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.
DemographicsThe 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 devel-
oping 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 frac-
tures 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 per-
cent 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 osteo-
porosis among men of different races and ethnicities is
smaller than among women.
Causes and symptomsAlthough 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 (amenor-
rhea), 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 indi-
vidual’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.KEY TERMS
Anorexia nervosa—An eating disorder that
involves self-imposed starvation.
Menopause—The time when women are no longer
able to reproduce, the menstrual cycles stops, and
physical changes occur that are often related to a
decrease in the reproductive hormone estrogen.
Systemic lupus erythematosus (SLE)—A serious
autoimmune disease of connective tissue that
affects mainly women. It can cause joint pain,
rash, and inflammation of organs such as the
kidney.Osteoporosis