FW: [TPAWorkingParty] Check this out......

[Guest guest]

From .

HI

Here is a study abstract done by NIH:

http://jcem.endojournals.org/content/early/2011/08/17/jc.2011-1329.abstract

Abstract

Context: Levothyroxine (l-T4) therapy is based on the assumption that the

conversion of T4 into T3 provides adequate amounts of active hormone at target

tissues. However, in rodents, l-T4 alone does not restore a euthyroid state in

all tissues. Previous combination l-T4/liothyronine (l-T3) therapy trials

focused on quality-of-life endpoints, and limited information is available on

the effects on other measures of thyroid hormone action.

Objective: Our objective was to evaluate the efficacy of thyroid hormone

replacement with l-T4 or l-T3 at doses producing equivalent normalization of TSH.

Participants, Design, and Setting: Fourteen hypothyroid patients participated

in this randomized, double-blind, crossover intervention at the National

Institutes of Health Clinical Center.

Interventions: l-T3 or l-T4 were administered thrice daily to achieve a target

TSH from 0.5–1.5 mU/liter. Volunteers were studied as inpatients after 6

wk on a stable dose and at the target TSH.

Main Outcome Measures: Serum thyroid hormones, lipid parameters, and indices of

glucose metabolism were evaluated.

Results: No difference was observed in TSH between l-T3 and l-T4 treatments.

l-T3 resulted in significant weight loss [l-T4, 70.6 ± 12.5, vs. l-T3, 68.5 ±

11.9 kg (P = 0.009)] and in a 10.9 ± 10.0% decrease in total cholesterol (P =

0.002), 13.3 ± 12.1% decrease in low-density lipoprotein-cholesterol (P =

0.002), and an 18.3 ± 28.6% decrease in apolipoprotein B (P = 0.018). No

significant differences were observed in high-density lipoprotein-cholesterol,

heart rate, blood pressure, exercise tolerance, or insulin sensitivity.

Conclusions: The substitution of l-T3 for l-T4 at equivalent doses (relative to

the pituitary) reduced body weight and resulted in greater thyroid hormone

action on the lipid metabolism, without detected differences in cardiovascular

function or insulin sensitivity.

* * * * * *

Please take particular note of the first sentence: Levothyroxine (l-T4) therapy

is based on the assumption that the conversion of T4 into T3 provides adequate

amounts of active hormone at target tissues.

This is the assumption that the American Thyroid Association believes applies

to everyone at all times. I.e., it never fails or becomes deficient.

I requested a copy from Dr. Celi.....

Have a great day,

[Guest guest]

forwarded this to the main thyroid group Tony, as this topic is

nothing to do with the Working Party forum.

Luv - Sheila

What puzzles me about this work is that the combined therapy people lost a

substantial amount of weight even though their TSH was maintained in range. My

wife takes 30 to 40 mcg of T3 a day which results in a suppressed TSH but no

real weight loss even though she is trying to get her weight down. In other

words, compared with the participants in this study, she is taking a

significantly larger proportion of T3 but doesn't get the weight loss effect.

What gives here?

Should she take more T3? I don't think so because her T3 is

already suppressed and if she increases her T3 beyond 40 to 60 or 70 (which she

does occasionally when faced with a particularly demanding time ahead) then her

pulse rate rises to 100+.

Tony

On Sun, Dec 11, 2011 at 11:55 PM, ekp290340 <eric@...> wrote:

HI

Here is a study abstract done by NIH:

http://jcem.endojournals.org/content/early/2011/08/17/jc.2011-1329.abstract

[Guest guest]

Forwarded to keep this on topic on the main thyroid forum.

Luv - Sheila

Rereading the abstract it looks like the T4 was totally replaced by T3, not

just partially. My wife had been on 50T4/30T3 for some time but when she tried

reducing the T4 to 25 and the T3 to 40, she didn't feel too good so reverted to

50T4/30T3 after a week. So, if the patients in the Celi et al report changed

from T4 only to T3 only, based on my wife's experience I would have expected

them to feel unwell fairly soon after the change was made.

Tony

HI

Here is a study abstract done by NIH:

http://jcem.endojournals.org/content/early/2011/08/17/jc.2011-1329.abstract