Hyperglycemia from levothyroxine : Has anyone had... - Thyroid UK

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Hyperglycemia from levothyroxine

Dryski profile image
47 Replies

Has anyone had success coming off of levothyroxine after many years? Does the thyroid function come back around on its own? Can blood sugar be improved by stopping the levothyroxine?

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Dryski profile image
Dryski
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47 Replies
greygoose profile image
greygoose

I don't know anything about blood sugar but I do wonder why you think you can come off thyroid hormone replacement.

If your thyroid function was bad enough that you were prescribed it in the first place, it's not going to be any better now. If you stop the levo, thyroid function should return eventually, but the output will only be the same as it was before you started the levo - i.e. inadequate for good health.

Thyroid hormone replacement is for life because hypothyroidism is for life. The thyroid cannot regenerate or repair itself and levo is not a cure for anything. It just replaces the hormone your thyroid can no-long make enough of. :)

tattybogle profile image
tattybogle

depends how knackered the thyroid gland is ..

assuming autoimmune damage to thyroid was the cause of the hypothyroidism and the original diagnosis was sound (repeated high TSH ... lowering fT4 levels ... positive TPOab / and or TGab :

If it's only partly knackered and you stop Levo >>> T4 falls >>> TSH rises >>> high TSH stimulates thyroid to try and make 'however much T4 it's capable of'..... however assuming diagnosis was correct in the first place ... it's not likely to be enough T4 .... so you'd eventually end up with the same symptoms that led you to be on levo in the first place ... and need to start taking it again. Also bear in mind that during the gap between stopping levo and TSH rising enough to try and stimulate thyroid.... you may have a period of 'nowhere near enough T4' which would probably be pretty unpleasant ... so this is an experiment that is likely to make you pretty unwell ..and may take many months to recover from even once you restart Levo.

If thyroid gland is more knackered.... then the thyroid won't be able to produce much /any T4 no matter how high TSH gets or how long you wait ... you'll just go very hypo.

There are other causes of becoming hypo and some of these can be temporary and don't always damage the gland itself .. so if the hypothyroidism was caused by one of those rather than autoimmune hypo . then it's possible the thyroid is still capable of making enough T4 (as long as the original problem has gone away)... so sometimes for some patients it can be sensible to very carefully try coming off levo .

i don't know the answer to the blood sugar bit .

FallingInReverse profile image
FallingInReverse in reply to tattybogle

I am watching this topic closely across various posts when touched upon:

Can a thyroid return to pre-Levo levels after any amount of time on Levo.

FroM the various papers and posts I have read, the answer is a resounding “it SHOULD.”

But Ive seen no paper and no person on this forum that is more conclusive.

My reason for asking is my 17 year old with ambiguous thyroid numbers - free Ts low enough to feel crap, TSH in the high 2s last checked (maybe 3?), NO ANTIBODIES at this point, iron anemic. Finishing her school year before going to university in fall and soooo tired etc etc.

I could put her on Levo right now if I wanted to. And I almost did with that idea that once she got through this high stress school transition phase she could just wean off and see if she actually needs it for life.

But those here told me to wait, get her vitamins up, give her thyroid the environment where it stands a chance.

As I noted in a previous post - asking “if you were me, and my daughter was your own, what would you do.” I feel the answer depends on this question - will the pituitary and thyroid pick up where it left off.

tattybogle profile image
tattybogle in reply to FallingInReverse

speaking as the mother of a nearly 26 yr old daughter ... that thing you are expecting to happen .. ie. a less stressful period later on where she has time and space to try coming off again ........ might not happen.

FallingInReverse profile image
FallingInReverse in reply to tattybogle

Agree on that, that’s the life of a girl-mom and a mom of a teenager : ) What a roller coaster I’m surprised any of us got through it lol.

Still lynchpins on whether there is anything more conclusive on if the pituitary and thyroid can “wake up” after [any duration] of Levo.

She will have bloods probably in a month - have been working on her iron/ferritin, added magnesium, added B12, b complex next.

Also getting her an ultrasound next week for good measure.

All the while she is headaches/fatigue constantly. Of course kids nowadays are overworked and school starts too early for most of them. So of course that plays in. But I observe and she unprompted complains of things so familar to me. So I’m aware there is confirmation bias on my part. But at some point I’m looking for that definitive reason to start Levo… or not. I think a lot will hang on what her TSH does. It’s been climbing for a year now.

tattybogle profile image
tattybogle in reply to FallingInReverse

The more evidence you have gathered about what the thyroid is doing before starting levo the better .... i know it seems cruel to 'watch and wait' .. but anyone who starts self treating without a clear diagnosis is in for quite a lot of grief from doctors going forwards if they do decide to stay on it .... not to mention the constant uncertainty about 'do i even need to be on it anyway' ... the way i look at it is this ... once we start levo we are exchanging our 'variable' T3 production , the ability of the thyroid to vary what is produced in response to everyday / seasonal / stressful stuff / illness etc .. and exchanging it for a very inflexible 'same dose T4 every day and not much T3 ' policy.

The usual result of levo replacement is lower T3 than you had before (and higher T4) .

Personally i'd wait until i had much clearer evidence of hypothyroidism.. ie. a long term pattern of TSH rising and / or fT4 falling / or some evidence that the thyroid gland has damage .. or is unusually small etc .... and to be absolutely certain that everything else had been optimised first ... not because i think the pituitary or thyroid won't start functioning again off levo ... i'm about 80% sure they would .... but because of how many other issues there ... finding the right dose can take months /years of not functioning well .. and coming off could also take months of not functioning well before the pituitary / thyroid woke up and got their act together again .

FallingInReverse profile image
FallingInReverse in reply to tattybogle

Best answer ever.

Yes, so hard to wait.

Also - the benefits of variable T3 production.

She’s 17. It’s killing me to know so much about thyroid and watch her struggle, but once again this forum is so good at “talking me off the ledge.”

Patience patience. Thank you very much!

Dryski profile image
Dryski in reply to tattybogle

This has all been done under doctors care. I was just asking if anyone else has had success coming off of it after a long time.

greygoose profile image
greygoose in reply to FallingInReverse

Can a thyroid return to pre-Levo levels after any amount of time on Levo.

Well, to be perfectly honest, mine was worse! I was on T3 mono-therapy, became very ill with 'something else' and stopped my T3 for six months. When I didn't notice any difference, I became convinced I'd been misdiagnosed until, after six months, I started to put on weight very rapidly. And I had been very thin up until then. Got tested and my TSH was about 45. It had only been 11 when I was diagnosed, but as I have Hashi's, that doesn't mean much. But my FT4 and FT3 were very low - lower than at diagnosis - almost none existant. BUT, my thyroid was working again, even after a good ten years of a suppressed TSH. So, I imagine that during the time I'd been taking thyroid hormone replacement, the Hashi's had been going about its business, and I didn't have very much thyroid left. BUT, it was doing its best!

Obviously, I had to go back on T3 again, and the weight-gain slowed down. Not sure if you call that 'anacdotal evidence', but that's what happened to me. How it would work with Seconday Hypo, I don't know. Depends what state the pituitary is in at the time of coming off levo. But I can't imagine it would have improved fuction.

Dryski profile image
Dryski in reply to tattybogle

Thanks. About fifteen years ago I was told it was secondary hypothyroidism from my pituitary. After all this time it's now being labeled as subclinical. My latest a1c shows sugar is climbing. Just recently became aware that levothyroxine itself can raise blood sugar and I'm very upset that this was never discussed before. I have an endo appointment coming up and hoping things can get reversed somehow.

tattybogle profile image
tattybogle in reply to Dryski

ok, but do you understand that 'subclinical ' isn't a diagnosis, or a cause ?

the term subclinical just means 'TSH is out of range but the thyroid hormones(T4) are still within range'

subclinical hypo means TSH over range with T4 in range

subclinical hyper means TSH below range with T4 in range.

Dryski profile image
Dryski in reply to tattybogle

Mine is subclinical hypothyroidism now. Hoping endo can clear up if it still has a pituitary component or never did. Mistakes happen.

tattybogle profile image
tattybogle in reply to Dryski

The use of terminology on medical records by medics when describing thyroid conditions is often wooly / vague / just plain inaccurate ..... and mistakes happen on records all the time especially when they are updated .... i recently found post natal depression dated the year BEFORE i had a baby is on my record, seems to have been put there when they were changed to digital from paper~ wrong date , and never had post natal depression , but did have a counselling appointment for something else ...... so do bear in mind that just because someone has written subclinical hypo on your notes .. it really does not mean anyone has given it ANY intelligent thought ,... it is more likely to just be a mistake by someone who didn't have time to go poking back through your record to see what your original hypothyroidism diagnosis really was and didn't care.

Did you have below range TSH with below range T4 at diagnosis ?... or normal TSH / below range T4..... either of those are clearly secondary hypo.

If secondary was diagnosed when T4 was low but still in range , then it does get a bit wooly and is hard to know how it might be described on records.

if TSH was over range and T4 was in range at diagnosis ......then it's clearly subclinical hypo.

p.s that earlier reply about self treating was to fallinginreverse.. i wasn't saying you had started self treating without medical advice .,, sorry , got carried away talking to someone else on your post. x

FallingInReverse profile image
FallingInReverse in reply to Dryski

Hi there, curious what you e seen that Levo raises blood sugar.

Logically it would seem that Levo helps correct low metabolism issues related to thyroid, which would seem to have the opposite effect on blood sugar.

I have a history (family and personally) with diabetes-related issues. I am always curious how it’s not discussed often here, among us problem hypo people. I have actively noticed that diabetes related symptoms when raised on this board never find that cohort of people responding saying “me too”!

Whereas thyroid is metabolism related, as diabetes is too of course, I have found very little interaction between the two.

But I have not deep dived on this and am always looking for information.

What did you hear or read about the Levo and blood sugar connection?

Dryski profile image
Dryski in reply to FallingInReverse

It's a warning on my patient information directly from my pharmacy. Of course internet has many things can believe or not but this was from my pharmacy with my generic synthroid.

FallingInReverse profile image
FallingInReverse in reply to Dryski

What does it say ?

Dryski profile image
Dryski in reply to FallingInReverse

This drug may affect blood sugar control. Have labs checked often. If diabetic medications may need to be adjusted accordingly. This leaflet was to cover euthrox, levoxyl, synthroid and unithroid. All american brands of levothyroxine.

SlowDragon profile image
SlowDragonAdministrator in reply to Dryski

I think it means the reverse to how you are reading it

When hypo blood sugar control is frequently poor and high HBA1C

As we start on Levo and slowly increase dose to optimal blood sugar control improves

If someone is diabetic before starting on levothyroxine they are likely to need levels checked regularly as blood sugar control improves

ncbi.nlm.nih.gov/pmc/articl....

Baseline HbA1c levels were found to be significantly higher in hypothyroid patients compared to control individuals despite similar glucose levels. HbA1c reduced significantly with treatment in hypothyroid patients without a significant change in glucose levels.

thyroid.org/patient-thyroid...

This study suggests that hypothyroidism may be falsely increasing the levels of the HBA1C test. While thyroid hormone therapy decreases the HBA1C test results, suggesting an improvement of blood sugar control, actual measurements of fasting blood sugars and overall glucose tolerance were unchanged on thyroid hormone therapy. This may lead to errors in diagnosing pre diabetes and diabetes in patients with hypothyroidism. This is important for both physicians and patients to know.

Dryski profile image
Dryski in reply to SlowDragon

They are going by the standard HBA1C and trying to label diabetes when my fasting blood sugars are fine. Just like that says it leads to errors and upsetting people with pre diabetes which I call crap anyway and putting this on my record.

Bertwills profile image
Bertwills in reply to Dryski

I’ve been having trouble with HbA1c tests. Are you eating low carb? I was for 5 months and my HbA1c test numbers rose rapidly. Apparently it can do this to some people. Maybe being hypo increases the likelihood. I’ve stopped eating that way now & will see in 2 more months if there’s been an improvement.

FallingInReverse profile image
FallingInReverse in reply to Dryski

Great links from SD- and I just dug in a little and see lots of factors from increased glucose to insulin resistance.

But it can mean blood sugar goes up, or down, and from what I see also has to do with pre existing conditions, and the outcome is not to stop Levo, rather to adjust your glucose management.

If I were you I would manage your thyroid properly… and not use the glucose as a reason to stop Levo.

If you were improperly diagnosed and improperly given Levo (I’m not sure I haven’t looked back at your posts), then test that head on and methodically.

There is a bias on this forum from many personal experiences of watching people look for reasons to stop taking Levo. We will never know about those who do with success and never find the forum. That being said - Having a functioning thyroid is the only reason someone should ever go off hormone replacement.

So if you have reason to believe you have a functioning thyroid - then that’s what to try to prove. The blood glucose is either a diabetes red flag or a red herring.

All above my opinion, don’t know your history and am always learning new things.

radd profile image
radd in reply to Dryski

Dryski,

Levothroxine should encourage good use of the hormones involved with blood glucose metabolism. However, the introduction of Levothyroxine will speed up metabolism and should there be an underlying blood glucose issue, it may be suddenly disclosed leading to misinterpretation of Levo directly inducing blood glucose issues.

Jazzw profile image
Jazzw in reply to Dryski

I’m intrigued as to why a doctor would decide that secondary hypothyroidism was misdiagnosed. In your position I would ask for a full print off of my blood test results from back then. Most doctors are very reluctant to even consider the possibility of secondary hypothyroidism, so it’s not unlikely that you had a good doctor back then who thought outside the box—and that you now have a not so great doctor who doesn’t understand secondary hypothyroidism at all.

Regarding blood sugar, I’m not sure why you’re worried. Do you already have diabetes?

Dryski profile image
Dryski in reply to Jazzw

I had an excellent doctor back then and if he wasn't retired I still would have. I've have several GP since then who just followed suit. My a1c levels have only recently been going up because of the higher dose of levo. They are trying to label me diabetic but still on the line. I'm hoping to stall or reverse this in all ways. My older doctor did most charting by hand back then but I have copies of my scan reports showing microadenoma just nothing on labs. I never asked questions back then or kept copies.

Jazzw profile image
Jazzw in reply to Dryski

Sounds like it could well be secondary hypothyroidism. The trouble is, there’s no easy way of being able to establish which kind of hypothyroidism you have from blood tests when you’re on thyroid replacement medication. And stopping medication after all these years could make you very ill indeed. What tends to happen is that people actually feel loads better when they first stop taking it… many have been hoodwinked into thinking, gosh, I never actually needed levothyroxine! And then a few months later, nosedive into absolute health chaos as thyroid hormone levels drop through the floor. It can take months and years to recover from that. Having a slightly elevated HBA1C would be the least of your worries.

If you’re heading into the prediabetic range, cutting carbohydrate intake and/or losing some weight (even if you’re quite slim) is probably the most effective way of reducing HBA1C. You don’t necessarily need to go full on keto (with thyroid issues I personally wouldn’t recommend it anyway, as converting T4 to T3 appears to need some carbohydrate intake) but dropping carbs to 50-100g a day would probably have a significant impact.

You’ve mentioned fasting—what sort of fasting have you been trying?

HealthStarDust profile image
HealthStarDust

This is something I think about often. That is, can my thyroid bounce back to prediagnosis state given that I am having an awful time on just levothyroxine?

I feel like the world has played a cruel joke on me as I doubt I would have persevered with levo were it not for the fact that I wish to have a baby. And, now I am too scared to come off it!

No answers I’m afraid, except despite research and anecdotal evidence of what may happen if someone stops taking their levothyroxine, realistically there’s only way to find out how it’ll affect you.

They may not exist on this forum (why would they?!) but people do stop taking levothryoxine. Everyone is different. Hey, sometimes I wonder if we only need the hormone replacement short term to wake up our body in some way to do what it should have been doing in the first place.

Dryski profile image
Dryski in reply to HealthStarDust

I don't know either but I'm a mission to see if mine can be discontinued under doctors care of course. I think everyone is different and each situation may need different help.

HealthStarDust profile image
HealthStarDust in reply to Dryski

Agreed. I hope you let us know how you get on.

Dryski profile image
Dryski in reply to HealthStarDust

Just letting you know my gp agreed to let me stop the levo till I see an endo in two months. Fingers crossed my thyroid can still fly on its own.

HealthStarDust profile image
HealthStarDust in reply to Dryski

Thank you for sharing.

I think you know that your GP does not have to ‘agree’ with you to stop taking a prescription drug in order for you to stop. So, I hope it’s more of a case of have your GP on board with your plan.

Just wondering… if it is the levothyroxine causing your body bother, have you thought maybe switching brands or preparation can help? Sometimes that’s all it takes. It’s worth exploring.

I have my fingers crossed for you.

Jazzw profile image
Jazzw in reply to Dryski

If the cause of your issues was pituitary then your thyroid won’t be prompted to fly on its own.

Elayda profile image
Elayda

I was on it for a decade and weaned off it about 10 years ago. My thyroid function tests come back normal. Dont know about the blood sugar.

Dryski profile image
Dryski in reply to Elayda

Glad it worked for you. I'm hoping for the same.

Sparklingsunshine profile image
Sparklingsunshine in reply to Dryski

Like many, (maybe all of us) I've wondered how much thyroid function I have left, I've never had raised antibodies and had them tested both privately and on NHS, I think my pituitary got damaged during childbirth as I had a massive haemorrage, as I was on blood thinners during my pregnancy.

So I dropped my Levo dose massively last autumn, my surgery were whinging about the annual thyroid test and not wanting them to freak out at my very low TSH I decided to cut right back on Levo. I dropped down to 50mcg from 150mcg and left it off altogether for a few days. The result was my TSH had risen a bit, 0.33, range 0.27 - 4.2, but the real eye opener was FT4 was only 7 range 12-22 and FT3 was 2.7 range 3.1 to 6.8.

It was weird that the TSH wasnt reflecting the terrible low frees I had, I actually got an increase in Levo lol, to 200mcg a day but this was the time I decided to self source and add some T3.

It certainly confirmed that irrespective of the cause of my hypo, my thyroid function is fully dependent on external thyroid meds now. Its clear my thyroid isnt performing normally anymore. I've only been on thyroid replacement for nearly 4 years so I'm by no means a long term user.

HealthStarDust profile image
HealthStarDust in reply to Sparklingsunshine

Sometimes I wonder if our bodies become dependent on it once we start taking it.

HealthStarDust profile image
HealthStarDust in reply to Elayda

Are you still off it?

Are you taking any other hormone replacement like NDT?

How long did it take to wean off?

How big or small was each reduction?

So many questions as we never hear from people on this forum who have come off levothyroxine and remained off it.

Curious.

Dryski profile image
Dryski in reply to HealthStarDust

Just stopped four days ago with doctors permission. Not on other replacement. From 125 to 0. I feel better already but have no idea what the future holds. I have an endo appointment in two months. Hoping my A1c levels will improve being free of levo. A girl can hope.

HealthStarDust profile image
HealthStarDust in reply to Dryski

Keep us posted. And, I hope the endo appointment is a success.

Elayda profile image
Elayda in reply to HealthStarDust

Yes I am still off it.

No not taking any hormone replacements.

I used to take one a day (can't remember the dosage).

Then I dropped down to 5 a week for about 3 months, then 3 a week for 2 months then 1 a week for another 2 months.

I went really slowly because my symptoms were pretty bad when I was first diagnosed and I didn't want to end up back there.

I hope this helps:)

HealthStarDust profile image
HealthStarDust in reply to Elayda

It sure does. Thank you.

So you stayed on the same dose throughout, just dropped some days as you went along?

Elayda profile image
Elayda in reply to HealthStarDust

Yes that's right

HealthStarDust profile image
HealthStarDust in reply to Elayda

It’s interesting. A while ago I read somewhere (I can’t remember where) that it’s better to stop it all at once so your thyroid has more of a chance to bounce back. I’m not sure why. I didn’t understand the science.

I take it you feel better without it?

Elayda profile image
Elayda in reply to HealthStarDust

Hmm I hadn't heard that. Perhaps it would have been fine if I had just gone cold turkey.

I feel the same with or without them. So, I don't see the need in taking them.

HealthStarDust profile image
HealthStarDust in reply to Elayda

Thank you so much for sharing your experience with me.

Elayda profile image
Elayda

No problem 😃 I hope things work out for you too.

Sunflower64 profile image
Sunflower64

As for coming off thyroid hormone replacement, others have already given you good advice. As for the levo/blood sugar connection, the late US thyroid expert Kenneth Blanchard said thyroid thyroid hormone should be taken with food to avoid insulin resistance and cravings.

Dryski profile image
Dryski in reply to Sunflower64

Very interesting. See what my endo says about that if they put me back on it. Thanks.

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