Evidence of increased parathyroid activity on discontinuation of high-aluminum dialysate in patients undergoing hemodialysis

High-aluminum dialysate exposure has been incriminated in the pathogenesis of vitamin D-resistant osteomalacia in patients undergoing long-term hemodialysis. Parathyroid-mediated osteitis fibrosa is rare in these patients. Thirteen patients undergoing long-term hemodialysis were transferred from a center (Unit A) where water used to prepare dialysate was high in aluminum (100 to 450 μg/liter) to a new center (Unit B) where dialysate was highly purified (aluminum concentration less than 10 μg/liter), and changes in calcium metabolism were studied over a 12-month period. After transfer of patients to Unit B, serum aluminum levels fell (p < 0.01), whereas serum immunoreactive parathyroid hormone levels rose (p < 0.01) over 10 months. Over this time, predialysis serum calcium levels did not alter significantly, whereas postdialysls serum calcium levels declined slightly (p < 0.05). Serum phosphate levels did not alter. Serum alkaline phosphatase levels rose progressively in Unit B (p < 0.001). Discontinuation of dialysate high in aluminum in patients undergoing long-term hemodialysis may facilitate a rise in parathyroid activity.