TASTE ACUITY IN PATIENTS UNDERGOING LONG-TERM HEMODIALYSIS

Recognition taste thresholds for the four primary tastes, sour, sweet, salty, and bitter, were determined in 18 patients (age range, 17 to 65 years) with end-stage kidney disease and were compared to 10 age and sex matched controls. In experimental subjects, mean taste thresholds before and after dialysis for tartaric acid were 0.004 N and 0.002 N, respectively, compared to 0.0002 N for controls. For sucrose, before and after dialysis, mean taste thresholds were 0.039 M and 0.023 M, respectively, and 0.014 M for controls. When we used the same taste modalities that is, sweet or sour, all possible comparisons were significant except the one for sweet between patients after dialysis and controls. Mean recognition taste thresholds for salty and bitter were not significantly impaired in dialysis patients when compared to controls. Mean serum zinc concentrations were 77 μg/dl, both before and after dialysis. Since these are low-normal values, zinc could be a contributing factor in loss of taste among these patients, but it cannot explain the improvement seen in taste acuity associated with dialysis for 6 to 8 hours. Since taste acuity improved with dialysis, it is conceivable that recognition taste thresholds could be adapted so that they could complement or substitute for the current serum urea kinetics calculations used in many programs to assess the adequacy of dialysis.