Thyroid Colloid Nodular Goiter and Hyperthyroidism

[Shroom Man 777]

We're having a case presentation thinggy for our NUERSING and our case is about some dude who's got Thyroid Colloid Nodular Goiter and Hyperthyroidism. We're having some problems though.

One of the predisposing factors for goiter is decreased iodine input. That causes goiter because, as wiki says:

Iodine is necessary for the synthesis of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). In endemic goitre, iodine deficiency leaves the thyroid gland unable to produce its hormones because the hormones are made out of iodine. When levels of thyroid hormones fall, thyrotropin-releasing hormone (TRH) is produced by the hypothalamus. TRH then prompts the pituitary gland to make thyrotropin or thyroid stimulating hormone (TSH), which stimulates the thyroid gland’s production of T4 and T3. It also causes the thyroid gland to grow in size by increasing cell division.

Now we're having a little boggle. Iodine deficiency makes the thyroid gland unable to produce T4 and T3 because they need iodine to be reproduced. So that causes the hypothalamus to produce TRH to stimulate the pituitary gland to make TSH to stimulate the thyroid gland to produce more T4 and T3 - causing the thyroid gland to grow in size.

Increased production of T4 and T3 causes hyperthyroidism by fucking the body's metabolism and stuff up.

But HOW can the thyroid gland produce more T4 and T3 (thus causing the thyroid gland to grow in size or some shit) when iodine is necessary for the synthesis of thyroid hormones thyroxine (T4) and triiodothyronine (T3) and the patient is suffering from iodine deficiency?

It is like asking a factory to build more cars when there's a metal shortage. The factory can't use rocks or wood to make more cars or anything.

Without iodine, how can the thyroid gland make increased T4 and T3 to fuck the body up with hyperthyroidism?

To be or not to be, that is the question.

Goddamn it.

[Shroom Man 777]

Thank you Googel!

Dietary iodine is taken up readily through the gut in the form of iodide. From the circulation, it is concentrated in the thyroid gland by means of an energy-dependent sodium-iodate symporter. In the follicle cells of the thyroid gland, 4 atoms of iodine are incorporated into each molecule of thyroxine (T4) and 3 atoms into each molecule of triiodothyronine (T3). These hormones are essential for neuronal development, sexual development, and growth and for regulating the metabolic rate, body heat, and energy.

When dietary iodine intake is inadequate for thyroid hormone synthesis, the serum T4 level initially falls and a number of processes ensue to restore adequate thyroid hormone production. The pituitary gland senses low levels of circulating T4 and releases more TSH. TSH stimulates the growth and metabolic activity of thyroid follicular cells. TSH stimulates each cell to increase iodine uptake and thyroid hormone synthesis and secretion. Increased TSH levels and reduction of iodine stores within the thyroid result in increased T3 production relative to T4 production. T3 is 20-100 times more biologically active than T4 and requires fewer atoms of iodine for biosynthesis.

These processes tend to conserve iodine stores and help maintain normal thyroid function. In addition, thyroid hormones are deiodinated in the liver, and the iodine is released back into the circulation for reuptake and reuse by the thyroid gland. Even under these circumstances, iodine is passively lost in the urine, with additional small (10%) losses from biliary secretion into the gut.

Therefore, enlargement of the thyroid gland begins as an adaptive process to low iodine intake. Iodine deficiency is the most common cause of goiter in the world. The goiter initially is diffuse but eventually becomes nodular. Some nodules may become autonomous and secrete thyroid hormone regardless of the TSH level. These autonomous nodules have been demonstrated to frequently contain TSH-activating mutations. Initially, thyroid hormone output by the normal thyroid surrounding the autonomous nodules is reduced to maintain euthyroidism. Autonomous nodules may cause hyperthyroidism.

What an ingenius compensatory mechanism!

[Khaat]

The net effect is that the thyroid grows so as not to miss processing what little iodine is in the system. The original compensation mechanism makes sense when the drop in T3 and T4 would be due to insufficient active thyroid tissue to synthesize T3 and T4. Doesn't make sense from a low-iodine diet initiator, unless....

Is this also linked to specific (or non-specific) food craving? If this triggers a hunger for iodine-rich foods in reaction as well, this could result in sublimation and fattening if the diet remains low/insufficient in iodine to deactivate the thyroid growth/hunger.

It is like asking a factory to build more cars when there's a metal shortage. The factory can't use rocks or wood to make more cars or anything.

More asking the factory workers to start scavenging the neighbors' for metal.

[Shroom Man 777]

Doesn't make sense from a low-iodine diet initiator, unless....

Is this also linked to specific (or non-specific) food craving?

Insufficient data on that, I'm afraid.

If this triggers a hunger for iodine-rich foods in reaction as well, this could result in sublimation and fattening if the diet remains low/insufficient in iodine to deactivate the thyroid growth/hunger.

Sublimation? Fattening? You're not supposed to get fat in hyperthyroidism. Please expound further.

More asking the factory workers to start scavenging the neighbors' for metal.

And in return they bring you an entire scrapheap and junkyard's full of content out of scavening the neighbors' houses dry, thus leading to an overabundance of shitty metal and everyone dying of tetanus?

[Dave]

If this triggers a hunger for iodine-rich foods in reaction as well, this could result in sublimation and fattening if the diet remains low/insufficient in iodine to deactivate the thyroid growth/hunger.

Sublimation? Fattening? You're not supposed to get fat in hyperthyroidism. Please expound further.

I think he's expecting "increased consumption of iodine-rich foods" == "increased caloric intake".

[Khaat]

I think he's expecting "increased consumption of iodine-rich foods" == "increased caloric intake".

Yes, I missed communicating my thought accurately: increased food intake in an attempt to get the missing dietary iodine. I should have actually read up first, I apologize.

Major clinical signs include weight loss (often accompanied by an increased appetite), anxiety, intolerance to heat, fatigue, hair loss, weakness, hyperactivity, irritability, apathy, depression, polyuria, polydipsia, delirium, and sweating.

from the wiki, scourge of improper research that it is.

And the resulting goiter being that pile of ("tetanus-bearing") scrap.

[Knife]

And here I was going to go with Hyperthyroidism from a secondary cause (hypothalamus). Cool, though.

[kinnison]

And here I was going to go with Hyperthyroidism from a secondary cause (hypothalamus). Cool, though.

Which may well also happen. I suspect that it is quite possible for the thyroid hormone/TRH/TSH feedback loop to become disconnected - in other words, the hypothalamus carries on making TRH without any negative feedback from the thyroid hormone level, or similarly the pituitary does the same - carries on making TSH without any reference to TRH levels.

Also, I suspect that if this does happen - and it probably does; most things that are possible in the body happen in someone - it is often due to a tumour (benign or otherwise) in either of those two areas, particularly the pituitary.

[Shroom Man 777]

More often than not, it's the pituitary gland that causes all sorts of interesting hormonal abnormalities in the body. See gigantism and dwarfism. It's bad since the pituitary gland not only controls the thyroid, but a whole load of other endocrine glands also, so the effects are pretty broad.

[Knife]

More often than not, it's the pituitary gland that causes all sorts of interesting hormonal abnormalities in the body. See gigantism and dwarfism. It's bad since the pituitary gland not only controls the thyroid, but a whole load of other endocrine glands also, so the effects are pretty broad.

That's actually the bitch about secondary causes, instead of the easy answer of the gland itself being fucked up. Is it the Thyroid? The Adenohypophysis? Hypothalamus?

[Shroom Man 777]

You seem pretty knowledgeable. Are you a doctor, man?

[Knife]

You seem pretty knowledgeable. Are you a doctor, man?

Whom, me? Or Kinnison?

If me, I'm going into the same profession you are.

[Shroom Man 777]

Ah, I was asking about you. Cool, you're gonna be a NUERS too! Like me!

*high five*

Now, what about kinnison?

[kinnison]

Me? I have a degree in chemistry (mostly the bio variety) and run what is usually called a "health food shop"; in actuality about 90% supplements and herbals. The latter, I have been doing for a very long time, and I do my best to know what I'm talking about - which not enough people in my profession do.

To all the medical professionals here; I also know enough to know when I am out of my depth and I am honest enough to say so. Again, not enough people in my profession do that, either.

One might be surprised to hear that I am the first port of call for quite a lot of people. As a semi-random example of one of my responses to this, when confronted with someone with probable prostate trouble I say something like this: "Right. There are as far as I know two problems that, at least in the early stages, have virtually identical symptoms and it is impossible to tell without the proper tests which you have. One is usually just an inconvenience - the other can be lethal. Go and see a doctor as soon as possible."

In that case I usually refuse to sell them anything. Is that a responsible enough attitude?

I am not being confrontational here, at least not intentionally.

[Knife]

More often than not, it's the pituitary gland that causes all sorts of interesting hormonal abnormalities in the body. See gigantism and dwarfism. It's bad since the pituitary gland not only controls the thyroid, but a whole load of other endocrine glands also, so the effects are pretty broad.

Oddly enough, we just went over hypo/hyperpituitarism in pathophysiology lately. Anyhoo, hypopituitry problems are virtually moot at this point with hormone replacement treatments, though in very poor countries you'll probably still see it. That said, pituitary dwarfism as shit goes isn't that bad. Normal body proportions, normal intelligence and the sort. Doesn't carry over to hyper pituitary giantism though, that'll fuck you up. Specially after the epiphesyeal plates close.

On a side note, I really need to find an add on to Firefox with medical terminology in the spell check. These types of posts stress my spellcheck out and most of this post is red lined.

[Shroom Man 777]

In that case I usually refuse to sell them anything. Is that a responsible enough attitude?

That's good.

That said, pituitary dwarfism as shit goes isn't that bad. Normal body proportions, normal intelligence and the sort.

Whereas early hypothyroidism can really fuck up a young person's brain development and really cause stunting.