Is Hypothyroidism a complication of diabetes?

Is Hypothyroidism a complication of diabetes?

If I lower my average bg enough, can I reverse this complication? If so what A1C would be the goal? 4.0?

I looked through the DCCT results but didn't see any link between average bg and hypothyroidism. Closest I found was this: Thyroid Dysfunction in Patients With Type 1 Diabetes which seems to be saying there is no link between A1C and hypothyroidism. But very very few DCCT patients had A1C's below 5.0, even in the intensive group, so maybe it wasn't intensive enough.

Any link between carb consumption and hypothyroidism?

I do know that Hashimoto's can be a cause of hypothyroidism. Hashimoto's is an autoimmune condition, and both diabetes and other autoimmune conditions often occur together, a condition called Polyglandular Autoimmune Syndrome.

But does something else besides diabetes or the treatment of diabetes cause hypothyroidism. I've struggled with this question. About a year ago, I started having low body temperature, a classic symptom of hypothyroidism. I did not "test" as hypothyroid, but I am not totally convinced. And when I looked into it, there does appear to be some argument that low carb diets can cause a downregulation of your thyroid function. Jenny over at bloodsugar 101 believes that low carb diets downregulates the thyroid. She suggests that it affects long term low carbers and you should avoid it by keeping above the ketogenic boundary. I am not so sure.

My understanding is that most "hypothyroidism" in T1 diabetics is the result of Hashimoto's Thyroiditis, which is an autoimmune condition just like T1D. People with 1 autoimmune disorder are always at risk for other autoimmune conditions. In this case, hypothyroidism isn't a complication, but a related condition.

Yes, many endocrinologists will test someone with T1D for other autoimmune diseases, like Hashimoto's and like Celiac disease. These are not complications of diabetes, but rather diabetes and these other diseases are all forms of autoimmune diseases - the body attacking it's own cells - and people that have one autoimmune disease frequently have others.

Thanks guys.

I began treatment for hypothyroidism at age 19, about 5 years after I got T1, but I suspect from the way the endos always poked and prodded my thyroid at my checkups, that they suspected it even before then. (This was 30 years ago back when the docs were much more touchy-pokey than lab test centered!)

I've been challenged to find proof that my hypothyroidism wasn't caused by out of control bg's. Also part of that challenge is to "cure my hypothyroidism" which certainly none of my docs have ever implied that I can do.

I know it's always hard to prove a negative.

I personally believe it the way you stated it but other than that one medical paper that didn't find a relation between A1C and hypothyroidism, I don't have much to back me up.

Yeah, see, that's another thing, I don't think I've ever been diagnosed for Hashimoto's. I've just been treated for hypothyroidism for the past 25 years. Maybe I can get an official diagnosis of Hashimoto's through a lab test ... what lab test should I ask my doc for? I get TSH several times a year and have had the other ones run occasionally but I can't even remember their name. I'm not sure what lab test differentiates Hashimoto's from other kinds of hypothyroidism.

That's an interesting argument. That hypothyroidism can be caused by the typical restricted-carb diabetes diet. I hadn't though of that possibility. Certainly 25 years ago I remember one of my endos, told me that maybe insulin use caused hypothyroidism due to "impurities in the insulin", and I hadn't remembered that till now either. (This was pre-DCCT and at least one of my endos back then blamed all diabetes complications on "impurities in the insulin". Stone knives and bearskins!)

Getting back to the "complication or not", if my hypothyroidism was caused by carb restriction, that would sort of make hypothyroidism a side-effect of diabetes treatment. Sort of like the question, is a hypo caused by insulin use, a "side effect of insulin use" or a "complication of diabetes"?

I checked Jenny's website but didn't find her backing up this theory, that carb-restricted diets can induce hypothyroidism, with any medical papers. I will do some googling.

No, thyroid conditions are not complications of diabetes and thus have no relationship between A1C and thyroid. Autoimmune thyroid conditions (which are both hypo and hyper thyroid conditions are comorbid with type 1 Diabetes. People that have one autoimmune condition, seem to be more subject to having other autoimmune conditions and I don't know the science of that. I myself did it the other way around: I had Graves Disease (a hyper thyroid autoimmune condition) 13 years before I was diagnosed with Type 1.

Again, has nothing to do with blood sugars. And as far as I know there is no cure for thyroid conditions, only maintenance.

I am not trying to be a stick in the mud here, but I'm looking for some sort of medical proof that diabetes doesn't cause hypothyroidism.

I personally agree with what you write, it's in agreement with what most all of my docs say, it's just that now that I go look at the medical literature I can't find any proof that high bg's don't cause hypothyroidism.

Of course proving a negative is always hard. The DCCT did good work in showing that retinopathy, kidney disease, etc., are all strongly related to average bg's and some other factors like blood pressure too. That was a huge step forward.

But I'm not sure how to prove that something that is commonly associated with diabetes, wasn't actually caused by the diabetes or high bg's.

The anecdotal fact that I know several folks were diagnosed with hypothyroidism before being diagnosed with diabetes, doesn't help me, because the review board is telling me that maybe they had diabetes or high bg's earlier but it was undiagnosed. I know, always hard to prove a negative.

This is common medical knowledge, that any MD trained in Western medicine should know. The fact that Hashimoto's or Grave's disease are autoimmune disease is understood as is the fact that correcting blood sugars will not alter the the over or under production of thyroid hormones or stop the immune system from attacking the thyroid. What kind of review board is asking for this ? It sounds kinda fishy to me....

As you say, this kind of negative proof is hard to show...like trying to prove the common cold isn't caused by motions of the stars...lol!

Here's another approach ... perhaps you can prove you have an autoimmune thyroid disorder. Some of these can be diagnosed by tests for the auto-antibodies that are attacking the thyroid. For example, Hashimoto's is diagnosed by the anti-TPO antibodies, like T1D can be seen with GAD and Islet cell antibodies. As long as the thyroid is there it will continue to be attacked by the autoantibodies. Would such a diagnosis satisfy this "review board" ?

This is common medical knowledge, that any MD trained in Western medicine should know.

You know I remember 30 years ago, I had several docs tell me that it was "common medical knowledge" that all diabetes complications are caused by impurities in insulin. Of course since then we have the DCCT and other studies that show that many of the complications are caused by high bg's. So maybe that data effectively "proves the negative" by advancing a mechanism backed up by extensive data. Data that has completely redefined diabetes treatment compared to when I was a kid.

I remember when I was a kid, I had some old college geology textbooks my dad got for me at yard sales, that said that the theory of continental drift was a crackpot theory that by common sense couldn't be true. And today? Continental drift is generally accepted as "obvious"... but maybe only because there's so much good data to back it up. Smithsonian: When Continental Drift was Pseudoscience

So to carry the analogy further... maybe the thing that I can prove is that I have Hashimoto's, which is known to be autoimmune caused.

Well, if you believe Lyle McDonald, in "The Ketogenic Diet", pg 47, he writes:

Affecting thyroid levels
A fourth possible mechanism by which ketosis may reduce protein breakdown involves the thyroid hormones, primarily triiodothyronine (T3). T3 is arguably one of the most active hormones in the human body (42-44). While most think of T3 simply as a controller of metabolic rate, it affects just about every tissue of the body including protein synthesis. A decrease in T3 will slow protein synthesis and vice versa. As a side note, this is one reason why low carbohydrate diets are not ideal for individuals wishing to gain muscle tissue: the decrease in T3 will negatively affect protein synthesis.

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