As the popular childhood song
goes, "the toe bone's connected to the foot bone," and
so on, but it neglects to mention where the joints fit
into the picture. According to research published in the
December issue of the Annals of the Rheumatic Diseases,
this may be a grave omission. The report links severe
rheumatoid arthritis to an increased risk of generalized
bone loss.
The study population was 373 middle-aged,
mostly female patients who had low to moderate rheumatoid
arthritis. They'd been recruited to help evaluate the
effects of a gung-ho exercise program vs conventional
physical therapy.
Demographic and clinical data such
as age, weight and disease severity was collected. Rheumatoid
arthritis had been part of the patients' lives for around
seven years. The subjects had median scores of 27 for
the hands and feet, according to the Larsen scoring
system, which uses radiology to determine the extent
of bone erosion and joint space narrowing. Eighty-three
percent of them had never used corticosteroids, which
are confirmed culprits in bone loss.
The mineral density of the patients'
bones was assessed using a technique called dual X-ray
absorptiometry. Dr M C Lodder of VU University Medical
Centre in Amsterdam and colleagues discovered osteoporosis
in the neck in 6.5% of the women and in the spine in
12.6% of them. When the researchers took a peek at the
bone mass in those locales, a reduced amount of bone
was apparent in the neck in almost 19% of the women
and in the spine in nearly 21%.
When statistical associations between
rheumatoid arthritis and the demographic/clinical data,
as well as with the bone mass determinations, were explored,
a high Larsen score was found to be strongly associated
with a low bone mineral density (BMD) of the hip.
The researchers concluded that
there was "an association between high radiological
[rheumatoid arthritis] damage and low [BMD] at the hip,
which suggests an association between the severity of
[rheumatoid arthritis] and the risk for generalized
bone loss." Further, according to the researchers, bone
loss may occur even in "corticosteroid-naive patients."
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