Synactthen test

[Johnone1940]

Could anyone give me a fuller explanation of the following please . I have just had the medical report for the Synacthen test that they i recently had at my local hospital. It states that “my baseline cortisol was 248 and that the 30 min cortisol was 369 implying that this was a sub-optimal test therefore this suggests that he has ongoing adrenal insufficiency.” Does this mean that my adrenals are no longer capable of working or are capable of working . At my first consultation the Consultant said that depending on the results of the test I could stay on preds or be transferred over to hydrocortisone in order to try to wake up the adrenals. At the moment I am taking 3 1/2 mg per day. Depending on what my consultant says when I go back to clinic, should I opt for staying on the preds or changing over to hydrocortisone? He said it would be my choice.

[SnazzyD]

I had the same issue at 4mg. My endocrinologist was of the opinion that my adrenals needed more challenging before giving up so I was instructed to keep reducing and sure enough by 1.5mg they were much better. It took a good year after stopping Pred Aug 2020, to feel out of the phase of good days and not so good days. However, I’ve been caught out a few times when I’ve had sustained unusual stress or pain and had to have a rescue mg or two.Perhaps your doc feels that having hydrocortisone that wears off more quickly through the day than Pred is more of a challenge rather than seeing it as your adrenals are permanently poor.

However, one thing to bear in mind is that although this is a small dose now, it may be enough to stand between you and a flare. Some docs appear to think that once you get below 5mg without flaring, your condition is done and dusted. It was for this reason that I was happy to stick with Pred and reduce at my own speed which was a lot slower than the Endo’s plan of 1mg per month.

[PMRpro Ambassador]

A baseline cortisol of 248 is within the normal range quoted and a value of under 100 is taken as indicating likely adrenal insufficiency even without doing the synacthen test. A baseline of above 450 is taken as normal adrenal function. A result between those two levels is equivocal and a synacthen test is recommended to clarify.

pubmed.ncbi.nlm.nih.gov/286...

When the synacthen test is done, they expect to get a 30 min level of above 420 to show adrenal function is normal - yours was below that so considered "suboptimal".

gloshospitals.nhs.uk/our-se....

But you are still on 3.5mg - and most endos want to wait until the pred dose is 3mg before looking as even that small amount will suppress adrenal function. What your results show is that there IS potential function there and as you reduce the pred it will settle down and improve. Switching to HC may improve the rate at which it returns - but may not be as effective in managing the PMR symptoms if it is still active since it isn't as strong and the advantage it has of being excreted from the body quicker so stimulating the return of adrenal function means it must be dosed at least 2x and possibly 3x daily to manage the PMR symptoms well. It is a corticosteroid so has similar side effects and everyone responds differently. Some do very well with it, others don't.

There are a few people on the forum who use HC and at least one person who couldn't cope with the HC side effect so went back to pred. At least your rheumy is allowing you to make the decision.