Cortisol level

[Wheelygood99]

Hello. I'm now down to 5.5mg prednisolone after a year, feeling not too bad. At a recent annual check for my Type 1 diabetes, my consultant requested my cortisol level to be checked. The result at 9am was 170nmol/l. It has been recorded as 'normal'. I've checked and there seems to be a huge range that is classed as normal. I've no idea what my level was before taking prednisolone. Is this level ok?

[DorsetLady PMRGCAuk volunteer]

5.5mg is still quite high for cortisol to be tested - most Endos prefer patient to be at 3mg. At 5.5mg the Pred is still affecting the ‘normal’ levels a considerable amount.

Normal values for a blood sample taken at 8 in the morning are 5 to 25 mcg/dL or 140 to 690 nmol/L.

Normal values depend on the time of day and the clinical context. Normal ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your provider about the meaning of your specific test results.

It is probably noted as ‘normal’ due to the fact you are still on Pred!

[PMRpro Ambassador]

Anything under 100 is considered definitely evidence of adrenal insufficiency, anything over 450 as normal functioning adrenal glands. In between is equivocal and would require a synacthen test to assess if the function really is normal.

Your cortisol level varies through the day, not just for you as a person but also relating to what you are doing and even your state of health. Having a relatively low basal cortisol level like yours is fine - providing that, if the adrenal glands are challenged with a spike of ACTH as you would experience in the "fight or flight" response and as is used in the synacthen test, they are able to respond by producing a similar spike of cortisol. If they can - all is probably normal BUT it doesn't mean the entire HPA axis (hypothalamus, pituitary and adrenal glands and their hormones that act as messengers) is back to normal reliable functioning so care is required.

You are still at 5mg pred - which is loads to suppress normal production of cortisol so as you reduce your pred dose, the cortisol level will almost certainly increase slowly in parallel. As you say, there is a wide "normal range" - and it is a range that was worked out on the basis of measurements taken in hundreds, possibly thousands, of healthy subjects. A few people will be below or above that range and still be OK but 95% of the population fall in that range.

If I was on 5mg with a result like that I'd be happy enough - it doesn't really tell anyone anything much but it DOES tell you that your adrenal glands are at least producing cortisol!

Had you taken your pred that morning before the blood sample was taken? If so, it is possible that the pred in your bloodstream cross reacted a bit with the cortisol assay and made it look better than it really is. But I don't think it is that big a contamination. Do you take biotin for any reason as a supplement? That does interfere.

healthcare.uiowa.edu/path_h....

[GrandmaPirate]

If the laboratorium indicated that it was in their normal range you should be fine. If your PMR symptoms are not disabling you at the current dosage, you should just stay on this dosage. If the symptoms disappear you can try to lower the dosage slowly e.g. to 5mg/day. If you are symptoms free for another month, you may try 4.5 mg/day. It took me 2 years to go from 20mg/day to 1 mg/day. My rheumy keeps me at 1mg/day because I do fine at that low dosage, which is not giving any side effects. I do take calcium tablet and take omeprazole, but the last one I am taking since 25 years because of reflux. Hope you stay well!