Effect of renal transplantation on zinc metabolism and taste acuity in uremia. A prospective study

The effect of successful renal transplantation on zinc metabolism and taste acuity was determined prospectively in 15 adult uremic patients. Before transplantation all patients had subnormal concentrations of zinc in plasma and hair, as well as abnormal taste detection and recognition thresholds for sodium (salty), sucrose (sweet), hydrochloric acid (sour), and urea (bitter). Following renal transplantation, abnormalities of taste acuity and zinc metabolism persisted and were accompanied by increased urinary zinc excretion in all patients. Normalization of zinc concentration in plasma and hair as well as taste acuity did not occur until one year after transplantation and was associated with a concomitant decrease in urinary zinc excretion. The plasma zinc levels and daily urinary zinc excretion were inversely related (r = 0.62, P less than .001) in all patients with normal allograft function. None of the zinc parameters was significantly related to azathioprine or corticosteroid dosage. The results of this study suggest that zinc deficiency and taste abnormalities of uremia persist up to one year posttransplant and may be related to increased urinary zinc losses. The mechanisms underlying post-transplant hyperzincuria as well as clinical significance of zinc deficiency following transplantation remain to be determined.