Ceruloplasmin and vitamin E levels in toxic multinodular goiter

The effect of the enhanced metabolic rate over antioxidant status was investigated in hyperthyroid individuals. Serum total T3 and T4 levels were measured by radioimmunoassay in 45 patients and 25 controls. The serum vitamin E was assayed fluorometrically in the hexane extract of serum. Serum ceruloplasmin activity was measured spectrophotometrically. Statistical significance was asessed by correlation regression analysis and paired t-test. The serum vitamin E levels decreased significantly as the levels of the thyroid hormones increased. For ceruloplasmin the opposite changes were observed: mean serum ceruloplasmin of hyperthyroid patients was greater than that of control group. Although the changes in vitamin E and ceruloplasmin concentrations did correlate with the levels of thyroid hormones in hyperthyroid patients, we observed no associations between these parameters in the euthyroid state. As these two parameters are the measure of oxidation potential, it may be suggested that raised free radical activity in hyperthyroidism cause the increased oxidative stress and increased general radical scavenging. The present data may indicate a direct effect of thyroid hormones on vitamin E and ceruloplasmin metabolism.