Aluminum toxicity in relation to kidney disorders.

Aluminum toxicity in patients with chronic renal failure has been related to renal osteodystrophy and dialysis encephalopathy (DES). The toxicity is associated with renal osteodystrophy in two ways. One association is the iatrogenic effect of excessive use of aluminum hydroxide gels resulting in hypophosphatemia which interferes with bone mineralization. The second association may involve deposition of aluminum in bone owing to aluminum being absorbed during hemodialysis. Evidence for this second association has been gathered from epidemiological studies of hemodialysis centers and their practices of using either tap water high in aluminum in the dialysate, or aluminum-free deionized water. In patients with DES, aluminum accumulation in the brain has been clearly shown to come from either the ingestion of aluminum containing phosphate-binding gels, aluminum in the dialysate, or a combination of the two. The outbreak of the DES also has been well-correlated with the sudden elevation of aluminum in tap water owing to the use of large amounts of aluminum in water treatment plants. Whether aluminum itself or a combination of aluminum and other factors causes DES is not understood at this time.