Adrenal Blood Tests

[kp60]

I am getting Cortisol and ACTH blood tests to see how my Adrenals are doing after approx a year on Prednisone. Now at 4 mg daily and struggling a little

My question is should I refrain from taking Prednisone for a period before this test? Thanks!

[SnazzyD]

I was told not to take my morning dose of Pred until after the procedure. At 4mg my results weren’t very good but by 1.5mg much much better. I could tell because I was feeling so muc better.

[kp60]

Thank you for the good info Dad and Snazzy.

[PMRpro Ambassador]

Usually you are told not to take steroids in the 24 hours up to the blood sample being taken. Since most patients take their pred in the morning that usually just means delaying the dose until after the test has been done. Some endocrinologists say 48 hours, others will put you on hydrocortisone for a time before the test. It depends on the context and for PMR/GCA patients the 24 hour option is enough - at 4mg there is likely to be some suppression of cortisol production still and some endos won;t do the test until you are at 3mg and even then it is no more than an indication for many.

Is it being done at a local hospital day clinic? You can ring them to get information perhaps or to find out who to ask what their usual protocol is.

[Seraphina56]

I had a short synacthen test done by an endocrinologist. My rheumatologist wouldn’t refer me till I’d been on less than 5mg Pred for at least 2 months. So I had it done at 4mg and it was normal. I’d been on Pred for 4 and a half years. I had to delay my morning dose till after the test.

[kp60]

So confusing. My doc just told me not to discontinue my prednisone before the cortisol and ACTH blood tests because they want to see how my Adrenals are working on Prednisone.

[HeronNS in reply to kp60]

That is very confusing. I wonder if there's a problem with terminology? You wouldn't actually be discontinuing the pred, just delaying your dose. Like when you have blood sugar tested and have to fast beforehand. You haven't discontinued eating, just delayed your breakfast! 😉 In any event I think a bit of clarification is needed.

I didn't have the ACTH, but for morning cortisol my doctor said no pred for at least 24 hours and 3 days if I could manage that. I had no pred for something like 58 hours and the cortisol level was exactly in the middle of normal range. I would have thought taking pred shortly before the test would have completely overpowered what my body was producing. But, hey, I'm not a doctor and maybe they have their reasons.

[PMRpro Ambassador in reply to HeronNS]

I think - not sure - that the not taking pred in the 24 hours before the blood is taken is less the effect on the adrenal glands, that won't change much in 24 hours, but interference with the assay itself.

[HeronNS in reply to PMRpro]

Yes, thank you, I think that's what I was trying to say, in a muddled way!

[NursePeggy in reply to PMRpro]

I had a cortisol test recently having not had my pred (7.5 mg) for 24 hours. The result was 24. The endocrinologist said not to worry because the pred was not included in the result. It was working on top of that. I dont think I have phrased that very well.Is the endo right or wrong ?

[PMRpro Ambassador in reply to NursePeggy]

In terms of your body functioning yes - but that isn't the point really. As the dose of pred reduces, the adrenal glands must start to top that up to get enough corticosteroid for normal function without oral pred. The basal cortisol test is to show if they are doing anything. But a bit pointless doing it at 7.5mg which is the amount the body requires - the feedback set-up will be switched off entirely at that dose. As was seen - anything under 100 indicates adrenal insufficiency.

[NursePeggy in reply to PMRpro]

I have only been able to reduce to 6mg. I could hardly function so was told to go back up to 7.5 again. The endo now says not to go below 7 mg. although I just had a small flare and went up to 10 for a few days. Am now back at 7.5. I have also had a few low blood pressure fainting episodes. But that could be because I have Histamine problems.

My brain is finding it very difficult to understand Cortisol, Adrenaline

etc.

[PMRpro Ambassador in reply to NursePeggy]

It can take a long time - I'm sure Snazzy's story is about somewhere. And it is a point where - if the PMR allows - switching to hydrocortisone may help.

[SnazzyD]

No, once my Synacthen test was ok on 1.5mg, they didn’t bother again. I’ve had a couple of phone calls over the last 18 months and I’ve told them about a few crises I’ve had.

[SnazzyD]

Well yes in as much as needing a couple of mg Pred to get out of a sudden episodes of all the signs after a period of sustained physical or emotional stress.

[SnazzyD]

My crisis inducing pain on one occasion was walking up and down small mountain for 4 hours with acute tendonitis. Thought I could do it but turned out at the point of no return I couldn’t. At first I thought I had a low blood sugar but snacks didn’t help and then other symptoms kicked in and I felt a bit stupid.

[kp60]

Well, not to beat a dead horse... but as clarification I asked if I shouldn't take Prednisone for 24 hours before the tests (I take in am and in evening) and doc said no. " Keep taking as usual as we want to see how your adrenals do on the prednisone".