T3 half life

[Guest guest]

Sheila,

You wrote:

>

> ... I have stated before, this forum is to help and support patients, it is

> not a Medical School - and we are not scientists.

Well, I'll stop trying to confuse you all with facts, then.

You seem pretty invested in believing that the biological half life of

T3 is only 8 hours, so you are welcome to keep giving advice based on

that. And, please keep telling people that NutriThyroid is giving their

glands nutritional support that they can't get from food. BTW, there are

trace amounts of T4 and T3 in meat, as well as in this product. I did

the calculation one time and showed that you actually ingest more from a

meal than you do from the standard dose of NutriThyroid. But, you don't

have to believe that, either.

Chuck

[Guest guest]

I would hazzard a guess that you mean raw meat? Not something we tend to eat

> > ... I have stated before, this forum is to help and support patients, it

is > not a Medical School - and we are not scientists.

Well, I'll stop trying to confuse you all with facts, then.

You seem pretty invested in believing that the biological half life of T3 is only 8 hours, so you are welcome to keep giving advice based on that. Chuck

------------------------------------

TPA is not medically qualified. Consult with a qualified medical practitioner

before changing medication.

[Guest guest]

HI Chuck

You wrote:

>

> You wrote:

> >

> > ... I have stated before, this forum is to help and support

patients, it is

> > not a Medical School - and we are not scientists.

>

> Well, I'll stop trying to confuse you all with facts, then.

>

> You seem pretty invested in believing that the biological half life

of

> T3 is only 8 hours,

In Sheila's defence, I think the point she was trying to get across

to you is not that we don't believe you or do not care about the

facts, but that this is a small point for a patient, and lets get on

to other topics.

This is a patient support group, ie patients supporting each other

through a difficult and soul destroying disease, which is

misunderstood and mismanaged by many doctors within the NHS.

Therefore as most of us do not have degrees in science, arguing over

the exact half life of T3 will have no overall benefit to us as

patients.

It sounds to me from your various posts on this topic and that of

nutri thyroid, that you DO have a fair amount of background knowledge

in this area, and that you feel that some of the information we have

been given is inaccurate. (and I should say at this point I don't

entirely disagree with you on the Nutri front). HOWEVER...

....and this may a personal thing, but I feel that many of your posts

seem to come less from a position of wanting to help your fellow

sufferers on this forum, and more from a position of arguing minor

points to prove Sheila wrong.

I hope I have got this wrong - because someone with as much knowledge

as you have could be a real asset to the forum, and really help us

understand some of the tougher concepts. However you have to

understand that we all respect Sheila and what she has done for us,

and we all know that she really is not in this for anything else but

to get the best for us all. Any errors she has made are not by

design - she's just a patient like the rest of us (though a lot more

driven!!)

Leah

[Guest guest]

,

You wrote:

>

> I would hazzard a guess that you mean raw meat? Not something we tend to eat

Well, actually I did not account for thermal degradation, which would

have turned about 10% of the T4 into T3. I don't recall whether that

would have been close enough to give the nod to NutriThyroid.

Here's a paper from 1989 that showed that the levothyroxine in lightly

cooked beef is not significantly degraded. You just need to order medium

rare, rather than well done.

o Wortsman, Dimitri C. Papadlmitrlou, Marietta Borges, and

Defesche, " Thermal Inactivation of L-Thyroxin " CLIN. CHEM. 35/1, 90-92

(1989) 90 CLINICALCHEMISTRY vol. 35, No. 1, 1989.

We assessed the extent of inactivation of L-thyroxin induced

by exposure to heat in the presence of two vehicles. Preparations

of L-thyroxin in the dry powder form, or dispersed in the

solvents propylene glycol (water-like) or ethoxylated castor

oil (oil-like), were heated at temperatures ranging from 65 to

160 degrees C, 5- to 15-mm periods. Heating L-thyroxin to a

temperature below that of cooked bovine ground meat

produced <10% degradation. Thermal degradation

was pronounced only above 90 degrees C, and was almost completed

at 160 degrees C. Tri-iodothyronine was the only thermal degradation

product identified after L-thyroxin was heated at

125 degrees C. In a separate experiment we measured the melting

point of L-thyroxin, 148.81 degree C value agrees closely with

the observed thermal sensitivity. We conclude that L-thyroxin

is not significantly degraded under conditions encountered

during cooking of ground bovine meat for short times at

moderate temperatures.

Chuck

[Guest guest]

Chuck,

The point upon the half life of T3 is that it shortness, according

the establishment, makes it dangerous. Its shortness causes

excessive mood swings. Danzi, et al., have shown that, although

their measurement of T3 in the serum had a half-life of 8 hours, the

effect of the T3 in the nuclei had a half-life of 2 days. The

difference is substantial. Instead of having an 8:1 shift in T3

intensity in the serum just after taking a one-per-day dose, the

effect has a 1.4:1 shift in level.

Now if your data shows a longer half-life for T3 then the " danger "

of T3 is even less and the " danger " claim is even more rediculous.

Please note that it is this false claim that we are trying to

destroy. And we are trying to do this as well as destroy other

false allegations made by the endocrinology establishment so that

these folks might actually be treated properly with the honesty and

dedication required by numerous statements of medical ethics.

Have a great day,

> >

> > ... I have stated before, this forum is to help and support

patients, it is

> > not a Medical School - and we are not scientists.

>

> Well, I'll stop trying to confuse you all with facts, then.

>

> You seem pretty invested in believing that the biological half

life of

> T3 is only 8 hours, so you are welcome to keep giving advice based

on

> that. And, please keep telling people that NutriThyroid is giving

their

> glands nutritional support that they can't get from food. BTW,

there are

> trace amounts of T4 and T3 in meat, as well as in this product. I

did

> the calculation one time and showed that you actually ingest more

from a

> meal than you do from the standard dose of NutriThyroid. But, you

don't

> have to believe that, either.

>

> Chuck

>

[Guest guest]

Hi, Leah. Please see responses below...

..

..

> It sounds to me from your various posts on this topic and that of

> nutri thyroid, that you DO have a fair amount of background knowledge

> in this area, and that you feel that some of the information we have

> been given is inaccurate. (and I should say at this point I don't

> entirely disagree with you on the Nutri front). HOWEVER...

..

..

Chuck is very modest so he tends to NOT discuss his credentials unless

really pushed. Suffice it to say that he speaks from a world view very

firmly based in the best traditions of science...

..

..

>

> ...and this may a personal thing, but I feel that many of your posts

> seem to come less from a position of wanting to help your fellow

> sufferers on this forum, and more from a position of arguing minor

> points to prove Sheila wrong.

..

..

I've known Chuck for some time, and I've never seen this tendency. But

when he makes a statement about a matter of science and chemistry it is

based upon a very thorough knowledge and experience in that field, and

will most likely be well supported by peer reviewed literature in the

field. Thus when he says something is typically XX he is not generally

giving you something he read in yesterday's newspaper; but rather the

best information that is available from the most intelligent and

educated people in the field. None of which means that on some

particular matter Sheila might not well be right and Chuck wrong.

One thing we should realize: In science words tend to have rather

specific meanings; and many times those meanings are different than you

or I as lay persons would mean. This precision in speaking can be

off-putting to some people at times. But if you think that's bad you

should [if you haven't] try reading some of the peer reviewed papers

Chuck mentions. I assure you there's a warm and caring human under the

exterior he presents. Just don't let him drive your Hummer; he'll get

mud all over the wheels! [ggg]

..

..

>

> I hope I have got this wrong - because someone with as much knowledge

> as you have could be a real asset to the forum, and really help us

> understand some of the tougher concepts. However you have to

> understand that we all respect Sheila and what she has done for us,

> and we all know that she really is not in this for anything else but

> to get the best for us all. Any errors she has made are not by

> design - she's just a patient like the rest of us (though a lot more

> driven!!)

>

> Leah

..

..

Certainly Sheila is to be commended for her work here. I'm more than a

little embarrassed that I have probably contributed to her monumental

work load recently, although I didn't intend to. I believe your

evaluation of Sheila is right on. I suspect that if you know Chuck for

a while you will also have an immense respect for him too; not only as a

scientist but as a caring human being. You probably won't learn

anything about his personal tribulations until you know him for a while.

And now I'm _really_ in trouble; because not only will he seldom toot

his own horn; he hates it when others do...

Regards,

[Guest guest]

I need the science that does not support BTA's position Chuck.

Sheila

Leah,You wrote:> ... (10 is the new advisement by the> BTA). Also they say that thyroxine is the only apropriate treatment.....I'll go out on a limb and say the science does not support the BTA's positions. :)Chuck

No virus found in this incoming message.Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.6.14/1643 - Release Date: 30/08/2008 17:18

[Guest guest]

Hi, Leah. See responses below...

..

..

> Please also forgive us if we don't necessarily believe a statement

> just because it " scientifically correct " . As a result of doctors in

> the UK basing their decisions on science, many of us have not been

> treated until our TSH is over 5.5 (10 is the new advisement by the

> BTA). Also they say that thyroxine is the only apropriate treatment.

> The advice of one of the leading professors in the UK is that if a

> patient has a TSH within range then any hypothyroid symptoms are

> a " somatoform disorder " as the " science " is definitely correct.

..

..

I've just uploaded a post that echoes much of what you've said about the

problem. If you can see any modifications or additions please jump

in... There's an old saying: " The law is an @$$ " . Perhaps at times we

can apply that to science [or at least some scientists] too? [ggg]

..

..

>

> Looking forward to seeing more of Chuck's soft underbelly!

..

..

I'll leave you and Chuck to work that one out! [ggg]

..

..

>

> Leah x

[Guest guest]

Sheila,

You wrote:

>

> I need the science that does not support BTA's position Chuck.

That seems to be all of the science.

I don't mean to be politically partisan, but you should look for a

political or fiduciary motive for the BTA to ignore the real science.

How much money is saved by not supplying medications to people with

borderline test results? Is there a down side? Your medical care system

seems to be engaging in rationing. I don't think the motive is science.

Poor interpretation of the science is just an excuse, a cover.

Chuck

[Guest guest]

For all of you that requested the T3 half life data that and I

exchanged, I have attached the Belgian paper from last year, that

sent me, which measured T3 accumulated over a 24 hour period in urine to

gage the effectiveness of combined T4-T3 medication. I think if you see

a T3 half life of 6-8 hours cited, the paper will most likely be on

rats. Dogs are at about 8 hours, and guinea pigs 17. Except for the

paper on circadian rhythms (0.75 d), all the human T3 half lives have

been at least 1 day. The highest was 2 days.

Here are citations for some other work on the same question. The first

is the page of Abbott Labs, which (IIRC) gives the serum half lives for

T4 at 6.7 days and T3 at 1.5 days:

http://www.abbottdiagnostics.com/Your_Health/Thyroid/function.cfm#t3

The very first measurement of T3 half life was in rats. This may be the

source of all the confusion. Human studies came later.

J. H. Wilkinson, W. E. Sprott, C. H. Bowden, and N. F. Maclagan " The

biological action of substances related to thyroxine. 8. The effects of

butyl 4-hydroxy-3:5-diiodobenzoate on the deiodination of diiodotyrosine

and thyroxine in rats, " Biochem J. 1954 February; 56(2): 215–222.

There are lots of reviews that give 1 day for humans, but I could not

find solid citations except for this one. It may have been the one they

all have " common knowledge " about. You can trace papers that cite this.

Note the variation with thyroid status. Several of the papers said 1 day

was an " estimate " rather than a precise determination.

T. Nicoloff, C. Low, H. Dussault, and Delbert A. Fisher,

" Simultaneous Measurement of Thyroxine and Triiodothyronine Peripheral

Turnover Kinetics in Man, " J Clin Invest. 1972 March; 51(3): 473–483.

Here's the abstract:

Serum triiodothyronine (T3) kinetics in man have been difficult to

define presumably due to the interference of iodoproteins generated

during the peripheral metabolism of T3. The use, in the present study,

of an anion-column chromatographic method for separation of serum T3 as

well as thyroxine (T4) from these iodoproteins has overcome this

technical handicap. Simultaneous measurement of serum 125I-T3 and

131I-T4 kinetics were performed in 31 subjects from the clinical

categories of euthyroid, primary hypothyroid, thyrotoxic and

posttreatment hypothyroid Graves' disease, factitial thyrotoxic, and

idiopathically high and low thyroxinebinding globulin states. The normal

mean T3 fractional turnover rate (kT3) was 0.68 (half-life = 1.0 days),

increased in toxic Graves' disease patients to 1.10 (half-life = 0.63

days), and decreased in primary hypothyroid patients to 0.50 (half-life

= 1.38 days). The mean T3 equilibration time averaged 22 hr except in

hypothyroid and high thyroxine-binding globulin (TBG) patients where the

equilibration period was delayed by 10 hr. The mean T3 distribution

space in normal subjects was 38.4 liters. This was reduced in subjects

with high TBG levels (26 liters) and increased in patients with low TBG

and in all hyperthyroid states (53-55 liters). The normal serum T3

concentration was estimated by radioimmunoassay to be 0.106 μg/100 ml.

Combined with the mean T3 clearance value of 26.1 liters/day, the

calculated T3 production rate was 27.6 μg/day. The mean T3 production

rate increased to 201 μg/day in thyrotoxic Graves' disease patients and

was reduced to 7.6 μg/day in primary hypothyroid subjects. T3 production

rate was normal in subjects with altered TBG states. The ratio of T3 to

T4 production rate in normal subjects was 0.31 and was unchanged in

patients with altered TBG values. This ratio was increased in all

Graves' disease patients with the highest value being 0.81 in the

posttreatment hypothyroid Graves' disease group. This apparent

preferential production of T3 may have been responsible for the

retention of rapid turnover kinetics for T3 and T4 observed in treated

Graves' disease patients. The finding that factitial thyrotoxic patients

also displayed similar rapid T3 and T4 turnover kinetics indicates that

these alterations are not a unique feature of Graves' disease per se.

When comparing the peripheral turnover values for T3 and T4 in man, it

is apparent that alterations in metabolic status and serum TBG

concentration influence both hormones in a parallel manner; however,

changes in metabolic status seem to have a greater influence on T3

kinetics while alterations in TBG concentrations have a greater effect

on T4. These observations probably relate to the differences in TBG

binding affinity and peripheral tissue distribution of these two hormones.

The following two papers both are both cited for T3 half life, but I

have yet to read them. If I get some time tomorrow, I will try to take a

look. They may cite the earlier studies.

Escobar-Morreale HF, Botella-Carretero JI, Gomez-Bueno M, Galan JM,

Barrios V, Sancho J 2005 Thyroid hormone replacement therapy in primary

hypothyroidism: a randomized trial comparing L-thyroxine plus

liothyronine with L-thyroxine alone. Ann Intern Med 142:412-24

Hennemann G, Docter R, Visser TJ, Postema PT, Krenning EP 2004 Thyroxine

plus low-dose, slow-release triiodothyronine replacement in

hypothyroidism: proof of principle. Thyroid 14:271-5

I suppose if you want to discuss any of these, Sheila would prefer we

take it to the GabLab list.

Chuck