Prevalence of histological types of bone disease in a hemodialysis center limiting the oral intake of aluminum hydroxide

UNLABELLED: To assess the prevalence of histologic bone disease in our center where Al(OH)3 intake is restricted, we reviewed 42 bone biopsies performed between 1975 and 1985 in patients dialyzed more than 29 months. Bone biopsies were performed systematically (2/3 of the cases) or because of a mild hypercalcemia (1/3 of the cases). Seventeen of these patients had been dialyzed before 1978 with softened water moderately contaminated by aluminum. Fifteen had always been dialyzed with reverse osmosis treated water and 10 had been exclusively treated by hemofiltration. The prevalence of osteitis fibrosa was 76%, that of osteomalacia null and that of adynamic bone disease 24% (but only 9.5% with positive Aluminon staining). When the 17 patients dialyzed with aluminum contaminated water before 1978 were excluded, only one patient among 25 had an aluminum adynamic bone disease (4%). This low prevalence can probably be explained by the restricted intake of Al(OH)3 thanks to the systematic administration of Ca CO3 and in a few cases of Mg (OH). The adynamic bone disease group has lower serum concentration of PTH and shorter duration on dialysis whereas the serum levels of calcium, phosphorus, magnesium and aluminum and daily dose of Ca CO3, Mg (OH)2 and Al(OH)3 do not differ. The frequency of the positivity of aluminum staining is not statistically different in the 2 groups. In 4 cases, adynamic bone disease without aluminum or iron intoxications is found, associated with a relative hypoparathyroidism. It is not explained by previous parathyroidectomy, diabetes or steroid therapy. CONCLUSIONS: 1) Restriction of aluminum intake and dialysis with reverse osmosis treated water lead to a low prevalence of aluminum bone disease. 2) A new bone disease in uremia is described: the idiopathic adynamic bone disease associated with a relative hypoparathyroidism.