Designer thyroid hormone holds promise as a cholesterol lowering drug
Thyroid treatment of under-active thyroid is associated with a significant decrease in serum cholesterol. However, thyroxine has not been used for the purpose of reducing cholesterol in persons who do not have underactive thyroid mainly because of the negative side-effects on the heart such as rapid or even irregular heart beats.
After trials in animals, an American-Swedish team lead by Professor John Baxter has shown(1) that a designer thyroid molecule (KB 2115) is capable of lowering serum cholesterol in human subjects with moderately high cholesterol over a 14 day period. No side-effects were reported.
It turns out that thyroid hormones bind to two types of receptors: the alpha receptor which predominates in the cardiovascular system and the beta receptor found in bone, liver and in other organs and which involved in the regulation of serum cholesterol. The challenge has been, therefore, to design thyroid hormone-related molecules that act specifically on the beta receptor to lower cholesterol.
Designer thyroid hormones have the potential to become a new cholesterol-lowering drug that can be used in persons unable to tolerate statins or as an additional drug in those where one drug is not enough to bring down cholesterol target levels.
Long-term studies involving more subjects are necessary to make sure that the designer thyroid hormones are safe particularly on heart and bone
- Berkenstam A, Kristensen J, Mellstrom K, Carlsson B, Malm J, Rehnmark S, Garg N, Andersson CM, Rudling M, Sjoberg F, Angelin B, Baxter JD, The thyroid hormone mimetic compound KB2115 lowers plasma LDL cholesterol and stimulates bile acid synthesis without cardiac effects in humans, Proc. Natl. Acad. Sci USA 105:663-667,2008
