What
is osteoporosis?
Osteoporosis, which means "porous bones," is a condition
of the skeleton in which the amount of calcium present in the bones
slowly decreases to the point where the bones become less dense
and more prone to fracture. Contrary to popular belief, it is not
just a disorder of the elderly woman. It can occur in the college-aged
population. People with eating disorders, high performance athletes
or patients on certain medications may be at the greatest risk.
Even if you have no present high risk factors, building strong bones
today may prevent osteoporosis from occurring in the future.
How
does it occur?
Our skeleton provides structural support for our muscles and organs.
In addition, it serves as a storage depot for 99% of the body's
calcium. The remaining 1% is free to circulate in the blood and
is essential for crucial body functions including muscle contraction,
nerve function and blood clotting.
Bone
is not a lifeless structure. It is a living, growing tissue. In
order to meet our body's needs it is constantly being broken down
and reformed again in a process called remodeling. The breakdown
is done by cells known as osteoclasts which dig holes into the bone,
releasing the small amounts of calcium into the bloodstream that
are necessary for other vital functions. Cells called osteoblasts
then rebuild the skeleton, first by filling in the holes with collagen
and then by laying down crystals of calcium and phosphorus.
From
childhood to adulthood, bone is made faster than it is broken down
and bones become larger and denser. Peak bone mass occurs by the
mid 20's. The remodeling process, in which bone is broken down faster
than it is made, begins to reverse as early as age 35 and results
in precipitous bone loss after menopause. It is crucial that young
adults "bank" enough calcium in their bones to draw on
later in life to prevent osteoporosis. A person who has exceptionally
dense bones to begin with will probably never lose enough calcium
to reach the point where osteoporosis occurs. However, a person
who has low bone density could easily develop osteoporosis despite
losing only a relatively small amount of calcium.
Many
factors affect the remodeling process. A deficiency of the hormone
estrogen appears to increase bone loss. This occurs naturally after
menopause but can also occur with surgical removal of the ovaries.
Intense exercise such as marathon running affects hormonal levels
and may lead to osteoporosis. Severe underweight and undernutrition
problems that occur in patients with eating disorders can lead to
hormonal deficiencies which cause amenorrhea (absence of menstrual
periods) and severe osteoporosis.
What
are the signs and symptoms of osteoporosis?
Early osteoporosis may have no symptoms. Symptoms occurring LATE
in the disease include:
Fractures
of the vertebrae, wrists or hips following very minor trauma
Low
back pain
Neck
pain
Bone
pain or tenderness
Loss
of height over time (may be as much as 6 inches)
Stooped
posture ("dowager's hump")
What
factors increase your risk of developing osteoporosis?
For women:
Being
female (80% of osteoporosis occurs in women)
Increasing
age: after 65 about 30% of women have osteoporosis
Being
postmenopausal, either due to natural or surgical menopause (decreased
estrogen)
Estrogen
deficiency due to abnormal absence of menstruation. This can occur
in persons with eating disorders or high performance athletes.
In fact, over half of anorexics have osteoporosis with bones resembling
those of women in their 70s or 80s.
Ethnic
heritage - Caucasian and Asian women are at highest risk. Risk
is lower for African American and Latino women.
Thin,
slight body frame
Lifestyles
that increase the risk of osteoporosis include smoking, alcohol
use, high caffeine use, lack of exercise and low intake of calcium
and vitamin D.
Certain
medications may increase risk including steroids, excessive thyroid
medications, anticoagulants, antiepileptic drugs and immunosuppressants.
Certain
metabolic diseases can cause secondary osteoporosis.
For Men:
Men start with higher bone density and lose calcium at a slower
rate than women, which is why their risk is lower. However, men
can develop osteoporosis. In men, a testosterone deficiency may
contribute. Many of the risk factors, such as ethnic heritage, body
frame, lifestyle and medication risks listed above, are the same
as for women. However, men typically develop osteoporosis at a later
age than women (after 60).
What
tests can be done to confirm the diagnosis of osteoporosis?
Osteoporosis can be confirmed by bone-density testing. This is usually
suggested for women over 65, postmenopausal women with risk factors
of osteoporosis or who have had a fracture. Young women who have
risk factors for osteoporosis such as having an eating disorder
or absence of menstruation from over-exercising should also consider
being tested.
Currently,
the most accurate technique for determining bone density is dual
x-ray absorpitometry (DEXA). The measurements are made by detecting
the extent to which bones absorb photons that are generated by very
low-level x-rays. This test is painless and quick. When the bone
mineral density is 2.5 standard deviations below the average for
young adults, a diagnosis of osteoporosis is made. If the bone mineral
density is between 1 and 2.5 standard deviations below the norm,
a patient is diagnosed with osteopoenia, a slightly less advanced
form of weakened bones. One standard deviation below the norm in
a measurement of hipbone density is equivalent to adding 14 years
to a person's age-related risk of fracture.
How
is osteoporosis treated?
Treatment cannot eliminate osteoporosis, but medicines may be able
to slow down the loss of bone. Most of the medicines available today
are primarily aimed at treating osteoporosis in the postmenopausal
woman. Studies are presently underway investigating therapies for
the younger patient with osteoporosis. Oral contraceptives have
not been found to be effective in treating anorexics with osteoporosis.
Investigational studies are looking at insulin-like growth factor-1,
testosterone, and a postmenopausal osteoporosis medication as possible
therapeutic agents for young women.
Increasing
calcium intake to 1500 mg per day, increasing vitamin D to 800 IU
per day and maintaining normal weight and exercise patterns to restore
hormonal balance may be helpful in preventing further bone loss.
