Lunar DPX-IQ, Operator'S Manual, Page: 143 / 166

DPX-IQ Operator’s Manual Comparison to Reference Population I-1
Appendix I Contents
I.1 Reference Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1
I.2 Reference Population Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-2
I.3 Age Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-7
I.4 Weight Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-8
I.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-9
Use of the reference population comparisons is fully at the discretion of the
clinician.
Revised 1/99C
Appendix I:Comparison to Reference Population
I.1 Reference Data
The reference data for the LUNAR DPX were based on ambulatory subjects from the
general population who were free from chronic diseases affecting bone and who were
not taking medications which influence bone (such as corticosteroids, anticonvulsants
and thyroxine). Subjects were from the US and Northern Europe (UK, Scandinavia).
As additional data becomes available, the reference database will be increased and the
tabular materials updated to reflect these changes.
In the past, reference values obtained with a different instrument (LUNAR DP3) have
been shown to be virtually identical in different white populations (US, Australia, UK,
Spain, Brazil, Argentina).
1–6
Variations within normal limits of nutrition and physical
activity have not been demonstrated to have a significant influence on reference
values, but body weight does have some influence.
1,7
Race can have an influence, as
bone mineral density (BMD) in black subjects is about 8-12% more dense than in
whites.
8-14
Hispanics have a somewhat higher BMD (2–4%) than whites.
13
People of
Asian descent may be a few percent lower, but this difference appears to be associated
with a smaller body size.
12,15,16
Also, the inclusion of subjects with skeletal fractures in
an elderly reference group could influence such data by lowering the average BMD
since patients with fractures are usually 1 SD below age-matched controls without
fractures. Consequently, all patients with fractures were excluded from our
reference group.
I
Comparison to
Reference Population