Re: elaine - tsh question

[Guest guest]

Hi Lori Lou,

The TSH test really can be a nightmare. The pituitary hormone TSH can take as

long as 2 years to rise after you've been hyperthyroid. And although I have

abstracts and articles saying what a well known fact this is, many doctors

fail to realize this.

It has to do with false expectations and false promotions surrounding the

lab's ability to measure TSH. When we first developed tests for TSH, lab

people and endos promoted the notion that TSH alone was sufficient to

determine thyroid function. And it can help when we're screening new people

since TSH is the first parameter to drop when thyroid hormone levels start to

rise. But since those early days, we've found that TSH can lag way behind

thyroid hormone levels. We used to think this was because the pituitary

became ineffective after stopping to secrete TSH for so long. But more recent

studies show that the pituitary recognizes certain thyroid antibodies as if

they were TSH. Thinking we have enough, the pituitary doesn't start secreting

TSH until the antibody levels decline.

So in people without autoimmune thyroid disease, TSH can be helpful. But not

for us. If you go to www.suite101.com and find the article I wrote called The

TSH Nightmare, you can find a citation for a study that explains this.

Using this information, you can go to PubMed

http://www4.ncbi.nlm.nih.gov/PubMed/

and do a search for the title or author.

Print this abstract and take it along to your appt. Maybe when your doctor

sees how this is well-known, he'll at least do some research on it and

continue to keep an eye on your thyroid hormone levels without worrying about

TSH.

Let me know if you have trouble finding the abstract. Take care, Elaine

[Guest guest]

Thanks Elaine ... you are so helpful!

Lori

[Guest guest]

Elaine said...

> But more recent

> studies show that the pituitary recognizes certain thyroid antibodies as if

> they were TSH. Thinking we have enough, the pituitary doesn't start secreting

> TSH until the antibody levels decline

Aldyth Rae wrote:

> So does that mean that as my TSH went from <0.01 last month to 2.09 (r.r

0.4-6.4) this month I can take it as a good sign that my antibodies are coming

down?

Two comments;

DeGroot seemed less convinced by the antibody suppress TSH

hypothesis, despite the experiments injecting white blood cells

from Graves' patients into thyroidectomised lab rats (poor rats)

dropping their TSH. He seemed to think the old hypothesis had

some mileage, but I'm not familiar with the evidence for that.

Personally I think I'm convinced, as TSH is often lower in

Graves' patients at diagnosis than it is in people with other

form of hyperthyroidism at diagnosis, and I can't believe; we

are braver, complain less or take longer to diagnose, or even

that our hyperthyroidism is worse.

Whatever the cause it means TSH may err on the low side, making

patients look more hyperthyroid than they actually are. Thus the

advice at Thyroid manager to reduce antithyroid drugs when the

TSH reaches the bottom of the normal range (on the way up -- not

in block and replace obviously, but when the drugs are being

used to attain euthyroidism alone).

Either way TSH reappearing is a good sign, it might represent

less antibodies, but you want antibody tests to be sure of that,

why rely on inference when we can measure directly?

Any noticable change from the swich to 10mg yet? Even when they

go to too low a dose, some people take weeks or months to go

hyper again, but me and some others seem to notice it inside two

days.

We are all individuals, except for that chap in 'life of '

[Guest guest]

Hi Aldyth,

Yes, it's always a good sign of a response to ATDs when your TSH begins to

rise and it is TSH receptor antibodies (both stimulating and blocking) that

keep the levels low.

Blocking TSH receptor antibodies also keep the antibodies these low, and when

these predominate people move into hypothyroidism. So the TSH could still

remain low when TSI levels have fallen but blocking TSH receptor antibody

levels rise.

This is why some people can have very low FT4 and FT3 levels, lots of hypo

symptoms and still have a TSH level <.01.

With your TSH level rising nicely, you should be able to slowly reduce your

ATD dose. Take care, Elaine

[Guest guest]

Hi Aldyth,

Yes, it's always a good sign of a response to ATDs when your TSH begins to

rise and it is TSH receptor antibodies (both stimulating and blocking) that

keep the levels low.

Blocking TSH receptor antibodies also keep the antibodies these low, and when

these predominate people move into hypothyroidism. So the TSH could still

remain low when TSI levels have fallen but blocking TSH receptor antibody

levels rise.

This is why some people can have very low FT4 and FT3 levels, lots of hypo

symptoms and still have a TSH level <.01.

With your TSH level rising nicely, you should be able to slowly reduce your

ATD dose. Take care, Elaine