Could pituitary tumor be causing POTS?

[LivingInHope]

I was looking over some old labs and some info on aldosterone and renin from a couple of sources.  While one source says people with POTS w/hypovolemia have paradoxically low renin and aldosterone levels and the cause is not exactly understood- they hypothesize perhaps the kidneys are being denervated, another site says if aldosterone and renin are both low they think there could be a problem with the pituitary.  

Since my tumor was discovered, the first endocrinologist I saw ordered aldosterone and renin testing.  It was a fasting test where both aldosterone and renin were low.  One endocrinologist did not want to re-test these things as if even if they were low, he said there was nothing that could be done about it.  I did just find online something about a test on rats where aldosterone is lower with fasting apparently.  But I wonder if it makes aldosterone outside normal range?  Anyway, a third endocrinologist tested aldosterone only & I wasn't fasting, and it came back normal.

Another website about another experiment with rats indicated ACTH and GH had an affect on aldosterone.  And it looks online like the pituitary also has something to do with renin secreting (feel out of my league there as to whether that renin angle is a piece of puzzle that would fit my situation so to speak).  I'm just wondering if it is possible whether my pituitary tumor could be causing my POTS?  And if so, if some other people with POTS might have pituitary tumors and not realize it?

[rumpled]

I had reversed rhythm with my Cushing's too - nothing like not sleeping all night and dragging all day, huh... :(

The fludro alone cannot take on the Cushing's - it is just treating one symptom. I was put on at the end of my Cushing's journey and now I still take it that I am AI. Because your cortisol fluctuates, your body cannot regulate quickly, or so my cardio said at the time, the changing fluid dynamics and it would give me weird heart stuff like tachy etc. For a while I carried around beta blockers to take when I needed, but could not take at all times as my BP was normally too low, it would make me too low.

I take my fludro with salt... have you been able to track a cycle so you know when to take it - or are you all over the place?

[phelyne]

I'm now taking fludro for aldosterone issues. At last appointment, cyclical cushings was still on the table but the leading theory was my circadian rhythm is reversed. My cortisol is often double the range on 10 hr night time urine collections, and low normal duing the day. Initially my aldo was low and renin high, but when I tried salt alone it caused swelling, hot flashes, wired insomnia, headaches. At  followup aldo was still low but raised a little, and renin was low, so this was when I was put on florinef in addition to salt. I swear, some days I can't function wthout it, and some days I feel more cushie like with it. There have been 2 times I stopped taking it for a week with similar ups and downs. I'm confused.        

[LivingInHope]

I'm glad you've found a doctor who will help guide you on the salt business!  I've actually kind of grown used to the tachycardia & my recent echocardiogram seems to have shown a blessed, amazing improvement over my last one!  Last year's showed mild tricuspid & mitral valve regurgitation and this year's showed no tricuspid regurg and trace to mild or something mitral regurg!  Maybe I'll ask my primary doctor at my next appt. if he can order renin and aldosterone testing or not.  Did you ever get your adrenals scanned & if so did it reveal anything?  Also, can you explain to me what you meant by this? "but also AI can vary a bit with the renin and aldosterone"
Thank you for responding!

[rumpled]

Alas, the websites are one thing, but there are sometimes nuances, especially with Cushing's, that can cause things to be slightly different. Conn's should not vary, but also AI can vary a bit with the renin and aldosterone. So while the charts may say it IS this, real patients can and do vary. My ACTH never was high with pituitary Cushing's which should have been adrenal, for instance - so it really takes looking at so much more. If you have a cyclical case, your testing is totally different than a florid case. I had the low BP when most with Cushing's have high - it just happens. Plus if the neuro-endo you saw is not an expert with Cushing's (not all are, sadly), they may have made an error. I saw oh... 5 neuro-endos that mis-diagnosed me.

My doctor told me how much to take. I also have latitude to take up to ten tablets in a day (never  have done that though!) if things get bad and he prefers that I play with the salt and not the florinef. I have really low BP and the POTS issues, see a cardiologist, and have to have salt daily. I take the NaCL tablets. I use sea salt on food as it tastes better, but sea salt actually has less sodium, so I don't use that to make tablets. I buy them, unbuffered.

[LivingInHope]

Well, the neuroendo I saw doesn't feel I present as someone with Cushing's.  I looked up Addisons which you mentioned and on NIH gov's website, it was saying secondary adrenal insufficiency comes from a lack of ACTH. They say basically the result is the adrenals’ production of cortisol drops. Then they state that production of aldosterone is not usually affected.  So if my cortisol is okay, I guess the ACTH wouldn't affect aldosterone alone.

I've never had my adrenals specifically examined to my knowledge, though I had wished it in the past due to wondering if I had a pheochromocytoma.  An endocrinologist I forgot I saw in relationship to that prior to knowing I had a pit tumor felt there was no way I could possibly have it, even though my internist was the one who brought up wondering if I had one & she was not going to order any imaging about it.

  Noticed this time you mentioned Conns, so I looked that up, but it looks like that is excess aldosterone rather than too little.  I'm guessing my pit tumor is not causing my POTS or if it is, no one wants to test me further since I don't look like a someone suffering from Cushings.

I'm glad you've got a system for your sodium worked out & I have an excerpt from an article that recommends sea salt over table salt related to aldosterone.  Did a doctor help you with the amounts or did you just figure it out by trial and error?

[rumpled]

It does in the case of Cushing's disease - where the cortisol messes with everything. I failed that test too, but I had it - no test is perfect so you need more than one test to rule it in or out, especially if you are cyclical or are mild (in form of test levels, not symptoms, I almost punched the doc for calling my case "mild" :) ).

I also take salt. If you started your florinef incorrectly - i.e. did not taper up slowly, you would have terrible side effects. I have POTS like symptoms as well - I take salt tablets - 1gram each, and take one in the morning, one at night, and carry with me to take when I sweat, have activity or my BP drops etc. It is at the point where my hubby can actually tell when I need salt!

Tablets help as it is less calories but I also carry sea salt like a weirdo as I like the taste since I salt heavily and table salt tastes horrible.

I also wear compression stockings from time to time - lovely...

[LivingInHope]

I read a little further on and saw that pituitary doesn't usually affect aldosterone production.  Guess I struck out on that theory.

[LivingInHope]

I don't think I discussed it that I can recall with that endo (whom I was none to impressed with) but a cardiologist already tried midodrine and florinef with me for my POTS and with the side effect issues (I think the first I got chest pains more and the second may have been headache issues), he decided I should just eat a lot of salt.  The cardio told me those pills only help about I don't remember if it was 40 or 60 percent of people with POTS.  And after I tried them, he decided natural (eating salt) was best w/me and I could wear compression stockings if I wanted.  But no doctor ever told me how much salt, so I've been left to fend for myself about it.

The neuroendo at Vanderbilt didn't feel I presented as someone with Cushing's.  She did a cortisol stimulation test (normal).    She didn't order any renin or aldosterone tests and I'm wondering if I might have secondary adrenal insufficiency from my pituitary.

[rumpled]

First of all, there is absolutely something  you can do about it, so I don't know what your docs are thinking...

Aldosterone and renin issues are treated with florinef or fludrocortisone acetate.

I can explain the issues with the test changes that may or may not be fasting, but lab error. Renin, like ACTH, degrades in minutes when it is drawn and needs to be spun and froze asap.

Aldosterone and renin issues happen with Cushing's, Addison's, Conn's, and other issues. Taking florinef resolves the blood pressure issues. I take it as my renin is high. I also took it when my renin was low - weird, huh. But Cushing's is known to have an effect on those hormones. Why your doctor does not know is crazy.

The test is supposed to be done fasting, and really standing to be proper. But few do it that way.