TSH and cholesterol relationship

[Miraclesky]

Does elevated TSH increase cholesterol or only low T3 increases cholesterol ?

[greygoose]

There is no direct connection between TSH and cholesterol levels.

And, it's not exactly correct to say that low T3 increases cholesterol, it doesn't. The amount of cholesterol produced by the liver is always the same. It's just that when T3 is low, the body cannot handle cholesterol efficiently, and it tends to mount up in the blood. Increase the T3, and the cholesterol will be used in the body and excreted normally.

And, the connection with TSH is that when the FT3 is low, the TSH will be high. But, that's as far as it goes.

[Miraclesky in reply to greygoose]

Thanks for the reply, that's very helpful

[greygoose in reply to Miraclesky]

You're welcome.

[helvella Administrator Thyroid UK]

In many people, the two states go together.

If you have high TSH but "normal" T3, or "normal" TSH but low T3, you are already something of an oddity.

In general, TSH itself seems to have limited effects beyond the thyroid gland itself. (There are various suggestions such as an effect on bones.) It seems most likely it is low thyroid hormone that results in higher cholesterol.

[Miraclesky in reply to helvella]

Thanks for the reply , when you said low thyroid hormone, you meant low free t3 (ie) below normal range , right ?

[helvella Administrator Thyroid UK in reply to Miraclesky]

I was deliberately being vague.

Inevitably the actual action is achieved by the action of T3 (little research suggests a direct action of T4). But that T3 doesn't necessarily get reflected in blood T3 level.

The liver, in particular, is known to convert T4 to T3 - of which some gets into the bloodstream, but some of that T3 acts locally on the very cells that converted the T4 into the T3, or near-neighbours.

Therefore it seems wrong to concentrate solely on blood T3 levels.

[Miraclesky in reply to helvella]

Thanks for the explanation