Erythrocyte zinc concentration in patients with subacute thyroiditis

We have recently reported that red blood cell (RBC) zinc (Zn) in patients with hyperthyroidism reflects a patient's integrated thyroid hormone level over the previous few months. In the present paper RBC Zn concentrations were measured in 10 patients with subacute thyroiditis whose total plasma T4 and T3 levels were elevated. The values were compared with those obtained in 10 patients with untreated Graves' disease, whose plasma T4 concentrations were elevated to the same level as in the former group. The RBC Zn concentration was normal in 9 of 10 patients with subacute thyroiditis, but was depressed in all patients with Graves' disease. The mean (± SE) RBC Zn in patients with subacute thyroiditis was 162 ± 9 μmol/L, significantly (P < 0.001) higher than that in Graves' disease (87 ± 5 μmolμL). During prednisolone treatment the RBC Zn in patients with subacute thyroiditis remained at the normal level and did not change significantly, although it was slightly decreased at 2 and 4 weeks of treatment. On the...