Reduction of Serum Cholesterol by Sodium Dextro-thyroxine in Euthyroid Subjects

Abstract

In 25 euthyroid subjects with mild to modest hypercholesterolemia sodium dextro-thyroxine (DT4), in doses of 4 to 8 nig/day, caused a reduction of serum cholesterol from a mean control value of 294 mg/100 ml to a mean therapy value of 236 mg, an average decrease of 58 mg/100 ml (20%). The decline occurred in subjects with initial normal serum cholesterol as well as in those with initial high values, nor did the degree of initial elevation influence the result. It required, on the average, 3 weeks of therapy to produce the fall and placebo substitution or omission of therapy was followed by a rebound rise to the initial value in 4 weeks. Side effects were rare in non-cardiac patients. There were no adverse effects in 10 of 12 patients with mild angina pectoris. One patient suffered a coronary occlusion within 1 day of interrupting therapy for aggravation of angina. DT4 was compared to sodium levo-thyroxine (LT4) and a placebo in a double-blind experiment in 76 normocholesterolemic prisoners. DT4 reduced the cholesterol at dose levels of 6, 8 or 10 mg daily without causing a rise in BMR, whereas LT4 reduced the cholesterol only at a dose which elevated the BMR. DT4 is an efficient safe cholesterol-lowering agent but must be administered with caution in patients with coronary heart disease. There is no evidence at the present time that DT4 alters the course of atherosclerosis or prevents its onset.