Posted by bleauberry on January 23, 2010, at 12:03:12
In reply to Re: CFS! Lymes? CD? Cortisol fasting? Salty taste?, posted by tea on January 22, 2010, at 2:29:17
The saliva test is as accurate or more so than the blood test, so no need to fast. You can even do it in bed as soon as you wake up.
The morning-only test is flawed, because it "assumes" that your entire daily cortisol curve is following a normal pattern. It can be completely backwards, to where cortisol excessively high in the morning, but terribly low when it is supposed to be high. That happened to me. If I had taken the morning-only test, a doctor would have said my cortisol was fine because it was higher than normal, when in fact it was inthe dumps off the bottom of the graph all the rest of the 24 hours.
All a single test will do is tell you how much cortisol is at that particular hour...without any reference to how that compares to your cortisol the rest of the day. It does nothing to show the true picture. With cortisol, the amount present on a lab graph is only half the story, and is meaningless without the other half...which is, what does the entire 24 hour curve look like. Two tests a day is also not enough. Four minimum is needed, and some labs do 6 per day.
> > Must I fast for a cortisol test?
> >
> morning cortisol blood test (if I recall right) is just crawl out of bed, don't drink, eat or even clean your teeth (probably wera your clothes to bed to save any effort), then get someone to drive you to blood test first thing on waking if possible (our test places open about 7.30AM), and get blood test about 7.30AM-8AM. then go home have brekkie etc. best if also get an aft test about 4PM to compare the two.
> Doing anything supposedly causes the blood cortisol to rise and you want to test if it is low on waking. if you could just test it in bed, even better! LOL That's from memory. It's tot tst if your sortisol rises naturally overnight as it should to OK levels or if not.
> Afternoon does not have to be fasting. Gee my recall is poor, I think about 4PMish?
> Hope this helps as to why they say that about the fasting.
>
> Sorry I clean forget what the salty taste means... had it and now forget.. back in 2002-2203 ish
poster:bleauberry
thread:934569
URL: http://www.dr-bob.org/babble/20100122/msgs/934780.html