Question:Are there any places on the web which post the meaning of BMD test
scores. I realize that size and weight make a difference. But what
about general guidelines?
Answer:I have been doing some investigation myself in the last few months as to the
meaning of BMD test scores and what is meant by "a T-score or a standard
deviation" as my GP and the Osteoporosis specialist at the hospital seemed
incapable of explaining these in a straightforward and understandable way
(which rather led me to the conclusion that they didn't understand the
terminology themselves - at least our GP had the courage to admit eventually
that "he hadn't a clue what a T-score was")
Anyhow it seems (as is so often the case with jargon) that it
is actually quite simple - the T-score is the number of standard deviations
from the 'normal' spectrum of bone density for a person of that age weight
and ethnic origin where one standard deviation is equivalent to a reduction
in bone density of 0.12 grams per square centimetre (see later for further
comment) the current "definition" of Osteoporosis being more than 2.5
standard deviations from the density of a normal 35 year-old.
The only problem with this is that the definition of
Osteoporosis has been changed over the years (with the encouragement of the
drugs industry cynics might say) from its original concept of a condition of
severely increased bone fragility causing fractures of the bones to its
present definition where the 'disease' (if disease it be) is now having
supposedly brittle or fragile bones with a supposed consequent increase in
fracture risk - analagous perhaps to defining heart disease as having high
cholesterol. Others even more cynical might say it is rather like saying
that grey hair or wrinkles is a disease - in fact why not go the whole hog
and say that getting older is a disease. Anyhow the upshot of this subtle
redefinition of Osteoporosis is that hey presto a significantly increased
percentage of women are now suffering from this 'disease' which just happens
to allegedly be treatable by HRT which these poor women have to take for
years on end despite it exposing them to a plethora of side affects and
risks and them being left in no better position vis-a-vis Osteoporosis when
they have to come off HRT after 10 years (to go on beyond 10 years
apparently increases the risks dramatically) than if they never went on it
in the first place.
