Thyroid UK
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Why do we get myxoedema?

Why do we get myxoedema?

First, by myxoedema I am specifically meaning the swelling so strongly associated with hypothyroidism - the non-pitting oedema which affects so many.

Second, this is simply one new paper announcing their specific findings. It does not mean it is the only reason.

As I read it, the paper says that proper levels of T3 result in the production of hyaluronic acid slowing down and everything being good. But with low levels of T3, the body keeps making hyaluronic acid even when there is already plenty. So it collects and causes the swelling. Hyaluronic acid manages to cause the retention of large amounts of water.

If correct, it is interesting that this is a very specific T3 function.

In Vitro Cell Dev Biol Anim. 2013 Feb 9. [Epub ahead of print]

Triiodothyronine (T3) inhibits hyaluronate synthesis in a human dermal equivalent by downregulation of HAS2.

Pouyani T, Sadaka BH, Papp S, Schaffer L.


Department of Pharmaceutical Sciences, Northeastern University, Bouvé College of Health Sciences, Boston, MA, 02115, USA,


Triiodothyronine (T3) is a thyroid hormone that can have varying effects on skin. In order to assess the effects of T3 on the human dermis, we prepared dermal equivalents using neonatal dermal cells via the process of self-assembly in the presence of differing concentrations of T3. These dermal equivalents were prepared in the absence of serum and a three dimensional matrix allowing for the direct assessment of different concentrations of T3 on dermal extracellular matrix formation. Three different concentrations of T3 were chosen, 20 pM, which is part of the base medium, 0.2 nM T3 and 2 nM T3. We find that self-assembled dermal equivalents formed under these conditions show a progressive "thinning" with increasing T3 concentrations. While we observed no change in total collagen content, inhibition of hyaluronate (HA) synthesis was observed in the 0.2- and 2-nM T3 constructs as compared to the 20-pM construct. Other glycosaminoglycan synthesis was not affected by increasing T3 concentrations. In order to identify the gene(s) responsible for inhibition of HA synthesis in the 2-nM T3 dermal equivalent, we conducted a differential gene array analysis. The results of these experiments demonstrate the differential expression of 40 genes, of these, 34 were upregulated and 6 genes were downregulated. The results from these experiments suggest that downregulation of HAS2 may be responsible for inhibition of hyaluronate synthesis in the self-assembled 2-nM T3 human dermal matrix.

PMID: 23397370 [PubMed - as supplied by publisher]


The picture is of Chinese Shar-Pei dogs - seems their characteristic wrinkled skin collects hyaluronic acid which forms "socks". Also the meatmouth Shar-Pei (A–C) is predisposed to a breed-specific periodic fever syndrome called Familial Shar-Pei Fever (FSF). Well I never...

6 Replies

Interesting info. I was rather hoping that my swelling would go now I'm getting some T3 but I suppose it will just take time :/


Have been on Armour for a year now so getting some T3 but only just reached a reasonable dose due to variety of problems. At last my huge tongue is reducing and I no longer have to sleep with it lolling out of my mouth like a rabid dog! Hands and legs/feet reducing too very slowly but sadly not the belly yet! Hope yours doesnt take so long.


Thanks. That is reassuring to hear. I don't know if I am on the right dose yet. I could increase again this week (4 weeks since last increase) but that would take me to 4 grains which feels like an awful lot for someone who was on 125mcg levo.

I might try an increase soon but I'm already starting to feel a lot better. Even my sensei has noticed an improvement. I get through a lesson without feeling like I need an ambulance and I can remember stuff and move without feeling like an 80 year-old!

I suppose I can always reduce the dose back down if it feels like too much :)


Hi Carolyn,

I was on 7 grains armour from the thyroid doctor I saw, absorption problem and very low FT3. When I saw my endo, years ago now, She sorted out the absorption, long story but I now have pancreatic enzymes and reduced my armour, a lot.The T3 became available. I now take 2 and a half grains and 20mcg T3. T4 and FT3 have always been in range, on treatment,T3 high in range which I need. TSH has always been unmeasurable, but no cause ever found.

Best wishes,



When I last saw Dr S he said that most people need between 3 and 4 grains but some as much as 5. He did also say it can take 6 months or more for all symptoms to improve though I have been very ill with calcium problems as well. I tried to increase to 3 and three quarter grains but knew very quickly that it was too much though that was 10 weeks ago so thinking I may need to increase again now as some things worsening. I guess its just knowing your own symptoms.


Dr. Barnes observed that the two most common symptoms he saw in patients on T4 only who were still having problems were dry skin and/or fluid retention. He even wrote a short paper about this fact. It is good they are beginning to understand the underlying chemistry. Thanks for the article. PR


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