THE PROPHYLAXIS and arrest of progression of atherosclerosis has become the subject of intensive research in recent years. Lipid metabolism has occupied a prominent position in investigation on this subject.
Turner1 and Menne2 et al. have shown that the administration of dessicated thyroid gland to animals fed large amounts of cholesterol tended to prevent the formation of atherosclerosis. The calorigenic effects of thyroid hormone prohibit its use in many patients, particularly those with coronary arteriosclerosis. The dextro-isomer of thyroxine has been shown to exert an effect on serum cholesterol comparable to that of dessicated thyroid or levothyroxine, the naturally occurring thyroid hormone. Dextrothyroxine, however, exerts a lesser calorigenic effect. While D-thyroxine possesses only from 1% to 2% of the cardiac-stimulating activity of Lthyroxine in raising the pulse rate in laboratory animals, it has about 16% of the potency in reducing serum cholesterol.3 This disproportion of effect on