Bone disease in long-term hemodialysis patients with low dialysate aluminium

The dialysis unit in Sunderland uses softener water treatment with low Al concentration (dialysate mean Al 22 micrograms/L) but employs continuous oral Al (OH)3 to control serum phosphate. Thirty-one patients, 22 males and 9 females, with a mean age of 45 years, maintained on hemodialysis for a mean of 48 months were studied. Patients had higher Al concentrations than normal controls (p less than 0.001) and the postdialysis serum Al levels were also significantly higher than the predialysis levels. Twenty-four of 31 patients had evidence of hyperparathyroidism on radiology but only 4 of 31 had fractures. From a histopathological point of view, the patients were found to have no lesions (4 patients), osteitis fibrosa alone (17 patients), and osteitis fibrosa combined with osteomalacia (5 patients). The effect of 1-alpha(OH)D3 treatment was checked by repeated bone biopsies. One case of the last group showed no improvement of osteitis fibrosa, while osteomalacia progressed to severe. We conclude that both antacids and dialysate contribute to the serum and tissue Al accumulation in Sunderland Renal Unit, where over a period of ten years only one patient developed Al-related osteomalacia.