Short Synacthen Test

[walkes1]

Hi,

Had my Short Synacthen Test results back - base 143 then 30 mins post 608. Apparently all fine, I thought the base was low? Would like some advise please.

The test was done at 11.00.

Thanks in advance

[MaisieGray]

The test evaluates the ability of the adrenal cortex to produce cortisol after stimulation by synthetic ACTH, and adrenal insufficiency is excluded when there is an incremental rise in cortisol of > 200 nmol/L and a 30 min value > 600 nmol/L. Hence your results being deemed fine. It's not a test of general cortisol level(s) - you'd need a four point saliva test for that.

[radd]

walkes1,

Doctors do not recognise the importance of the circadian pattern that cortisol levels should naturally follow.

These levels commonly go askew in people with low thyroid hormone. Your test only discloses a possible low 11am cortisol level that includes both bound and unbound, and an adrenal gland response to the synacthen.

To investigate cortisol levels further, you will need to perform a 24 hour saliva stress test that measures only the free cortisol (that is available for use) and DHEA levels.

[Ginny52 in reply to radd]

What does very low salivary dhea mean? Thanks, ginny

[radd in reply to Ginny52]

Ginny,

DHEA and cortisol are antagonistic to each other & need to be in proper balance for optimal health.

Adequate DHEA is vital for conversion to oestrogen and testosterone but levels commonly become low as cortisol becomes elevated in response to low thyroid hormone.

[PiggySue]

To get a proper result the test should have been done at 8 or 9am, but it is really difficult to make sure that you get it at that time. My test was at 10.30am. My baseline was not nearly as low as yours (230) but did not rise/stim as much as yours.

What were the numbers that made them run an SST?

I didn't get the ACTH numbers, it seems that they don't test these, and you need them to rule out Secondary Adrenal Insufficiency. It seems that in my area the NHS are only interested in Primary AI/Addison's. However if you have a problem with your thyroid, you would think that they would want to know where in your HPA axis there might be a problem if you have low cortisol as well.

You can get both the SST and the ACTH done privately.

There is a support group on facebook (obvs not as good as here, but more specialised on cortisol issues). UK Addisons disease info & support group.

Are you on T3 only? Paul Robinson has brought out a new book that deals with some of the issues that T3 can affect.

[Hidden]

Did they do an ACTH blood test at the start of the test? it would have needed to go on ice straightaway. Your base cortisol level is low however you stimmed well, this shows that your adrenal glands are working well. The problem could be pituitary related, as your Endo didn't think there was a problem he is obviously not experienced in pituitary/adrenal issues & you need to find one that is. Very few NHS doctors so 24 salival cortisol tests, you need to ask your GP to refer you to an experienced Endo, the Pituitary Foundation will have a list of experienced Endo's so give them a call.

[SlowDragon Administrator]

5 months ago your vitamin levels were low and FT4 and FT3 not high enough

healthunlocked.com/thyroidu...

Have you improved vitamin levels and did you get dose increase in Levothyroxine?

If not retested then suggest you get full Thyroid and vitamin testing privately

[walkes1 in reply to SlowDragon]

Hi, endo started me on T3, and reduced my levo from 100 to 50. Due bloods again next week.

I have recently had a chest CT and respiratory follow up for SOB, (all clear, thankfully). I’m due to have MRI as I have a bulging disc, and due to have a 7 day ECG monitoring for ongoing symptoms. I feel mentally exhausted with it all. I do need to think about vitamin levels.

[SlowDragon Administrator in reply to walkes1]

How much T3 was added?

As single dose or split dose

That's a large reduction in Levothyroxine

When you do blood test next week, It should ideally be done as early as possible in morning and fasting. Do not take Levothyroxine dose in the 24 hours prior to test, delay and take immediately after blood draw. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

When also on T3, make sure to take last dose EXACTLY 12 hours prior to test

My endo only reduced my Levo by 25mcg when 2 x 5mcg T3 was added (more details on my profile)

[walkes1 in reply to SlowDragon]

I am on 20 mcg split 2 x 10, I cut in half rather than crush and dilute as advised by endo, she said the 2nd dose should be ok in the fridge, but she wasn’t convincing enough, the pharmacist gave me a cutter so more reason to to cut in half.

She did say that having the T3 added will compensate the reduction in levo, but again not convincing. Can’t complain, so far she is the only one that has listened.

I will take your advise, thank you

[SlowDragon Administrator in reply to walkes1]

Ok

20mcg is huge dose to start on, but if you’re coping carry on

Most start on 2 x 5mcg

Then increase after 6/8 week blood test

Are you taking 10mcg dose 12 hours apart?

If you eventually want to experiment with 3 doses per day - 8 hours apart. Some of us find that works better (but leave as is until at least after upcoming blood test)

10mcg on waking 5mcg mid afternoon and 5mcg at bedtime (each dose is 8 hours apart)

Your FT4 might have dropped too low on just 50mcg

Come back with new post once you get results

Last dose Levo 24 hours before blood test

Last dose of T3 exactly 12 hours before blood test

[PCAD]

This base value is low, even for 11am, although as previously said it should be done before 9am. The test shows that your adrenal glands are producing enough cortisol on stimulation BUT is your body producing the ACTH naturally to do the stimulation itself. They should repeat the test at 9am and also do the ACTH at that point. If you are not producing enough ACTH to stimulate then you are likely to have secondary ADRENAL INSUFFICIENCY as opposed to primary (adrenal glands).

[Angel_of_the_North]

Actually, not fine. Starting level too low (and, given that, very good rise). Also done too late in day. Need testing for secondary adrenal insufficiency/pituitary problems. Usually CT scan or MRI, and (horrid, horrid) insulin stress test.

[Bramble83]

Your baseline is too low, as others have already commented on, however as it wasn’t done between 8 and 9am it is difficult to interpret the result. The SAT can be done at anytime of day and the result is just as valid, so no need to repeat that. You do however, need a 8-9am blood cortisol doing- something your GP can do very easily.

Your stimmed response is excellent, which rules out primary insufficiency.

The obvious next test would be for secondary adrenal insufficiency. You also need an ACTH test to see whether that is low.

I wouldn’t waste your time or money on saliva testing- it is not recognised in the UK by endocrinologists for the diagnosis of adrenal insufficiency as it measures free cortisol, not blood cortisol.