ESR and CRP results, adjustment for age?

[PMRnewbie2017]

I have just seen my results for my annual general health GP review. I was disappointed that my ESR and CRP results were higher than last year. Then I thought about it and did some research.

Last year (June 2022) I was taking 4mg Prednisolone, My ESR was 19mm/hr and CRP was 6mg/L. Now I am taking 1.5mg Pred but ESR is 23mm/hr and CRP is 9mg/L. I feel totally PMR free, have got through the tricky stages of adrenal insufficiency episodes while reducing and feel better than I have done for many a year. I know that ESR is higher in females and rises with age. Through a Google search I came across Miller's Formula for adjusting ESR and CRP to account for sex and age. There are also a few papers out there from Rheumies suggesting that age adjustment should be taken into account when diagnosing and treating RA patients. If I apply the formula to my results, they become within normal limits.

Has anyone else considered the effect of age on their results? At my last Rhemy consultation in 2022 he wanted to add MTX because of my results - of course I refused. This is another instance of symptoms trump blood results and the results have to be looked at as part of a bigger picture. The GP wants to see me to talk about my results, goodness knows what sort of a conversation that will be?

If interested the formula is:

ESR: Age + 10 divided by 2 in mm/hr

CRP: Age +30 divided by 50 in mg/dL . Most UK results are quoted in mg/L so multiply result by 10.

[DorsetLady PMRGCAuk volunteer]

I penned this a couple of years ago -and from what I found your levels are within normal ranges anyway (but you have to take account that level of Pred you are taking may distort true level ). Scroll down to find reference ranges.

Not sure that adding age formula is used very much nowadays…

healthunlocked.com/pmrgcauk...

[PMRpro Ambassador]

I think the Miller formula is disputed and there is a degree of acceptance that the rise with age is not purely age-related but because old er patients simply have a greater level of undiagnosed inflammation

If you apply it to me - not sure what it says, My measured "normal" ESR is 4, during a big flare it runs about 16-18. And my CRP only increases with a cardiac problem ...

[cranberryt]

My lab lists the normal range on the results report. I noted when I turned 50 that the ESR normal limit changed from 20 to 30. Normal CRP range on my report has always been less than 0.5. That didn’t change with age so far.