Osteoporosis, or porous bone, is a disease in which there is a loss of bone mass and destruction of bone tissue. This process causes weakening of the bones and makes them more likely to break. The bones most often affected are the hips, spine, and wrists.
Osteoporosis affects over 10 million Americans over the age of 50, with women four times more likely to develop osteoporosis than men. Another 34 million Americans over the age of 50 have low bone mass (ostopenia) and therefore have an increased risk for osteoporosis. Estrogen deficiency is one of the main causes of bone loss in women during and after menopause. Women may lose up to 20 percent of their bone mass in the five to seven years following menopause.
Although the exact medical cause for osteoporosis is unknown, a number of factors contribute to osteoporosis, including the following:
Bones become less dense and weaker with age.
Caucasian and Asian women are most at risk, although all races may develop the disease.
- Body weight
Obesity is associated with a higher bone mass, therefore people who weigh less and have less muscle are more at risk for developing osteoporosis.
- Lifestyle factors
The following lifestyle factors may increase a person's risk of osteoporosis:
- Physical inactivity
- Excessive alcohol use
- Dietary calcium and vitamin D deficiency
- Certain medications
- Family history of bone disease
In 2006, the North American Menopause Society (NAMS) reviewed and updated its guidelines on the diagnosis, prevention, and treatment of postmenopausal osteoporosis. Among its updated recommendations, NAMS suggests that women's lifestyle practices should be reviewed regularly by their physicians, and that practices that help to reduce the risk for osteoporosis should be encouraged. Also, NAMS recommends that a woman's risk for falls should be evaluated at least once a year after menopause has occurred. An additional recommendation is that a woman's height and weight should be measured annually, and she should be assessed for kyphoses - development of a rounded or humped spine- and back pain.
Osteoporosis is often called the "silent disease" because persons with osteoporosis may not develop any symptoms. Some may have pain in their bones and muscles, particularly in their back. Occasionally, a collapsed vertebra may cause severe pain, decrease in height, or deformity in the spine.
The symptoms of osteoporosis may resemble other bone disorders or medical problems. Always consult your physician for a diagnosis.
In addition to a complete personal and family medical history and physical examination, diagnostic procedures for osteoporosis may include the following:
- X-rays (skeletal) - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
- Bone density test (Also called bone densitometry.) - measurement of the mass of bone in relation to its volume to determine the risk of developing osteoporosis.
- Blood tests (to measure serum calcium and potassium levels)
- FRAX® score - a scor given to estimate the risk of a fracture within 10 years. The score uses the results of a bone densitometry test, as well as other individual tests
The effects of this disease can best be managed with early diagnosis and treatment.
Bone densitometry testing is primarily performed to identify persons with osteoporosis and osteopenia (decreased bone mass that has not yet reached the level of osteoporosis) so that the appropriate medical therapy and treatment can be implemented. Early treatment helps to prevent future bone fractures. It may also be recommended for persons who have already fractured a bone and are considered at risk for osteoporosis.
The bone densitometry test determines the bone mineral density (BMD). Your BMD is compared to two norms - healthy young adults (your T-score) and age-matched (your Z-score).
First, your BMD result is compared with the BMD results from healthy 25- to 35-year-old adults of your same sex and ethnicity. The standard deviation (SD) is the difference between your BMD and that of the healthy young adults. This result is your T-score. Positive T-scores indicate the bone is stronger than a health young adult; negative T-scores indicate the bone is weaker.
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According to the World Health Organization, osteoporosis is defined based on the following bone density levels:
- A T-score within 1 SD (+1 or -1) of the young adult mean indicates normal bone density.
- A T-score of 1 to 2.5 SD below the young adult mean (-1 to - 2.5 SD) indicates low bone mass.
- A T-score of 2.5 SD or more below the young adult mean (> - 2.5 SD) indicates the presence of osteoporosis.
In general, the risk for bone fracture doubles with every SD below normal. Thus, a person with a BMD of 1 SD below normal (T-score of -1) has twice the risk for bone fracture as a person with a normal BMD. A person with a T-score of -2 has four times the risk for bone fracture as a person with a normal BMD. When this information is known, people with a high risk for bone fracture can be treated with the goal of preventing future fractures.
Secondly, your BMD is compared to an age-matched norm. This is called your Z-score. Z-scores are calculated in the same way, but the comparisons are made to someone of your age, sex, race, height, and weight.
Specific treatment for osteoporosis will be determined by your physician based on:
- Your age, overall health, and medical history
- Extent of the disease
- Your tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
The goals of managing osteoporosis are to decrease pain, prevent fractures, and minimize further bone loss. Some of the methods used to treat osteoporosis are also the methods to help prevent it from developing, including the following:
- Maintain an appropriate body weight.
- Increase walking and other weight-bearing exercises.
- Minimize caffeine and alcohol consumption.
- Stop smoking.
- Maintain an adequate intake of calcium through diet and supplements. Vitamin D is also necessary because it facilitates the absorption of calcium.
- Prevent falls in the elderly to prevent fractures (i.e., install hand railings, or assistive devices in the bathroom, shower, etc.).
- Consult your physician regarding a medication regimen.
For postmenopausal osteoporosis in women, the US Food and Drug Administration (FDA) has approved the following medications to maintain bone health:
- Estrogen replacement therapy (ERT) and hormone replacement therapy (HRT)
ERT has proven to reduce bone loss, increase bone density, and reduce the risk of hip and spinal fractures in postmenopausal women. However, a woman considering ERT should consult her physician, as research conducted by the National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) found several important health risks associated with this therapy. For many women, the risks of ERT outweigh the benefits.
- Alendronate sodium (Fosamax®)
This medication, from a group of medications called bisphosphonates, reduces bone loss, increases bone density, and reduces the risk of fractures.
- Risedronate sodium (Actonel®)
This medication is also from the bisphosphonate family and has similar effects as alendronate.
- Ibandronate sodium (Boniva®)
This medication is a type of bisphosphonate that is taken once a month. It works by slowing the loss of bone, which may increase bone mass.
- Zoledronic acid (Reclast®)
This is an intravenous medication which can be given just once each year.
- Raloxifene (Evista®)
This medication is from a new group of medications called selective estrogen receptor modulators (SERMs) that help to prevent bone loss.
- Parathyroid hormone (Fortéo®)
This medication is a form of parathyroid hormone, teriparatide, and is approved to treat postmenopausal women and men who are at high risk for fractures. It helps form bone.
- Calcitonin (Fortical®, Miacalcin®)
This medication comes in both nasal spray and injected forms.
- Denosumab (Prolia®)
This medication is a RANK ligand inhibitor and is given every six months by injection.
An osteoporosis rehabilitation program is designed to meet the needs of the individual patient, depending upon the type and severity of the disease. Active involvement of the patient and family is vital to the success of the program.
The goal of rehabilitation is to help the patient to return to the highest level of function and independence possible, while improving the overall quality of life - physically, emotionally, and socially. The focus of rehabilitation is to decrease pain, help prevent fractures, and minimize further bone loss.
In order to help reach these goals, osteoporosis rehabilitation programs may include the following:
- Exercise programs and conditioning to increase weight bearing and physical fitness
- Pain management techniques
- Nutritional counseling to improve calcium and vitamin D intake and decrease caffeine and alcohol intake
- Use of assistive devices to improve safety at home patient and family education, especially prevention of falls
Osteoporosis rehabilitation programs can be conducted on an inpatient or outpatient basis. Many skilled professionals are part of the osteoporosis rehabilitation team, including any/all of the following:
- Orthopaedist/orthopaedic surgeon
- Rehabilitation nurse
- Physical therapist
- Occupational therapist
- Social worker
- Recreational therapist
- Vocational therapist