preparation for cortisol blood test

[Avadip12]

fatigue and adrenal function has been top of my list for months , as I just can’t cope with the low level of energy and weakness I have . I have been banging on about this for so long now , everybody it fatigued with me . Anyway my GP has given me a blood test form for a morning cortisol. Can you knowledgeable ones please tell me how to prepare for this. Do I stop my steroid before,I am on 4 .5 mgs . Many thanks

[PMRpro Ambassador]

Yes - if you take your pred in the morning, don't take it until the blood sample has been taken. You need a full 24 hours without pred before the blood sample is taken.

[Leafsong66]

I hear you! All the best with your test. I couldn't handle the fatigue etc either of 4 mg and am back to 7mg with much better results. Will continue to taper but now much more slowly. I let my Rheummy confidently put me on a rapid taper. NOT good!

[Avadip12 in reply to Leafsong66]

Thank you

[Zebedee44]

I had this test done recently and had to be at the hospital for 9am having NOT taken my daily dose of pred as advised by the GP. Since then I have been taking my dose later in the morning in an effort to encourage my adrenal glands to do their bit. The phlebotomist told me that the release of cortisol occurs between 8 and 9 am hence the 9am test.

At 5.5mg pred I wasn’t expecting great things but the result was 246, indicating a small release of cortisol. I am feeling the effect of this recent taper with some classic PMR pain and low energy, but that might be the weather!

Ps.I took a small pot of yoghurt to eat after the blood test when I took the pred. In and out of the hospital in 15 minutes but I still had to pay for parking!

[PMRpro Ambassador in reply to Zebedee44]

Not QUITE right - the peak cortisol is shortly after we wake for the day so about 8.30am for most but the release starts much earlier, Then there are small releases coinciding with mealtimes.

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

Figure 1 shows the release of cortisol over the day - look at that even if you don't read it.

Under 100 would have meant adrenal insufficiency, over 450 would have been normal. Your 246 is pretty good for someone in 5,5mg pred and augurs well for your continuing taper!

The important level is the level at midnight, as shown on the graph in the link. That nadir is what triggers the HPA axis to signal for the production of cortisol in the early morning. For us it is achieved by taking all our pred as early in the day as possible - the later you take it, the less time it has to wash out of the system before midnight,

If all they did was a basal cortisol, why did you have to go to the hospital? Does your GP not take blood samples?

[Avadip12 in reply to PMRpro]

My last test showed it was 190 which my Dr said was normal . ?

[PMRpro Ambassador in reply to Avadip12]

It is in normal range for morning cortisol - however, it is the synacthen test that would determine whether the adrenal function is normal. It might STAY at 190 after the injection of synacthem - and that isn't normal!

[sylla123 in reply to PMRpro]

I have never been asked to have a Cortisol blood test , I wonder why ? Would it be OK to have it around 11am ? I will ask my doctor about it as I have atlast managed to get a phone appointment next Tuesday 19th. I am only on 2 Pred now having started again beginning of February when I had finished Jan 1st and started pains round shoulders. but the fatigue is the worst that never goes away , my muscles seem knackered .. I have started some exercises now with a Physio so I am hoping to gain some strength to support my body ..

[PMRpro Ambassador in reply to sylla123]

Probably because most GPs rarely have to deal with long term corticosteroid patients and just assume they will slowly taper to zero and all will be fine. For a majority that may be true - but a sizeable minority struggle and it takes a lot longer for adrenal function to be back to normal.

[sylla123 in reply to PMRpro]

Thank you PMRpro

[DorsetLady PMRGCAuk volunteer in reply to sylla123]

You don’t get offered one unless you are having problems, you need to do the asking. And around 9am is recommended time…

labtestsonline.org.uk/tests....

[sylla123 in reply to DorsetLady]

Thank you DorsetLady

[Zebedee44 in reply to PMRpro]

My GP was trying to get ahead of the endocrinologist investigating my recently diagnosed pituitary adenoma and this necessitated getting the bloods taken at the hospital. There were some tests that had to go straight to the lab at 9am and one that had to be stored on ice. The Endocrinologist needed more tests done so I had a second early morning appointment. This second test has revealed the high level of prolactin which seems to have caused the tumour. I will know more on Tuesday when I have a video consultation with the Consultant.

[PMRpro Ambassador in reply to Zebedee44]

All the best!

[Avadip12 in reply to Zebedee44]

Thank you

[ImC_]

Me too! I am tired of being tired - having to have lie downs throughout the day. Can only really do one main thing a day.

I am on 3.5mg/3mg ( in middle of slow taper).

I am not clear if my fatigue is because my level of Pred is controlling the pain and stiffness but not the fatigue - ie PMR still going strong - or whether it is because the adrenals are groaning back in to life - except that I have been below 7mg for a long time - since early 2022. (Not really sure why I am taking so long to reduce! Very cautious I suppose .)

I asked my GP a while back about a synacthen test. She said something like ‘we don’t do that’ or ‘only rheumatologists do them’. I did not have info to hand at the time so could not argue this. I’m in south London. Is there something I should be pushing for?

I’ve been fatigued all year, really. It’s getting in the way of things.

[PMRpro Ambassador in reply to ImC_]

That is a typically difficult dose - almost enough to suppress cortisol production in many patients but not quite enough to replace it fully despite a study from Imperial London being of the opinion 2mg pred is enough to replace cortisol requirements,

The GP can do a basal cortisol test for you - it gives a good indication of whether there is any point doing a synacthen test. If the basal cortisol in a sample taken between 9am and 1pm is under 100, then the patient almost certainly has adrenal insufficiency. If it is over 450, adrenal function is normal. Results inbetween are equivocal and require a synacthen test for clarification.

Some others on here. SnazzyD for one, really struggled at that dose and cortisol was low. By persisting and sticking it out, their adrenal function did improve. But it is a slow business and probably means a long time accepting a lot of limitations.

[ImC_ in reply to PMRpro]

Thanks for this, it’s something clear I can put to the Doc.

[sylla123 in reply to PMRpro]

PMRpro You are all so helpful on HU, That is a lot of very useful information in this post/reply to imC_, things I hadn't a clue about ! As I am only on 2pred I will stick with that. What I thought might be a flare up , might only be the fatigue of my muscles and tendons after living with PMR for over 2 years and keep up my new program of Physio exercises ...

[PMRpro Ambassador in reply to sylla123]

"and keep up my new program of Physio exercises ..."

If you feel they are too much for you FOR NOW tell the physio you want them eased/adapted, I was at an on-line seminar the other day and the physio researcher running it emphasised the exercises MUST be adapted to the patient. If it is too much now - go slower.

[sylla123 in reply to PMRpro]

Yes that is certainly right , and my Physio who I can always contact quickly if I need advice has already told me if when doing the exercises the pain goes above 4/10 to stop and I have one day exercises then one day day rest. It is early days yet as I have only started a week ago , and most of that time was spent getting used to doing them right and I have a video of each exercise to remind me ...The Physio I attend is "DynamicHealth MSK Specialists & Physiotherapy Services" Cambridge and Ely Branch .

[PMRpro Ambassador in reply to sylla123]

Love the idea of a video to check. But nothing beats hands on correction.