Does Prednisolone affect TSH levels? and What is Central Hypothyroidism?

[Benos123]

Good Morning All,

From 2004 to 2014 my hypo symptoms had been well controlled by thyroxine. However since my then GP retired, his replacement has refused to treat based on symptoms and will only treat based on the specific blood test ranges and which leaves me searching for possible other causes!

Back in 2019, I got Polymyalgia Rheumatica (PMR) and as I have since been taking 5 up to 15mgs of Prednisolone daily, I've now just read a piece on Healthline and which suggested a negative effect of Prednisolone on TSH in relation to Central Hypothyroidism, and which is one I had not heard of before!

And so as one question once again often leads to another, does Prednisolone affect TSH? and what is Central Hypothyroidism?

Kind Regards & Thanks in advance!

[Sleepman]

medscape.com/viewarticle/ab... got this link from a recent post on here and sent it to Mum who had to take the steroid prendisolone for pmr.

It lowers TSH.

I will try to find the post.

I suspect you are on too low a thyroid dose that is causing your pmr .... no evidence just my theory(verging on wild speculation) with Mum.

Her levo dose was reduced based on TSH being low

Her free T3 are 10% which is poor.

She is off the steroid but tebds to need it April May strangely...

[Lottyplum in reply to Sleepman]

In my early 30s (I'm now 75) I was diagnosed with rheumatoid arthritis (in just 1 knuckle joint!). For years didn't know the connection between Hashimotos+rheumatoid arthritis - and the dr@local hospital didn't mention it, or poss didn't know either! When adequately supplemented with Levo, I would have no pain; reduce my Levo (cos of TSH level!)+pain would return!

[Sleepman]

Could not find healthunlocked post which posted this but from the linked article this is the key bit

Medscape: What are some of the reasons for a low TSH level?

Leung: One of the most common situations for a temporarily low TSH level I see is what we call nonthyroidal illness, like a common cold or just being under the weather. Other things that can artifactually lower the TSH level could be the use of steroids, such as prednisone for asthma or some sort of a rheumatologic condition. Also, the TSH level could be low if a person has been recently exposed to very high amounts of iodine, such as iodinated contrast needed for a CT scan.

[SlowDragon Administrator]

Dose is probably 5-15mg (not mcg)

In theory it shouldn’t have much effect on TSH …..but it probably does reduce it somewhat

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

Other posts that mention Prednisolone

healthunlocked.com/search/p...

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test

As I said in your post 2 months ago….

Free T4 (fT4) 17.9 pmol/L (11.9 - 21.6) 61.9%

Free T3 (fT3) 5.13 pmol/L (3.1 - 6.8) 54.9%

These look pretty normal for someone not on replacement thyroid hormone

But prednisolone may be lowering TSH

[humanbean]

what is Central Hypothyroidism?

The most common form of hypothyroidism in the UK, the US, Canada, and several parts of Europe is Primary Hypothyroidism (PH). In PH the problem is with the thyroid, which becomes unable to produce enough thyroid hormones due to damage, usually caused by autoimmune disease. The TSH gets higher in response to the poor output of the thyroid, trying to stimulate the thyroid to produce more hormones.

In Central Hypothyroidism (CH) the thyroid is usually healthy, but it responds poorly because TSH (Thyroid Stimulating Hormone) is in short supply. TSH is produced by the pituitary. And disease or tumours affecting the pituitary can reduce the output of TSH. Another possible reason for the lack of TSH is that the hypothalamus cannot produce sufficient Thyrotropin Releasing Hormone (TRH) to trigger the pituitary to produce TSH. (Thyrotropin is another word for TSH.)

Central Hypothyroidism is actually caused by a problem with the pituitary OR the hypothalamus. When doctors investigate a person with CH they can't know in advance where the problem originates. But when they do find that out, the patient is diagnosed with either :

a) Tertiary Hypothyroidism - hypothalamus doesn't produce enough TRH, so the pituitary is under-stimulated.

b) Secondary Hypothyroidism - pituitary doesn't produce enough TSH, so the thyroid is under-stimulated.

c) Primary Hypothyroidism - thyroid doesn't produce enough thyroid hormones because of under-stimulation by TSH.

In all three cases described above the ultimate result is an under-stimulated thyroid, and the treatment is the same in each case - replacing the missing hormones from the thyroid.

I suspect, in reality, doctors probably continue to use the term CH even when they have found out where the problem originates i.e. either the pituitary or the hypothalamus.

There is another form of hypothyroidism which is caused by a lack of iodine with which to create thyroid hormones. This form of hypothyroidism is most common in Asia. In order to absorb as much iodine from the diet as possible when it is in short supply the thyroid (sometimes) enlarges and swells up to form a goitre.