Packham DK, Ebeling PR, Wark JD, Becker GJ
Prevalence and risk factors for osteopenia in dialysis patients
Am J Kidney Dis
(Oct) 28:515-522 1996
These authors determined bone mass
using DEXA at several sites in 250 dialysis patients. They found severe
bone loss (>2sd below aged matched normals) in 8 % of patients at the
lumbar spine, 13% at the femoral neck and 20% at the wrist. These
findings would place these patients at high risk for fracture. In the
whole population they found Z scores (a Z score of -2 = -2 Standard
deviations below the mean for age matched normals) reduced 0.67 at the
femoral neck and 1.01 at the wrist, but increased by 0.29 in the lumbar
spine; all of these changes were statistically significant.
The likelihood of osteopenia was enhanced by prior transplant and
secondary amenorrhea, but reduced if the patients had had a
parathyroidectomy. Duration of dialysis did not influence osteopenia,
which, they imply, probably exonerates heparin as a problem in renal
Based on these data the authors suggest following DEXA measurements to
identify patients that need more intensive evaluation of their bone
lesion. In other words, do this expensive test ($300 or more) and then
assess the patient for renal osteodystrophy.
Comment: While these data are of interest, there would appear to be
more information to derive from them. First, was there any difference
between the 90 PD and the 160 HD patients? Second, was there any
relationship to PTH levels (which are the best non-invasive indicator of
the bone lesion)? Third, was there relationship to the cause of the
patient's renal failure or prior (unrelated to transplant) steroid
Perhaps a recommendation that might be made, without any data, is that
DEXA should become a part of pre-transplant screening. At least those
13% of patients with severe osteopenia (i.e., more than 2 SD below the
normal mean) at the hip might be considered high risk for fracture if
transplanted and possibly encouraged to remain on dialysis.
In summary, this is an interesting and provocative article. The authors
should be encouraged to further assess their data along the lines
suggested. This data does not support the routine use of bone mass
measurements in the dialysis population. It certainly establishes the
need for more information of this sort, paticularly focusing on the
relationship of the bone mass measurements to the various bone lesions.
Future studies of intervention trials in renal osteodystrophy would also
be well advised to include bone mass as one of their outcome measures.
(Donald Sherrard, M.D., University of Washington)