Zinc, copper, manganese, and selenium metabolism in thyroid disease.

This study was designed to evaluate trace metal metabolism in adults with thyroid diseases. Erythrocyte zincvaluesweresignificantly lowerthannormal in hyperthyroidism and higherinhypothyroidism. A significantly higherthan normal urinary excretion of zinc was observed inhyperthyroidism. The mean concentrations of plasma and erythrocyte copper were significantly abovenormal inhyperthyroidism. Plasmaseleniumlevelswere significantly lower than normal in hyperthyroidism. No statistically significant difference was found in plasma zinc, erythrocyte manganese, or urine copper values between patients with thyroid diseases and healthy controls. The erythrocyte manganese content correlated well with thyroxine and triiodothyronine levels. Plasma prealbumin and retinol-binding protein correlated well with the erythrocyte zinc content but not with plasma zinc levels. There was no correlation between erythrocyte superoxide dismutase activity and erythrocyte copper or zinc concentrations. The results of this study suggest that the metabolism of zinc, copper, manganese, and selenium is abnormal in thyroid dis- eases. Am J C/in Nuir l984;40:26-35.