[Bioenergetic radiographic absorptiometry in hemodialysis]

In order to assess bone loss in uremic renal osteodystrophy (URO), we have measured total and regional mineral bone density (TMBD and RMBD, respectively) by using bioenergetic radiographic absorptiometry (BRA) in a population of patients on hemodialysis (HD). Thirty one patients have been evaluated, with a mean age of 55 and a mean time on hemodialysis of 31 mo. (range 2-120 mo.). Bone absorptiometry consisted of measurement of total body (TMBD) and regional analysis of head, upper limb, lower limb, ribs, pelvis and spine (RMBD). TMBD inversely correlated with alkaline phosphatase and parathyroid hormone levels; it also correlated inversely with age, but only in females. TMBD showed significantly lower values in HD patients than in chronic renal failure patients and controls. All the regional parameters correlated inversely with alkaline phosphatase levels.

BRA is a non invasive method which quantifies TMBD and RMBD with a very low radiologic exposure and correlates adequately with levels of alkaline phosphatase and parathyroid hormone in URO. TMBD measures total cortical bone of the skeleton with good accuracy, RMBD allows a selective analysis of regional bone changes and a evolutive control in these patients, given the nonuniform decrease of mineral density in the skeleton.