When Winchester gynecologist Robert Shirley does an ultrasound
bone scan
of a patient's heel, the news he delivers is often less than
comforting.
Based on the heel scan, which measures
bone density in the foot, Dr.
Shirley diagnoses 1 in 3 of his older patients
with either osteoporosis or
osteopenia, the bone-thinning disease that is
common in aging women and
also affects some older men.
``It's a very helpful tool to make them realize that
osteoporosis is
real, and they need to think about it,'' said Shirley.
Certainly, few women will fail to take notice when
they hear they have
a disease that may lead to brittle bones, a hunched back
or ``Dowager's
hump,'' and painful, disabling fractures. As frightening as
the diagnosis
sounds, however, it does not always lead to serious fractures
_ the most
severe of which is hip fracture _ and the bone scan itself
cannot
accurately
predict who will get hip fractures, or even fully
measure bone strength.
Still, osteoporosis is
now defined by bone density, even though
density only accounts for about 70
percent of bone strength. Other factors
_ such as the actual shape,
structure and size of a bone, and the presence of
tiny cracks know as
``microdamage'' _ seem to factor in as well.
But these things are not measured by bone scans. And, when it comes
to hip
fractures and the elderly, a person's risk of falling seems to play as
much
of a role in fracture risk as does bone density.
So, when a
group of scientists convened by the National Institutes of
Health met for
three days in late March to review the most current data on
the diagnosis
and treatment of osteoporosis, they declined to endorse the
bone scan as a
screening test for osteoporosis. In its March 29
consensus statement, the
panel noted that the risks for osteoporosis _ as reflected
by low bone
density _ and the risks for fracture, overlap but are not
identical.
In addition, the panel expressed concern that
different bone scanning
devices and techniques produce conflicting results.
A committee of scientists is
working on a plan to standardize the tests, but
right now, an ultrasound bone scan
of the heel might indicate osteoporosis,
while an x-ray scan of the spine may not. And
even though bone loss can
accelerate at menopause, tests in women under the age
of 60 are particularly
weak at predicting hip fractures.
``There are other things
outside of bone density that we may want to
measure to better improve our
prediction of fracture risk,'' Mary Bouxsein,
an instructor in the
Orthopedic Biomechanics Laboratory at Beth Israel
Deaconess Medical Center
told the panel.
This is in stark contrast to
what many doctors and advocacy groups
say about bone scans and osteoporosis.
Many see the disease as a silent
epidemic that goes undiagnosed in
millions of women. The National
Osteoporosis Foundation cites an
alarming list of statistics to drive that
point home: 28 million people
either have the disease or are at risk, and
half of all women will suffer a
fracture of the spine, hip or wrist
during their lifetime.
The group recommends bone scan screening for all women over
65, has lobbied
Medicare to cover the test, and is now pushing for
mandatory private
insurance coverage.
Bone scans are not
perfect, but they are the best tool available to
identify women with the
disease, said Conrad Johnston, director of the
Bone Studies Laboratory at
Indiana University, who is the current president of
the National
Osteoporosis Foundation. ``Everybody who has high cholesterol
doesn't have a
heart attack, and everyone who has low bone mass doesn't
have a
fracture. But for many women, he said, ``low bone density is the
single
best predictor of who will fracture.''
So should women just ignore this? The
pharmaceutical industry
certainly isn't. The makers of bone building drugs
are active in promoting
bone scans. Merck, which makes Fosamax, recently ran
ads in magazines like
Good Housekeeping and Parade encouraging healthy women
to seek testing.
Warning that undiagnosed osteoporosis can lead to broken
bones or the
disfiguring Dowager's hump, the ad equates the simple, painless
bone
density test with mammography to detect breast cancer.
Osteoporosis is
serious business for many who have it. According
to the National
Osteoporosis Foundation, the disease causes 1.5 million
fractures annually,
about half of them in the spine. Spinal fractures can
cause a range of
symptoms; some people may feel nothing at all, others may
have back pain,
and yet others may develop the Dowager's hump.
The
scientific data on the incidence and severity of spinal fractures
is
incomplete. But, all agree that the hip fracture, which strikes about
300,000 people per year in their 70s and 80s, can be a devastating and
sometimes deadly event. About 30 percent of older people who fall and
break a hip end up in a nursing home.
Bone
density contributes to hip fractures, but so does a long list of
other
factors including age, low body weight, smoking, mobility, exercise
habits,
and poor eyesight, which can make someone more vulnerable to falls,
says Dr.
Arminee Kazanjian, the director of the British Columbia Office of
Health
Technology Assessment.
After reviewing years
of research into bone mass and fracture, her
agency released on of the most
scathing critiques on the use of bone scans.
It concluded that as many as 70
percent of the women who eventually break a
hip will not be diagnosed at
menopause with osteoporosis, if that diagnosis
is based on a bone scan
alone. And, only half of the 30 percent of women
identified as having
osteoporosis or osteopenia will go on to have a
fracture.
``The important health outcome is bone fracture,'' said Kazanjian.
``Bone mineral density is a minor factor. Any other combination of
factors
is much more important.'' Rather than rely on the bone scans
alone to
diagnose osteoporosis, Kazanjiam and others
suggest that doctors focus
on the other factors that contribute to fracture
risk.
For example, a woman with low bone density, but who
doesn't smoke
(which contributes to thinning bones) and has good eyesight,
may be less likely to
break a hip than a woman with high bone density who
uses a walker and has a
family history of fractures, she said.
Amy Allina of the National Women's Health
Network, a Washington,
D.C.-based advocacy group, says that women who are
told they don't have
osteoporosis based on a bone scan alone may not take
steps to prevent the
falls that cause hip fractures, even though they may be
at risk. And those
whose bone scans indicate that they have osteoporosis may
spend years on
medication, even though they may never have broken a bone.
That's a problem, Allina said, because the
treatments for osteoporosis themselves
come with risks. Hormone replacement
therapy, which millions of women take
to both treat and prevent
osteoporosis, can increase a woman's odds of
developing breast cancer. And
Fosamax, a non-hormone drug that builds bone,
irritates the throat and its
long-term effects are unknown.
A 1993 decision by a
World Health Organization panel set the stage for the bone
scan to
inadvertently become a routine diagnostic test for osteoporosis. The
panel
established a scale _ based on the average bone density of a premenopausal
woman _ that allows doctors to measure bone loss, diagnose osteoporosis,
and establish fracture risk.
The average 55-year-old
woman has a 15 percent chance of breaking her
hip someday. If her bone
density is 1 point below the WHO average, she is
defined as having
osteopenia, a level of bone thinning that increases the
lifetime risk of hip
fracture by 20 to 45 percent. Osteoporosis is
diagnosed when bone density
falls 2.5 points below the WHO average. This, by some
measures, raises the
risk of hip fracture to greater than 45 percent.
Brigham and Women's Hospital in
Boston recently produced a detailed
set of osteoporosis diagnosis and
treatment guidelines for its patients and
doctors. The guidelines don't
endorse bone scans to be used as screening
tools alone, but they advise
doctors to recommend bone scans to all women
over the age of 65.
Dr. Robert Barbieri, chairman of the
Department of Obstetrics and
Gynecology at Brigham and Women's, sees the
bone scan as a useful tool but
he emphasized that a diagnosis of
osteoporosis should not be based on the test
alone. He says he is confident
that doctors are considering other factors
when assessing a patient's bone
strength and risk of a fracture.
``They use history
and physical exams and laboratory tests in an integrative way
and pull them
all together,'' he said.
But Mark
Hefland, a researcher at the Oregon Health Sciences University, told the NIH
pane that doctors are relying too heavily on bone scans, even though many of
them
admit that they don't understand how bone scan scores relate to
fracture risk.
``However we may like it, this
is how diagnosis is occurring in everyday
practice,'' said Hefland, the
director of the school's Evidence-Based
Practice Center.
Dr. Shirley of Winchester says he relies on bone scans to
diagnose
osteoporosis, but said that he also spends a lot of time with
patients
talking about fracture risk and alternatives to drug therapy like
increasing weight-bearing exercise and boosting calcium intake.
But according to Diane Saparoff, who runs a monthly
support group for
women with osteoporosis at the Jenks Senior Center in
Winchester, Dr.
Shirley's approach differs greatly from that of other
doctors. ``Many of
the doctors order these tests but there is no follow
up,'' she said. The
doctors often don't explain the test scores or help
women come up with a fracture
prevention plan, she said. ``They just throw
Fosamax at them.''
Dr. Johnston of the
National Osteoporosis Foundation acknowledges
that some doctors may be
relying too much on bone scans to diagnose
osteoporosis.
``I think
that's probably happening but it shouldn't be,'' he said. ``This
is a
reasonably new area. Bone mineral measurements have only been around
for
about 10 years. Its takes a while for people to get up speed.''
Sidebar
Report lists ways to avoid injuries
A recent report from the National Institutes of Health offers advice
on
how to build and maintain strong bones:
*Get adequate calcium
and vitamin D both early in life and throughout adulthood.
* Engage
in regular exercise; it contributes to the development of peak
bone mass and
may reduce the risk of falls in older individuals.
*As needed,
use drugs that enhance bone mass; medications have been been
shown to reduce
the risk of osteoporotic fractures.
In addition to
regular exercise, there are several steps seniors can
take to avoid falls,
according to the National Center for Injury Prevention
and Control:
* Use non-slip rugs and bath mats. Put grab
bars in the bathroom
and handrails on the stairs.
* Ask your doctor to review medicines that may
cause drowsiness or
confusion when combined with others you may be taking.
*Stay current with eye exams.
--Tinker Ready
This story ran on page D01 of the Boston Globe on 4/25/2000.
© Copyright 2000 Globe Newspaper Company.