Catecholamine Blood Test

[yikespanic]

Had my follow-up appt with Dr Grubb's nurse pract Bev yesterday. She is just as nice and through as he is, and the wait to see her was only 10 minutes. She ordered the catecholamine blood test, and they were able to do it right there at the Lab. I had to lay down for 30 min, they drew blood, then briskly walk for 30 min and then have my blood drawn again. What exactly will this test tell them? All I could find was it might help find tumors, (scared me).

On a good note, the trial of celexa has helped me. She upped my dose alittle and were going to see if it helps a bit more. My BP isn't shooting up, the racing heart still happens though not nearly as often and not as long in duration. My BP is still low but I'm not see stars and getting all the nasty other feelings as much. My anxiety levels have dropped and it is a bit more managable. My hopes are up. My fatigue is still a problem and we are going to work on trying a new med for helping me sleep that just came out that doesn't have any side effects. Hopefully with some better sleep the fatique may improve. I sure hope so.

Kim

[Ernie]

HI,

They will know if you have hyperadrenergic POTS.

[lthomas521]

They're probably not looking for cancer. There are some rare tumors that secrete catecholamines, but only about 10% of them are malignant.

One theory of POTS is that it is due to abnormal norepinephrine reuptake. Nerve cells in the autonomic nervous system secrete norepinephrine into the synapse (the gap between one nerve cell and the next) in order to send a message to a neighboring cell. Then, the norepinephrine is usually picked up by a special protein (called a norepinephrine transporter) on the surface of the nerve cell and brought back inside the nerve cell. If you don't have normal norepinephrine reuptake going on, then the norepinephrine "spills over" from the synapses and into your bloodstream. So you will have high catecholamine levels when you stand up. (Norepinephrine, also called noradrenaline, is a catecholamine.)

There are several reasons why norepinephrine reuptake might be subnormal. Some drugs (notably some antidepressants) block the norepinephrine transporter, which is evidently why they have orthostatic hypotension as a side effect. Also, a few people have been born with a mutation in the gene that carries the recipe for the norepinephrine transporter. Lately, researchers in Australia have been pursuing the theory that lots of people with POTS have a normal NET gene, but the gene is switched off, so it is not making norepinephrine transporters. Genes get switched on and off for various reasons, which is why different types of cells look and behave differently, even though all of your cells have the same DNA. Now if we can only figure out why our NET genes have been switched off!

[Poohbear]

It would be nice if some of this research you mention is actually published. So far, you keep talking about this research and saying articles are pending but nothing has been printed or proven.

[Lukkychrm42]

Click here for a recently-published study that explains some of that, but I believe they're the ones that identified the gene for Hyperadrenergic POTS, and it says there's an actual "mutation." How that contributes to the mechanism of it, or otherwise, I suppose is still in the works, but I guess we'll find out eventually!

[gwen]

thank you for sharing the study! I am greatly interested in reading these, but don't know where to find them. do you google or is there some other site that lists these as they seem to come from a variety of journals? thanks again!:-)

[kmpower]

Thank you soooooooo much for this!!!!

I especially loved the part where it said that the usual tests for anxiety include POTS type physiological symptoms like palpitations. When they did a different test for anxiety which was separate from the body responses to orthostasis, POTS patients had less anxiety than the "normal" population...which is to say (as if we didn't know) that the diagnosis of anxiety is less correct with us than POTS or related disorders.

The rest is very helpful, too.

Thanks again.

OLL

[lthomas521]

It would be nice if some of this research you mention is actually published. So far, you keep talking about this research and saying articles are pending but nothing has been printed or proven.

Every week, I check the New England Journal of Medicine to see if the article has come out yet. Maybe Ramakentesh will give us a heads-up when the article is accepted for publication.

In the meantime, here are some other, related articles:

Mandela P, Ordway GA. The norepinephrine transporter and its regulation. J Neurochem. 2006 Mar 15;

Shannon JR, Flattem NL, Jordan J, Jacob G, Black BK, Biaggioni I, Blakely RD, Robertson D. Orthostatic intolerance and tachycardia associated with norepinephrine-transporter deficiency. N Engl J Med. 2000 Feb 24;342(8):541-9.

The Shannon article discusses the identical twins with the loss of function mutation in the norepinephrine transporter. They had POTS and the norepinephrine spillover because they had norepinephrine transporters that didn't work properly. From what Ramakentesh has told us, the folks at the Baker Institute theorized that some of the rest of us have a normal NET gene but no expression of the gene. She explained that they used several different independent methods to document the abnormal expression. Very encouraging.

It makes sense that people with POTS would have less anxiety than normal people. A friend of mine is a psychiatrist who works in antidepressant research. When I told him about the norepinephrine transporter theory of POTS, he said, "How can you live like that?!" I said, "Not well, obviously." He said, "It would be as if you are on a huge dose of antidepressant." I said, "Well, then it's no wonder I'm so stable emotionally!"

[Guest Belinda]

Hi Yikes..hope the tests go well and you donnot be found to have the hyperadrengic form..let me know how it goes..hope you are doing well..Belinda

[ramakentesh]

As an update on that study - the Baker Institute checked all 14 POTS patients by taking a 1cm vein biopsy to check for NET protein - it was almost completely absent in all POTS patients and normal in all normal subjects. It looks like a winner.

[Gena]

When I was at Mayo in Jacksonville they only did a 24-hour urine test for catecholamines. Is that an accurate test? Mine came out normal. But I don't see how basedon my symtpoms!

[Sunfish]

gena -

the test you had is accurate for what it's designed to test for, but it has a different purpose than the supine/standing test that others are discussing. essentially the give different information...related but not the same pieces of the puzzle.

melissa

[Guest tearose]

I think it is wise to take the results of this test and look at what else is going on with you....

I too had high levels of norepinepherine BUT since my thermoregulatory sweat test showed small fiber nerve damage, my levels of norepinepherine are understood as a "normal" response since I have no NET deficiency.

best regards, tearose