Osteoporosis
What is it?
Osteoporosis means weakened or porous bones. Bones incorporate
calcium to maintain strength and hardness. When you eat food containing
this mineral, it is absorbed into the bloodstream to be distributed
throughout the body; calcium in excess of metabolic needs is deposited
in the bones. When calcium intakes are deficient, calcium leaches from
the bone to supply physiological processes. If calcium intake remains
insufficient over a long period of time, bones lose more and more
calcium and eventually become porous and weak or osteoporotic. Bones
weakened by osteoporosis are thin and brittle and highly susceptible to
fracture.
Osteoporosis frequently affects the spinal column. As bone porosity
increases, the vertebrae can collapse (in a compression fracture) and
cause sudden and severe back pain. Gradual collapse contributes to the
loss of height that comes with age. Wrist and hip fractures are also
common to people suffering from osteoporosis.
There is no cure for osteoporosis, but it can be controlled. Most
people who have osteoporosis fare well once they get treatment. The
medicines available now build bone, protect against bone loss, and halt
the progress of this disease.
Who gets it and what are its causes?
Osteoporosis occurs most often in older people and in women after
menopause. It affects nearly half of all those, men and women, over the
age of 75. Women, however, are five times more likely than men to
develop the disease. Women have smaller, thinner bones then men, and
they lose bone mass more rapidly after menopause (usually around age
50), when they stop producing a bone-protecting hormone called estrogen.
Five to seven years after menopause, women can lose up to about 20% of
their bone mass. By age 65 though, men and women lose bone mass at the
same rate. As an increasing number of men reach an older age, there’s
more awareness that osteoporosis is an important health issue for them
as well.
Factors contributing to the development of osteoporosis could include
the following:
- Vitamin D Deficiency-lack of Vitamin D decreases the bones’
absorption of calcium.
- Estrogen Deficiency-without estrogen, bones demineralization
accelerates.
- Inactivity-weight bearing exercise is necessary to stimulate bone
strengthening. A lack of exercise may contribute to a loss of bone
calcium.
- Gender-women are at a greater risk than men.
- Heredity-if the disease runs in your family—mother or
grandmother.
- 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 with small bones and those who are thin are more
liable to have osteoporosis.
- Early menopause-women that stop menstruating early because of
heredity, surgery or lots of 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, or don’t get enough
exercise have an increased chance of getting osteoporosis.
- Diet-people who don’t get enough calcium or protein may be more
likely to have osteoporosis. People who constantly diet are more
prone to the disease.
Diagnosis
Certain types of doctors may have more training and experience than
others in diagnosing and treating people with osteoporosis. These
include a geriatrician, who specializes in treating the aged; an
endocrinologist, who specializes in treating diseases of the body's
endocrine system (glands and hormones); and an orthopedic surgeon, who
treats fractures, such as those caused by 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. It
can also show how far the disease has progressed.
Several diagnostic tools are available to measure the density of a
bone. The ordinary x-ray is one, though it's the least accurate for
early detection of osteoporosis, because it doesn't reveal bone loss
until the disease is advanced and most of the damage has already been
done. Two other tools that are more likely to catch osteoporosis at an
early stage are computed tomography scans (CT scans) and machines called
densitometers, which are designed specifically to measure bone density.
The CT scan, which takes a large number of x-rays of the same spot
from different angles, is an accurate test, but uses higher levels of
radiation than other methods. The most accurate and advanced of the
densitometers uses a technique called DEXA (dual energy x-ray
absorptiometry). With the DEXA scan, a double x-ray beam takes pictures
of the spine, hip, or entire body. It takes about 20 minutes to do, is
painless, and exposes the patient to only a small amount of
radiation--about one-fiftieth that of a chest x ray.
Doctors don't routinely recommend the test, partly because access to
densitometers is still not widely available. People should talk to their
doctors about their risk factors for osteoporosis and if, and when, they
should get the test. Ideally, women should have bone density measured at
menopause, and periodically afterward, depending on the condition of
their bones. Men should be tested around age 65. Men and women with
additional risk factors, such as those who take certain medications, may
need to be tested earlier.
Treatment
There are a number of good treatments for primary osteoporosis, most
of them medications. The FDA (Food and Drug Administration) has approved
two new medications, alendronate and calcitonin (in nose spray form).
They provide people who have osteoporosis with a variety of choices for
treatment. For people with secondary osteoporosis, treatment may focus
on curing the underlying disease.
For most women who've gone through menopause, the best treatment for
osteoporosis is hormone replacement therapy (HRT), also called estrogen
replacement therapy. Many women participate in HRT when they undergo
menopause, to alleviate symptoms such as hot flashes, but hormones have
other important roles as well. They protect women against heart disease,
the number one killer of women in the United States, and they help to
relieve and prevent osteoporosis. 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. Other studies reveal the risk is due to increasing age.
(Breast cancer tends to occur more often as women age.) Whether or not a
woman takes hormones is a decision she should make carefully with her
doctor. Women should talk to their doctors about personal risks for
osteoporosis, as well as their risks for heart disease and breast
cancer. Most women take estrogen along with a synthetic form of
progesterone, another female hormone. The combination helps protect
against cancer of the uterus.
For people who can't or won't take estrogen, two other medications
can be good choices. These are alendronate and calcitonin. Alendronate
and calcitonin both stop bone loss, help build bone, and decrease
fracture risk by as much as 50%. Alendronate (sold under the name
Fosamax) is the first nonhormonal medication for osteoporosis ever
approved by the FDA. It attaches itself to bone that's been targeted by
bone-eating osteoclasts. It protects the bone from these cells.
Osteoclasts help your body break down old bone tissue.
Calcitonin is a hormone that's been used as an injection for many
years. A new version is on the market as a nasal spray. It too slows
down bone-eating osteoclasts.
Side effects of these drugs are minimal, but calcitonin builds bone
by only 1.5% a year, which may not be enough for some women to recover
the bone they lose. Fosamax has proven safe in very large, multi-year
studies, but not much is known about the effects of its long-term use.
That's why estrogen medications may still be the medicine of choice for
a few years, as researchers continue to study other drugs. Several
medications under study include other biphosphonates that slow bone
breakdown (like alendronate), sodium fluoride, vitamin D metabolites,
and selective estrogen receptor modulators. Some of these treatments are
already being used in other countries, but have not yet been approved by
the FDA for use in the United States.
What is the surgical treatment?
Unfortunately, much of the treatment for osteoporosis is for
fractures that result from advanced stages of the disease. For
complicated fractures, such as broken hips, hospitalization and a
surgical procedure are required. In hip replacement surgery, the broken
hip is removed and replaced with a new hip made of plastic, or metal and
plastic. Though the surgery itself is usually successful, complications
of the hip fracture can be serious. Those individuals 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 and taking steps to reduce bone
loss are vital.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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