ALUMINUM-INDEPENDENT ADYNAMIC BONE-DISEASE IN UREMIA - CLINICAL RELEVANCE AND PROGNOSIS

Adynamic bone disease (ABD) is a histological bone pattern which is mainly caused by a decreased bone matrix formation. Therefore it is diagnosed by a low bone formation rate. The mineralization process is not as much decreased so that the osteoid seam is not increased as in osteomalacia. This histological pattern was first observed in patients with aluminum overload due to the long-term intake of aluminum-phosphate binder. The etiological role of aluminum is well proven but always in association with a relative hypoparathyroidism, this latter being possibly also caused by aluminum overload of the parathyroid glands. However we have observed ABD in 4 patients on dialysis and in 2 uremic patients not yet on dialysis in the absence of aluminum overload because aluminum-phosphate binder had been excluded from their treatment. These patients had no hypothyroidism, no steroid therapy, no diabetes, no iron or fluorid intoxication, no hypophosphatemia or acidosis i. e. factors known to depress bone formation. In spite of no previous parathyroidectomy, they had relative hypoparathyroidism for the degree of their renal failure. This idiopathic ABD seems to have a prognosis not as bad as that of aluminum ABD since when the patient stays on dialysis this histological pattern can be reversed to that of hyperparathyroidism.