What is Osteoporosis and Who is at Risk?
Osteoporosis is a disease in which bones become weak and brittle. If left unchecked, osteoporosis can progress painlessly until a bone breaks (fracture). Any bone can be affected, but of special concern are fractures of the hips, spine, and wrists. If diagnosed early, progression of osteoporosis can be slowed and complications prevented.
Throughout life, old bone is removed and new bone is added to the skeleton. During childhood and adolescence, new bone is added faster than old bone is removed. As a result, bones become heavier, larger, and denser. Peak bone mass is reached around age 30. From that point on, more bone is lost than is replaced, usually at a slow rate. When women reach menopause and their estrogen level drops, bone loss begins to more rapidly exceed bone replacement. If not treated, excessive bone losses may lead to osteoporosis. Osteoporosis is more likely to occur if optimal bone mass was not achieved during the bone-building years.
Bone density also plays a role in bone health. Bone density is determined in part by the amount of calcium, phosphorus, and other minerals contained within the framework of the bone. As the mineral content of a bone (especially calcium) decreases, the bone becomes weaker. Getting enough calcium and vitamin D and exercising regularly can help ensure that bones stay strong throughout life.
An estimated 10 million Americans have osteoporosis; 80% are women. An additional 18 million people have low bone mass, which puts them at risk of osteoporosis. In all, osteoporosis affects nearly 40% of women over the age of 50.
It is possible to develop osteoporosis with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing osteoporosis. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.
Risk Factors for Women
Women are at greater risk of developing osteoporosis than men. This is because they have less bone tissue than men and have a sudden drop in hormones-especially estrogen-at menopause.
Estrogen deficiencies occur as a result of:
- Menopause: Natural or surgical menopause increases your risk of osteoporosis. The risk of fracture increases significantly five years after menopause. Though initial fractures may be in the wrist or spine, these strongly predict the later development of severe osteoporosis and hip fracture.
- Amenorrhea (cessation of menstruation before menopause): Your risk of osteoporosis increases if you miss menstrual periods for three months or longer. Amenorrhea may occur with eating disorders, such as anorexia nervosa and bulimia, or with excessive or intensive exercise, such as long distance running.
These are some other risk factors may increase a woman's risk of developing osteoporosis:
- Family history of osteoporosis
- Gastrointestinal malabsorption
- Having another endocrine disorder (eg, thyroid disorder, diabetes)
Risk Factors for Men
Men have a higher bone density and lose calcium at a slower rate than women. However, after age 50, bone loss gradually increases. In men, deficiencies of testosterone and, to a much minor extent, estrogen play a role in the development of osteoporosis. This may be related to:
- Advanced age
- Certain conditions that reduce testosterone levels (eg, mumps, treatment for prostate cancer)
- Hypogonadism (a severe deficiency in the male sex hormone)
Risk Factors in Both Sexes
- Dietary factors. Your risk of developing osteoporosis increases if you have a restrictive diet (eg, not getting enough calcium or vitamin D). An excess of phosphorous in your diet may increase your risk if your calcium and/or vitamin D intakes are low. Excessive use of alcohol, coffee, or tea may also increase your risk of osteoporosis.
- Lack of exercise. Regular exercise , especially weight-bearing and resistance exercise, helps strengthen bones. Therefore, if you do not exercise on a regular basis, you may increase your risk of developing osteoporosis. Individuals who do not exercise regularly also tend to have weaker muscles and poorer balance, which can lead to falls and fractures.
- Smoking. Smoking impairs bone, muscle, and joint health. If you smoke, you have a higher risk of developing osteoporosis.
- Bone structure and body weight. Small-boned women and underweight people of both sexes have an increased risk of osteoporosis. Individuals who are short, thin, and have narrow hips are at increased risk of low bone density and fracture.
- Lack of sunlight. The effect of sun on the skin is a primary source of vitamin D, which aids bone formation. If you get very little sun exposure and have a low dietary intake of vitamin D, you may be at increased risk of osteoporosis.
- Ethnic background. Caucasian, Asian, and Hispanic women are more likely to develop osteoporosis than those of other ethnic groups. Though most ethnic studies have focused on women, it is believed that men in these ethnic groups carry a parallel but lower risk.
- Medications. The long-term use of certain medicines increases your risk of osteoporosis. Examples include corticosteroids, medicines to suppress the immune system, chemotherapy, thyroid medicines, antidepressants (eg, tricyclic antidepressants, selective serotonin reuptake inhibitors), antiseizure medicines, medicines containing aluminum (eg, certain antacids), long-term heparin therapy and glitazones (diabetes medicine). Talk to your doctor before stopping or reducing your medicine.
- Chronic diseases. Certain chronic diseases may increase your risk for developing osteoporosis such as cardiovascular disease, asthma, liver disease (eg, cirrhosis), kidney disease, rheumatoid arthritis, type 2 diabetes, hyperthyroidism, hyperparathyroidism, cushing's syndrome, sarcoidosis, scurvy (vitamin C deficiency), gastrointestinal disorders (especially those causing malabsorption), eating disorder, alcoholism, depression (possibly be due to higher levels of the stress hormone cortisol, which may contribute to loss of bone density), inherited disorders (eg, Marfan syndrome, Ehler-Danlos syndrome, porphyria), cancer (eg, lymphoma, leukemia, myeloma), treatment for cancer (eg, chemotherapy, radiation therapy), organ transplant and crohn's disease.
- Diseases during childhood. If you had certain conditions during childhood, you may be at an increased risk for developing osteoporosis later in life. Examples of these conditions include premature birth, anorexia nervosa, asthma or other diseases that are treated with corticosteroids, disorders that cause malabsorption (eg, cystic fibrosis, inflammatory bowel disease, celiac disease) and conditions that cause low hormone levels (eg, delayed puberty, delayed onset of periods in girls, infrequent or no periods in girls).
Osteoporosis is often referred to as a silent disease. The associated bone loss usually occurs without symptoms. Since many people mistakenly believe that all medical conditions cause symptoms. As a result, they do not see a doctor until the condition is far advanced.
In the early stages of osteoporosis, there is usually no pain or other symptoms. Once the bones have been weakened, you may have the following symptoms:
- Collapsed vertebra, which may initially be felt or seen in the form of:
- Severe back pain
- Loss of height over time, with stooped posture (kyphosis). With normal aging, everyone has some loss of height. However, a loss of one inch or more is significant and may indicate osteoporosis.
- Fracture of a bone, such as the wrist or hip, due to the bones becoming over-brittle. This is sometimes the first symptom of osteoporosis.
Osteoporosis can be detected with bone density testing. First, the doctor will ask about your symptoms and medical history and perform a physical exam. If the doctor suspects you may have osteoporosis or you are at risk for osteoporosis, you may have one or more of the following tests:
Bone Mineral Density Tests
Bone mineral density (BMD) tests are painless, noninvasive tests that measure your bone mass. With a BMD test, your bone mass is measured and then compared to that of either (1) a healthy 30-year-old adult (T score), or (2) the expected bone mass of someone your age (Z score). Because low BMD is common among older adults, comparison to peers your age can be misleading. The results of a BMD test will indicate whether you have normal bone density, low bone density (osteopenia), or full-blown osteoporosis. These test results, coupled with assessment of your risk factors for osteoporosis, will help you and your doctor decide which prevention or treatment options are right for you.
- Blood and urine tests-These tests check calcium levels and other substances created when bone is formed or broken down. These are called biochemical markers of bone turnover. Results indicate whether the process of bone breakdown in your body is occurring at a normal or at an excess rate.
- Bone biopsy-done in certain cases to check for other causes of bone disease
The treatment and management of osteoporosis involves lifestyle changes and medications. Although osteoporosis is highly preventable, it cannot be cured. Lost bone cannot be replaced. Instead, treatment focuses on reducing the incidence of fractures and slowing bone loss.
Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted March 2011