HDCN Article Review/Hyperlink

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 osteodystrophy.

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 considerably 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 treatment?

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)