Cognitive function in hemodialysis patients

Cognitive function was assessed in two groups of hemodialysis patients exposed to relatively low concentrations of aluminum in source water used to manufacture dialysate. One group of patients (long-term group) had been on dialysis for 5 years or more, the other (short-term group) for less than 5 years. Group comparison showed no significant differences of any cognitive measure. However, calculating an index of deterioration based on the discrepancy between current reading skills and current performance on the Wechsler Adult Intelligence Scale, five patients in the long-term group and two in the short-term group could be identified as functioning below their predicted premorbid optimum level. There was no correlation between cumulative exposure to water-born aluminum and any of the measures of cognitive function in either of the groups. There was a statistically significant negative correlation between the cumulative amount of aluminum prescribed to be taken orally and performance on cognitive tests in the long-term group. This observation strengthens the case for minimizing the prescription of aluminum-containing gut phosphate binders.