Effect of hemodialysis on the hypersulfatemia of chronic renal failure.

Concentrations of sulfate can increase eightfold in the blood of patients with severe reductions in glomerular filtration rate. Sulfate enters the body almost exclusively as the amino acids cysteine and methionine, and leaves in the urine predominantly as inorganic sulfate. Concentrations in plasma may exceed 2.5 mol/L in renal failure, and raise the anion gap by 5 mEq/L. In studies by the author and colleagues, hemodialysis using large dialyzers and brisk blood flow rates effectively lowered the concentrations of sulfate in plasma to normal in the immediate post dialysis period; the sulfate reduction ratio actually exceeded the urea reduction ratio. Significant correlation was observed between the two ratios. Concentrations of sulfate, in conjunction with other data, may prove useful for estimating dietary intake of protein and monitoring control of acid-base balance.