TOTAL FREE TOCOPHEROLS IN THE SERUM OF PATIENTS WITH THYROID DISEASE"

The extent of muscle disease encountered at a given level of clinical hyperthyroidism varies from mild subjective weakness to severe disabling my-opathy (1). Inconstancy and variable severity of muscle involvement point to some factor apart from the thyrotoxic state per se in its genesis. The possibility that exhaustion of tocopherol stores is the critical variable is raised by analogy between the dystrophic morphologic changes, increased oxygen consumption, hypercreatinuria, and de-pletion of muscle creatine which accompany thy-roid hormone excess in animals and man (2-6), and similar alterations due to tocopherol deficiency in rodents (7-11). The mechanisms of these changes are not established, but there is evidence that in both hyperthyroidism (12-14) and tocoph-erol deficiency (15, 16) impairment of high energy phosphorylations results in uncontrolled release of energy derived from biological oxidations. The possibility of tocopherol depletion in thyro-toxicosis is supported by evidence of accelerated turnover of other vitamins (17), cholesterol (18), and calcium (19) in hyperthyroidism. Increased tocopherol requirement in the hyperthyroid state is suggested by susceptibility of chicks given ex-cess thyroid hormone to vitamin E deficiency (20). Of further interest are the reports of prevention of thyroxine induced creatinuria in rats (21) and children (22) by a-tocopherol. These considera-tions stimulated the present survey of the concen-tration of tocopherols in sera of patients with thy-roid disease. METHODS Subjects. Observations were made on 115 persons classified as follows: a. Twenty-nine consecutive patients in whom the diag-nosis of Graves ' disease was made on clinical grounds and supported by measurement of basal metabolic rate, 24-hour thyroidal uptake of radioactive iodine and, i