Thyroid hormone-like effects without thyrotoxicosis during one year's therapy with NA-DT3 for hypercholesterolemia.

A thyroid hormone analogue, sodium dextro-triiodothyronine (NaDT3), at a dosage of 1 mg/day for 1 or 2 yr, decreased serum cholesterol levels about 30% in 26 hyperlipidemic adults. There were less sustained decreases in the serum phospholipids, and occasional lowering of the serum triglycerides, but no effects on body weight, blood pressure, or pulse rate. Changes recognized as variable concomitants of spontaneous or induced thyrotoxicosis, such as transient increases in fasting blood glucose, calcium, and globulin, persistent rises in alkaline phosphatase, and nonsustained decreases in hematocrit are consonant with the fact that Na-DT3 exerts about one tenth of the thyroid hormone activity of LT3. These changes, however, appear to represent actions of iodinated amino acids apart from those effects that result in clinical thyrotoxicosis.