Vasopressin

[Guest veryblue]

Has anyone else been tested for their vasopressin levels? I was wondering if POTS can affect them, although mine are so low that they must be a problem with something else. All I know is that low vasopressin causes your body to not be able to hold onto water, which leaves you in a chronically dehydrated state which can cause a condition that looks like POTS. But has anyone else had this test?

[Friedbrain]

Has anyone else been tested for their vasopressin levels? I was wondering if POTS can affect them, although mine are so low that they must be a problem with something else. All I know is that low vasopressin causes your body to not be able to hold onto water, which leaves you in a chronically dehydrated state which can cause a condition that looks like POTS. But has anyone else had this test?

Ancient thread that I found while researching this. Any new answers? I'm still looking into this water/salt/blood pressure balance thing. Had another bad night last night, again after eating peanuts before bedtime. I don't have problems during the daytime after eating peanuts (and don't know if it's directly related to the peanuts, as I've only begun taking notice of a possible correlation). But I definitely had a partial seizure last night as I was falling asleep. I woke up and couldn't move for a few seconds. Had several more minor episodes before finally sleeping almost upright.

Anyway, was wondering if anyone has had their vasopressin tested. I'm supposed to go for a bunch of bloodwork for my endo, and am thinking of calling and asking if I can add vasopressin to it.

Fwiw, I have an 8yr old diagnosis of adrenal insufficiency, and have switched doctors several times since then (moved). It's hard to re-test adrenal function once on replacement, so no doctor has really been able to re-assess that diagnosis. However, in hindsite, looking at the bloodwork with current info out there on the internet, I'm wondering if it isn't a defect higher in the circuit-either pituitary or hypothalamus. For example, one doc along the way questioned the accuracy of the diagnosis (I tried going off the cortef to re-test but had too many problems), and with current info on the internet, I can maybe see why: my initial cortisol level was soooo low that even though there was an increase (3x) with ACTH, the cortisol level never got very high. I asked my current endo about it, and she said that the stimulated cortisol was too low and supported primary adrenal insufficiency; info on the internet says that if it increases >3x, adrenals are able to respond, suggesting a problem higher up. There's a couple other results that question primary adrenal insufficiency, too. Anyway, her reasoning that it wasn't probably a pituitary problem made sense. However, the PVN in the hypothalamus makes both vasopressin and CRF (which ultimately increases cortisol), so maybe it's at the level of the PVN that my brain is busted? That's a long story for a short question, if anyone was interested......

Thanks!

[sue1234]

I have had my ADH, anti-diuretic hormone, tested twice, and both times they were low. I drink alot and urinate alot. I think it was Firewatcher saying they are coming out with a more "definitive" test for all this.

Firewatcher, have you gotten any update on that new testing?

[Friedbrain]

Oh, wow! I apologize for adding to my own post, but I think I just had a Eureka moment! In all of my blood work over the many years I've been collecting, I've always had abnormal BUN/creatinine ratios. Nobody ever commented on it-in fact, often the ratios aren't even reported. The creatinine levels are normal, but the BUN levels are either on the high side or high. (so even when my BUN levels were "within normal limit", the ratio was elevated because my creatinine levels are always perfectly normal). Since I try to investigate any abnormals (which also consistently include abnormal rbc values like MCH), I've been aware of it but never sure what it meant.

Well, I think I know! So......does anyone else consistently have the same kind of result?

My basic understanding is that creatinine is a good measure of kidney function. BUN, filtered in the kidney (produced upstream from breakdown of protein) can also be a measure of kidney function. The two values should be somewhat comparable as a measure of kidney function; ie, both should be proportional, hence the ratio. However, if BUN is elevated and/or the ratio is elevated, it suggests a possible problem above the kidney (ie, not the kidney's "fault" that BUN is proportionally higher than creatinine).

Ta-Da!!! I found that the ratio would be higher in states of dehydration; but also if vasopressin is low, resulting in a decrease in water reabsorption. THat makes sense to me and fits....!

[firewatcher]

Vasopressin, also known as ADH, is difficult to test for. I have had mine tested, several (5) times by reliable labs that know how to handle the specimens (Mayo and Vandy) and mine has always been undetectable even when severely dehydrated (serum Osmolality of 304). Copeptin is supposed to be a more reliable indicator, but the study that was to set the reference intervals has not yet reported its findings. I would not bother having it tested since collection and processing are so specific and there is such a huge rate of error.

As for your blood work over the years, you need to be aware of the current reference intervals to gauge what "normal" is. Until two years ago, my serum creatinine was considered "normal," when it was actually NOT. According to my labs and the current reference intervals, I've been at stage 3 Chronic Kidney Disease since 2006. A high BUN would indicated dehydration, but it could be other conditions as well. It really isn't as easy as "this test says this..." since many of the findings are dependent on the other levels of things (ie.-sodium and potassium regulate one another, if one is high, the other is usually low.)

It is easy enough to test ADH by giving you dDAVP and seeing what happens. If you retain fluids and your bloodwork comes into normal range, dehydration is probably the culprit.