<<Disclaimer: Verify this information before applying it to your situation.>>
Thanks very much for your replies and apologies for not
replying individually.
ORIGINAL EMAIL:
Has anyone had a low T4 level with a normal TSH (so
probably not autoimmune hypothyroidism?), that has resolved
once coeliac has settled down fully?
My T4 is 7 (normal range 8-21) and my TSH is 2.3 (normal
range 0.35 - 3.5). My TTG is 18 (down from 35 three months
ago and 100 at diagnosis in January).
Research so far
I found a study that discovered low thyroxine in children
with coeliac,
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&d
b=pubmed&dopt=Abstract&list_uids=1437793&query_hl=3
This states that "Serum T4 levels were significantly lower
in children with mucous membrane atrophy...(than in)
children (with) normal gut mucous membrane". However, the
thyroid test I had just before diagnosis (when presumably
the damage was much worse than now) came back normal.
I've read about Euthyroid Sick Syndrome
http://www.merck.com/mrkshared/mmanual/section2/chapter8/8c.
jsp, but I doubt coeliac is sever enough an illness for
this to be the cause. However, this may fit with the
children in the study mentioned previously so maybe it's a
possible cause for low T4 in some adult Coeliacs. The main
reason I don't think this is the case with me, is that the
low thyroxine didn't show up in the blood test just before
diagnosis when damage and malabsorption was at its worst,
but has appeared during recovery.
The only other possibility I've seen for these results is
hypopituitarism but this is rare and I don't like the sound
of it! http://www.umm.edu/endocrin/hypopit.htm
My GP has prescribed Levothyroxine at the lowest dose (25
micrograms) to see if it helps with my continued tiredness
with the intention of testing again in three months.
REPLIES:
1. The most likely explanation is that this IS the early
stages of hypothyroidism - partly because you are female
and coeliac, both risk factors. Thyroid disorders are very
common and often underdiagnosed. If you search under
coeliac/celaic and hypothyroidism you will see many links
and some evidence of TSH improving on a GF diet. Look
especially at Ventura's work in Italy. It is also quite
common to be diagnosed with Autoimmune hypothyroidism
(Hashimoto's) AFTER CD diagnosis, even by some years. Have
you been tested for the antibodies? This is important but
may need to be done by an endocrinologist. I had a TSH of
2.9 two years after diagnosis but within 6 months it was
110 (!) although my symptoms were classically non-specific
and seemingly minor: dry skin and hair, lack of interest in
food and drink but not losing weight, tiredness,
irritability (actually I did start to feel very peculiar by
that stage, though not exactly ill). It was difficult to
control for 2 years -even episodes of hyperthyroidism which
is unusual but not unknown ("Hashitoxicosis"). It now
seems stable on a low dose of thyroxine (25 or 50mcg
usually) - rather less than is "normal" sggesting that the
GF diet does indeed allow some recovery of the thyroid. It
may seem confusing to have these problems AFTER going
gluten-free. There is evidence that unfortunately the
tendency to other autoimmune disorders like Hashimoto's is
NOT lost despite a strict diet for some years (unless the
diet is started very early in childhood: this does seem to
be protective). Incidentally although your TSH is "normal"
you will find plenty of mainly anecdotal evidence that
coeliacs (and others) at any rate are very sensitive to
small variations and GENERALLY fell best when their TSH is
UNDER 2. I would say about .75 is my ideal! So it is not
unreasonable for your doctor to prescribe a small dose of
thyroxine to see how you feel and if yout T4 improves (you
have no doubt already found from the many thyroid websites
that treatment of "subclinical hyporthyrodism" may be
helpful longterm). Anyway my understanding from my
endocrinologist is that 25mcg this a such small dose it is
not likely to be harmful. Most women feel better on more
thyroxine rather than less - which can be bad for you
(thyrotoxicity over along period damages your bones apart
form anything else, which obviously coelaics want to avoid)
hence the doctors caution, but really so long as you have
regular checks this is not an issue. I did a lot of
research on this and my impression is that, if this is the
start of Hashimoto's, it may take a while to settle; that
TSH levels can change quite suddenly; that a strict gluten-
free diet may so be "helpful" and MAY slow, but will not
ultimately prevent, the gradual loss of thyroid function
over the years; and that thyroxine medication is very
effective and safe (a pure hormone with no side effects)
taken under supervision with regular checks. If your
concerns continue it might be worth seeing an
endocrinologist, though it sounds as if your GP is at being
helpful and open-minded.
2. Although you are in the "normal" range for TSH, this
range is continually changing as doctors learn more. A few
years ago it the normal range went up to 5.5. Doctors now
aim for a TSH of 1.0. So for you, perhaps it is too high.
I'm hypothyroid, and felt sick still at 2.3, and recovered
at 1.0. My TSH went as high as 49.8 at its worst.
3. If you suspect hypopituitarism, you would have to have a
growth hormone stimulation test, and other endocrine work
up to define that. There are only a few places in the
country that do that as a package deal.
4. I'd want to know my free T3 level in addition to the
free T4 and TSH. T3 is the active hormone, converted from
T4. Some people have good free T3 despite low free T4,
indicating that they convert well. But if both T3 & T4 are
low, it is a stronger signal for the potential helpfulness
of T4 supplementation.
Regards autoimmune thyroid issues, the most direct test is
for the actual antibodies (2 or 3 tests). If those are
elevated, then an autoimmune reaction is at work.
5. An optimal TSH is about 1. So your TSH of 2.3 is a bit
on the hypo side. Still in normal range, but not ideal.
With a little Levothyroxine, your TSH will decrease and
your T4 will come up some to normal range.
A free-T4 is more meaningful than T4. My endocrinologist
always checks TSH and free-T4. Free-T3 should be run
ideally, but doctors don't seem to check that.
You also may feel more hypo if your body doesn't convert T4
to T3 very well. I have this problem and take Armour
thyroid. I had radiation for Grave's Disease 10 years ago,
hence the need for lifetime thyroid medication. But after
18 months of being gluten-free, I need less thyroid
medication which is an encouraging sign.
Check out thyroid.about.com.
*Support summarization of posts, reply to the SENDER not the Celiac List*
|
