DEPRESSION OF THE SERUM CHOLESTEROL LEVEL IN MYXEDEMATOUS PATIENTS BY AN ORAL DOSAGE OF SODIUM DEXTROTHYROXINE WHICH HAS NO EFFECT ON THE BASAL METABOLIC RATE OR ELECTROCARDIOGRAM*†

Abstract

In the previous studies, it was found that high dosage (10 mg daily) of sodium dextro-thyroxine raised the metabolic rate and lowered the serum cholesterol level without an initial effect on the electrocardiogram. This was taken as pharmacologic evidence that the dextro-thyroxine was actually free of contamination by the levo-isomer. From 1 to 2 mg a day, in 3 successive cases of untreated myxedema lowered the serum cholesterol level in three or four weeks from 50 to 300, 330 to 215 and 375 to 280 mg per 100 ml, without raising the basal metabolic rates, which were at the end of the study, respectively, -36, -40 and -40 percent. The electrocardiograms also remained unchanged. These results suggest that the metabolic pathway by which dextro-thyroxine or its products produces the reduction in serum cholesterol concentration is independent of that by which it raises the BMR or potentiates the ECG.