Hi Sue,

Those reference ranges on the sheet are based upon the 17 OHP levels of children at around 8am I would say.  They are not based upon what a CAH childs levels are before  their synthetic peak of hydrocortisone because they have sually not taken their med’s before the blood tests.  When they set acceptable reference ranges for blood tests, they go by data that has been gathered from studying a group of normal healthy children’s 17 OHP levels or ACTH levels or cortisol levels etc.  

If you imagine what will have happened for the average normal child by the time they get to the blood lab to be involved in those studies, you will then realise that they would have had their morning peak of cortisol, which is the largest peak.  In sharp contrast to this, we are asked not to give our kids the meds before a blood tests at 8am more often than not, so because they have a reduced inability to make cortisol, the reason their 17 OHP comes back higher  than a normal healthy childs is because they didn’t make cortisol and possibly were making 17 OHP.  Neither did they have their med’s to factor that in often. Your Doctor MUST factor in whether med’s have been given or not here to get things right.  If you had given med’s and the 17 OHP was low range--then fine, this is acceptable.  If you have NOT given med’s since 10pm night before and the 17 OH is in the low end of the ranges this is NOT acceptable.  

The last dose of cortisol to be given to them is possibly between 10-11pm at night on conventional dosing.  Those reference ranges they settled at therefore for CAH children, are what they settle at after having done perhaps years of studying and analysing these facts and knowing all the above. 

For instance to have one of our children have the same levels as a non-cah child at 8am in the morning, you can imagine the huge amount or dose of hydrocortisone they would need to be given at that last dose of 10pm to make sure that it was bringing them into the same ranges.  They go nearly 9-10 hours from 10-11pm before they have that morning blood tests.  On top of this--most cortsol peaks take place around 7-8am, but if you rise earlier I would imagine this peaks earlier.  So our kids are having their bloods taken after the adrenals have already tried to make cortisol at that 7am spot and also they have gone 10 hours without meds which also seems now from studies to be excreted 6-8 hours later depending on their severity of CAH.

So over time I would say that Doctors doing studies around growth and what levels effect a good growth rate for CAH kid’s determines how much steroid we give anyone child last thing at night.  To control them so that their 17 OHP was what it should be in a normal child would be in effct over treating a child and stunting their growth because they haven’t got the advantages of normal children to start with in making the cortisol that normal healthy children make as they rise and prepare for their blood tests.  That is why they suggest 500-1000ng/dl, which is higher than normal, but perfectly reasonable when you consider that the CAH child did not start making cortisol right away to suppress 17 OHP levels to what a normal healthy childs adrenals would first thing in the morning.

With that said, giving the hydrocortisone at 3am is some 5 hours later than giving it at 10-11pm and WOULD make a difference to morning blood tests.  In fact, I feel to control kids on the circadian dosing between 500-1000ng/dl would result in gross under treatement really.  There is a big difference in taking bloods 5 hours from after a drug was taken and ten hours after.  You cannot expect the 17 OHP levels to be the same for one thing.  The difference is "some" cortisol still being their enough to suppress 17 OHP if you dosed at 3am and none at all--as it would be if dosed at 10pm--- causing 17 OHP to be higher.   As yet after doing many searches, I see nothing about that, but plenty about the reference ranges for children dosed conventionally--so I feel there could be a problem of kids having periods of undertreatment if 500-1000ng/dl is the reference range used for circadian dosed kids.   Dosing at 3am would mean that the reference ranges should be somewhat lower where 17 OHP is concerned.  

Well that’s my guess anyway, and I won’t be having Ashley controlled with those ranges if I can help it.  At the moment I was trying to establish a balance really and keep an eye on his growth and see what his growth patterns are like.   I feel that that is the best thing to do and to keep the 17 OHP at the lower end of those ranges to be on the safe side for the time being.  In fact I feel because we are dosing them as cortisol would normallly secreted now, we should be looking at the normal ranges for normal healthy children as a good guide as to how to control them for maximum growth.  If your child is dosed conventionally as yours is though, I would really be looking at 500-1000.  Especially as a baby.  The problem in the past as been to  over treat babies and they have now realised that this is not a good thing and that the growth never catches up when it is lost to over treatment.  I would discuss this with your childs Doctor in more depth.

Cheers

Anne-Marie