate (Didronel), and risedronate sodium (Actonel). If drug therapy is used, these medication are often the first choice.
* In women, estrogen therapy and hormone replacement therapy drugs increase the level of estrogen in the body and improve bone health. Because of side effects such as the increase in breast cancer, heart attacks, and stroke, these drugs are used less frequently. Most often they are used to treat other symptoms of menopause rather than specifically to treat osteoporosis.
* Selective estrogen receptor modulators (SERMs) such as raloxifene (Evista). These drugs are being developed to replace estrogen and hormone therapy drugs. They act on estrogen receptors in bone in a way that prevents the bone from being broken down.
* Parathyroid hormone stimulates the formation of new bone by activating more new osteoblasts. It is marketed as teriparatide (Fortéo)
* Calcitonin (Miacalcin, Calcimar, Cibacalcin) is a hormone that slows bone breakdown by inhibiting osteoclast activity.
Calcium and vitamin D are both essential to building and maintaining strong bones. Dairy products are a good source of these nutrients. Calcium supplements are recommended for many women who have difficulty getting enough calcium in their diet. Recommended dietary allowances (RDAs)and lists of foods that are high in calcium and vitamin D can be found in their individual entries. Fluoride also is needed to develop healthy bones and teeth.
People with the eating disorder anorexia nervosa are at especially high risk of developing osteoporosis later in life because they have poor, unbalanced diets. The menstrual cycle in girls with anorexia is often delayed in starting or if it has started, stops. In addition, people with anorexia almost never get enough calcium to build strong bones during adolescence and they make unusually larger amounts of cortisol, a corticosteroid made by the adrenal gland that causes bone loss. Although the effect of this eating disorder on bones will not be seen until the individual is older, failure to build strong, dense bones during the teen years substantially increases the risk of osteoporosis later.
Physical therapy involving weight-bearing exercises an help individuals of any age, even those who are frail or have chronic illnesses slow bone loss and regain muscle mass. Physical therapy exercises that emphasize improving strength, flexibility, coordination, and balance also decrease the risk of falls and fractures in individuals who have osteoporosis.
Osteoporosis cannot be cured but preventive behaviors and treatment can slow its progression. Falls that result in hip and spine fractures present the greatest risk of complications. Almost one-fourth of people over age 50 who have hip fractures die within one year. Although women have two to three times more hip fractures than men, men with hip fractures die twice as often as women. One study found that six months after a hip fracture, only about 15% of individuals could walk across a room unaided. Many require long-term care. About 20% end up in nursing homes. Quality of life is greatly affected by osteoporosis.
Prevention should begin in childhood and the teenage years with healthy diet and plenty of physical activity to build strong bones. The higher the bone mass density in early adulthood, the greater the chance of avoiding or delaying the effects of osteoporosis.
Individuals need to get the RDA for calcium and vitamin D beginning in childhood and continuing through old age. Exercise at any age is also beneficial in slowing osteoporosis. A BMD test should be done every two years in older individuals. Medicare will usually pay for a BMD test every two years. Signs of osteoporosis should be treated as soon as they appear.